Interrupt List, part 6 of 18
Copyright (c) 1989-1999,2000 Ralf Brown

Table of Contents: by Order by Category

Table of Contents by Order
20 - INT 20 - Minix - SEND/RECEIVE MESSAGE
20 - INT 20 - DOS 1+ - TERMINATE PROGRAM
20 - INT 20 - COMTROL HOSTESS i/ISA DEBUGGER - INVOKE FIRMWARE DEBUGGER
20----Vx0001 - INT 20 P - Microsoft Windows - VMM - VxD SERVICES
20----Vx0002 - INT 20 P - Microsoft Windows - DEBUG - VxD SERVICES
20----Vx0003 - INT 20 P - Microsoft Windows - VPICD - VxD SERVICES
20----Vx0004 - INT 20 P - Microsoft Windows - VDMAD - VxD SERVICES
20----Vx0005 - INT 20 P - Microsoft Windows - VTD - VxD SERVICES
20----Vx0006 - INT 20 P - Microsoft Windows - V86MMGR - VxD SERVICES
20----Vx0007 - INT 20 P - Microsoft Windows - PageSwap - VxD SERVICES
20----Vx0009 - INT 20 P - Microsoft Windows - REBOOT - VxD SERVICES
20----Vx000A - INT 20 P - Microsoft Windows - VDD - VxD SERVICES
20----Vx000B - INT 20 P - Microsoft Windows - VSD - VxD SERVICES
20----Vx000C - INT 20 P - Microsoft Windows - VMD / VMOUSE - VxD SERVICES
20----Vx000D - INT 20 P - Microsoft Windows - VKD - VxD SERVICES
20----Vx000E - INT 20 P - Microsoft Windows - VCD - VxD SERVICES
20----Vx0010 - INT 20 P - Microsoft Windows - BlockDev / IOS - VxD SERVICES
20----Vx0011 - INT 20 P - Microsoft Windows - VMCPD - VxD SERVICES
20----Vx0012 - INT 20 P - Microsoft Windows - EBIOS - VxD SERVICES
20----Vx0014 - INT 20 P - Microsoft Windows - VNETBIOS - VxD SERVICES
20----Vx0015 - INT 20 P - Microsoft Windows - DOSMGR - VxD SERVICES
20----Vx0017 - INT 20 P - Microsoft Windows - SHELL - VxD SERVICES
20----Vx0018 - INT 20 P - Microsoft Windows - VMPoll - VxD SERVICES
20----Vx001A - INT 20 P - Microsoft Windows - DOSNET - VxD SERVICES
20----Vx001B - INT 20 P - Microsoft Windows - VFD - VxD SERVICES
20----Vx001C - INT 20 P - Microsoft Windows - LoadHi - VxD SERVICES
20----Vx0020 - INT 20 P - Microsoft Windows - Int13 - VxD SERVICES
20----Vx0021 - INT 20 P - Microsoft Windows - PAGEFILE - VxD SERVICES
20----Vx0026 - INT 20 P - Microsoft Windows - VPOWERD - VxD SERVICES
20----Vx0027 - INT 20 P - Microsoft Windows - VXDLDR - VxD SERVICES
20----Vx0028 - INT 20 P - Microsoft Windows - NDIS - VxD SERVICES
20----Vx002A - INT 20 P - Microsoft Windows - VWIN32 - VxD SERVICES
20----Vx002B - INT 20 P - Microsoft Windows - VCOMM - VxD SERVICES
20----Vx002C - INT 20 P - Microsoft Windows - SPOOLER - VxD SERVICES
20----Vx0032 - INT 20 P - Microsoft Windows - VSERVER - VxD SERVICES
20----Vx0033 - INT 20 P - Microsoft Windows - CONFIGMG - VxD SERVICES
20----Vx0034 - INT 20 P - Microsoft Windows - DWCFGMG.SYS - VxD SERVICES
20----Vx0036 - INT 20 P - Microsoft Windows - VFBACKUP - VxD SERVICES
20----Vx0037 - INT 20 P - Microsoft Windows - VMINI / ENABLE - VxD SERVICES
20----Vx0038 - INT 20 P - Microsoft Windows - VCOND - VxD SERVICES
20----Vx003D - INT 20 P - Microsoft Windows - BIOS - VxD SERVICES
20----Vx003E - INT 20 P - Microsoft Windows - WSOCK - VxD SERVICES
20----Vx0040 - INT 20 P - Microsoft Windows - IFSMgr - VxD SERVICES
20----Vx0041 - INT 20 P - Microsoft Windows - VCDFSD - VxD SERVICES
20----Vx0048 - INT 20 P - Microsoft Windows - PERF - VxD SERVICES
20----Vx004A - INT 20 P - Microsoft Windows - MTRR - VxD SERVICES
20----Vx004B - INT 20 P - Microsoft Windows - NTKERN - VxD SERVICES
20----Vx011F - INT 20 P - Microsoft Windows - VFLATD - VxD SERVICES
20----Vx0449 - INT 20 P - Microsoft Windows - vjoyd - VxD SERVICES
20----Vx044A - INT 20 P - Microsoft Windows - mmdevldr - VxD SERVICES
20----Vx0480 - INT 20 P - Microsoft Windows - VNetSup - VxD SERVICES
20----Vx0481 - INT 20 P - Microsoft Windows - VREDIR - VxD SERVICES
20----Vx0483 - INT 20 P - Microsoft Windows - VSHARE - VxD SERVICES
20----Vx0487 - INT 20 P - Microsoft Windows - NWLINK - VxD SERVICES
20----Vx0488 - INT 20 P - Microsoft Windows - VTDI - VxD SERVICES
20----Vx0489 - INT 20 P - Microsoft Windows - VIP - VxD SERVICES
20----Vx048A - INT 20 P - Microsoft Windows - MSTCP - VxD SERVICES
20----Vx048B - INT 20 P - Microsoft Windows - VCACHE - VxD SERVICES
20----Vx048E - INT 20 P - Microsoft Windows - NWREDIR - VxD SERVICES
20----Vx0491 - INT 20 P - Microsoft Windows - FILESEC - VxD SERVICES
20----Vx0492 - INT 20 P - Microsoft Windows - NWSERVER - VxD SERVICES
20----Vx0493 - INT 20 P - Microsoft Windows - MSSP / NWSP - VxD SERVICES
20----Vx0494 - INT 20 P - Microsoft Windows - NSCL - VxD SERVICES
20----Vx0495 - INT 20 P - Microsoft Windows - AFVXD - VxD SERVICES
20----Vx0496 - INT 20 P - Microsoft Windows - NDIS2SUP - VxD SERVICES
20----Vx0498 - INT 20 P - Microsoft Windows - Splitter - VxD SERVICES
20----Vx0499 - INT 20 P - Microsoft Windows - PPPMAC - VxD SERVICES
20----Vx049A - INT 20 P - Microsoft Windows - VDHCP - VxD SERVICES
20----Vx049B - INT 20 P - Microsoft Windows - VNBT - VxD SERVICES
20----Vx049D - INT 20 P - Microsoft Windows - LOGGER - VxD SERVICES
20----Vx097C - INT 20 P - Microsoft Windows - PCCARD - VxD SERVICES
20----Vx3048 - INT 20 P - Frontier Technologies ??? - VxD SERVICES
20----Vx3049 - INT 20 P - Frontier Technologies ??? - VxD SERVICES
20----Vx3098 - INT 20 P - QEMM - VstlthD - VxD SERVICES
20----Vx30F6 - INT 20 P - Microsoft Windows - WSVV - VxD SERVICES
20----Vx33FC - INT 20 P - Microsoft Windows - ASPIENUM - VxD SERVICES
20----Vx357E - INT 20 P - Microsoft Windows - DSOUND - VxD SERVICES
20----Vx39E6 - INT 20 P - Microsoft Windows - A3D - VxD SERVICES
20----Vx3BFD - INT 20 P - Microsoft Windows - CWCPROXY - VxD SERVICES
20----Vx3C78 - INT 20 P - Microsoft Windows - VGARTD - VxD SERVICES
21 - INT 21 - COMTROL HOSTESS i/ISA DEBUGGER - GET SEGMENT FOR CONTROL PROGRAM USE
2100 - INT 21 - DOS 1+ - TERMINATE PROGRAM
2101 - INT 21 - DOS 1+ - READ CHARACTER FROM STANDARD INPUT, WITH ECHO
21010F - INT 21 - VIRUS - "Susan" - INSTALLATION CHECK
2102 - INT 21 - DOS 1+ - WRITE CHARACTER TO STANDARD OUTPUT
2103 - INT 21 - DOS 1+ - READ CHARACTER FROM STDAUX
2104 - INT 21 - DOS 1+ - WRITE CHARACTER TO STDAUX
2105 - INT 21 - DOS 1+ - WRITE CHARACTER TO PRINTER
2106 - INT 21 - DOS 1+ - DIRECT CONSOLE OUTPUT
2106--DLFF - INT 21 - DOS 1+ - DIRECT CONSOLE INPUT
2107 - INT 21 - DOS 1+ - DIRECT CHARACTER INPUT, WITHOUT ECHO
2108 - INT 21 - DOS 1+ - CHARACTER INPUT WITHOUT ECHO
2109 - INT 21 - DOS 1+ - WRITE STRING TO STANDARD OUTPUT
210A - INT 21 - DOS 1+ - BUFFERED INPUT
210A00 - INT 21 - WCED v1.6+ - INSTALLATION CHECK
210B - INT 21 - DOS 1+ - GET STDIN STATUS
210B56 - INT 21 - VIRUS - "Perfume" - INSTALLATION CHECK
210C - INT 21 - DOS 1+ - FLUSH BUFFER AND READ STANDARD INPUT
210D - INT 21 - DOS 1+ - DISK RESET
210D20 - INT 21 - VIRUS - "Crazy Imp" - INSTALLATION CHECK
210E - INT 21 - DOS 1+ - SELECT DEFAULT DRIVE
210E--DLAD - INT 21 U - Novell DOS 7 - SDRes v27.03 - INSTALLATION CHECK
210E--DLAE - INT 21 U - Novell DOS 7 - SDRes v27.03 - CLEAR ??? FLAG
210E--DLAF - INT 21 U - Novell DOS 7 - SDRes v27.03 - SET ??? FLAG
210F - INT 21 - DOS 1+ - OPEN FILE USING FCB
2110 - INT 21 - DOS 1+ - CLOSE FILE USING FCB
2111 - INT 21 - DOS 1+ - FIND FIRST MATCHING FILE USING FCB
2112 - INT 21 - DOS 1+ - FIND NEXT MATCHING FILE USING FCB
2113 - INT 21 - DOS 1+ - DELETE FILE USING FCB
2114 - INT 21 - DOS 1+ - SEQUENTIAL READ FROM FCB FILE
2115 - INT 21 - DOS 1+ - SEQUENTIAL WRITE TO FCB FILE
2116 - INT 21 - DOS 1+ - CREATE OR TRUNCATE FILE USING FCB
2117 - INT 21 - DOS 1+ - RENAME FILE USING FCB
2118 - INT 21 - DOS 1+ - NULL FUNCTION FOR CP/M COMPATIBILITY
2118 - INT 21 - U - PTS-DOS 6.51 & S/DOS 1.0 - EXTENDED RENAME FILE USING FCB
211812 - INT 21 - VIRUS - "Tasha Yar" - INSTALLATION CHECK
21187FBX4453 - INT 21 - VIRUS - "DS-3783" -INSTALLATION CHECK
2118FF - INT 21 - VIRUS - "Pathogen:SMEG" - INSTALLATION CHECK
2119 - INT 21 - DOS 1+ - GET CURRENT DEFAULT DRIVE
211A - INT 21 - DOS 1+ - SET DISK TRANSFER AREA ADDRESS
211B - INT 21 - DOS 1+ - GET ALLOCATION INFORMATION FOR DEFAULT DRIVE
211C - INT 21 - DOS 1+ - GET ALLOCATION INFORMATION FOR SPECIFIC DRIVE
211D - INT 21 - DOS 1+ - NULL FUNCTION FOR CP/M COMPATIBILITY
211E - INT 21 - DOS 1+ - NULL FUNCTION FOR CP/M COMPATIBILITY
211F - INT 21 - DOS 1+ - GET DRIVE PARAMETER BLOCK FOR DEFAULT DRIVE
2120 - INT 21 - DOS 1+ - NULL FUNCTION FOR CP/M COMPATIBILITY
2120 - INT 21 - S/DOS 1.0+ & PTS-DOS 6.51+ - GET OEM REVISION
212080 - INT 21 - VIRUS - "New-Year" - INSTALLATION CHECK
2121 - INT 21 - DOS 1+ - READ RANDOM RECORD FROM FCB FILE
2122 - INT 21 - DOS 1+ - WRITE RANDOM RECORD TO FCB FILE
2123 - INT 21 - DOS 1+ - GET FILE SIZE FOR FCB
2124 - INT 21 - DOS 1+ - SET RANDOM RECORD NUMBER FOR FCB
2125 - INT 21 - DOS 1+ - SET INTERRUPT VECTOR
212501 - INT 21 P - Phar Lap 386/DOS-Extender - RESET DOS EXTENDER DATA STRUCTURES
212502 - INT 21 P - Phar Lap 386/DOS-Extender - GET PROTECTED-MODE INTERRUPT VECTOR
212503 - INT 21 P - Phar Lap 386/DOS-Extender - GET REAL-MODE INTERRUPT VECTOR
212504 - INT 21 P - Phar Lap 386/DOS-Extender - SET PROTECTED-MODE INTERRUPT VECTOR
212505 - INT 21 P - Phar Lap 386/DOS-Extender - SET REAL-MODE INTERRUPT VECTOR
212506 - INT 21 P - Phar Lap 386/DOS-Extender - SET INT TO ALWAYS GAIN CNTRL IN PR. MODE
212507 - INT 21 P - Phar Lap 386/DOS-Extender - SET REAL- & PROTECTED-MODE INT VECTORS
212508 - INT 21 P - Phar Lap 386/DOS-Extender - GET SEGMENT LINEAR BASE ADDRESS
212509 - INT 21 P - Phar Lap 386/DOS-Extender - CONVERT LINEAR TO PHYSICAL ADDRESS
212509 - INT 21 P - FlashTek X-32VM - GET SYSTEM SEGMENTS AND SELECTORS
21250A - INT 21 P - Phar Lap 386/DOS-Extender - MAP PHYSICAL MEMORY AT END OF SEGMENT
21250C - INT 21 P - Phar Lap 386/DOS-Extender - GET HARDWARE INTERRUPT VECTORS
21250D - INT 21 P - Phar Lap 386/DOS-Extender - GET REAL-MODE LINK INFORMATION
21250E - INT 21 P - Phar Lap 386/DOS-Extender - CALL REAL-MODE PROCEDURE
21250F - INT 21 P - Phar Lap 386/DOS-Extender - CONVERT PROTECTED-MODE ADDRESS TO MS-DOS
212510 - INT 21 P - Phar Lap 386/DOS-Extender - CALL REAL-MODE PROCEDURE, REGISTERS
212511 - INT 21 P - Phar Lap 386/DOS-Extender - ISSUE REAL-MODE INTERRUPT
212512 - INT 21 P - Phar Lap 386/DOS-Extender - LOAD PROGRAM FOR DEBUGGING
212513 - INT 21 P - Phar Lap 386/DOS-Extender - ALIAS SEGMENT DESCRIPTOR
212514 - INT 21 P - Phar Lap 386/DOS-Extender - CHANGE SEGMENT ATTRIBUTES
212515 - INT 21 P - Phar Lap 386/DOS-Extender - GET SEGMENT ATTRIBUTES
212516 - INT 21 P - Phar Lap 386/DOS-Extender v2.2+ - FREE ALL MEMORY OWNED BY LDT
212517 - INT 21 P - Phar Lap 386/DOS-Extender v2.1c+ - GET INFO ON DOS DATA BUFFER
212518 - INT 21 P - Phar Lap 386/DOS-Extender 2.1c+ - SPECIFY HANDLER FOR MOVED SEGMENTS
212519 - INT 21 P - Phar Lap 386/DOS-Extender VMM - GET ADDITIONAL MEMORY ERROR INFO
21251A - INT 21 P - Phar Lap 386/DOS-Extender VMM - LOCK PAGES IN MEMORY
21251B - INT 21 P - Phar Lap 386/DOS-Extender VMM - UNLOCK PAGES
21251C - INT 21 P - Phar Lap 386/DOS-Extender VMM v2.1c+ - FREE PHYSICAL MEMORY PAGES
21251D - INT 21 OP - Phar Lap 386/DOS-Extender VMM v2.1c - READ PAGE-TABLE ENTRY
21251E - INT 21 OP - Phar Lap 386/DOS-Extender VMM v2.1c - WRITE PAGE-TABLE ENTRY
21251F - INT 21 P - Phar Lap 386/DOS-Extender VMM - EXHANGE TWO PAGE-TABLE ENTRIES
212520 - INT 21 P - Phar Lap 386/DOS-Extender VMM - GET MEMORY STATISTICS
212521 - INT 21 P - Phar Lap 386/DOS-Extender VMM - LIMIT PROGRAM'S EXTENDED MEM USAGE
212522 - INT 21 P - Phar Lap 386/DOS-Ext VMM v2.2+ - SPECIFY ALTERNATE PAGE-FAULT HANDLR
212523 - INT 21 P - Phar Lap 386/DOS-Ext VMM v2.2+ - SPECIFY OUT-OF-SWAP-SPACE HANDLER
212524 - INT 21 P - Phar Lap 386/DOS-Ext VMM v2.2+ - INSTALL PAGE-REPLACEMENT HANDLERS
212525 - INT 21 P - Phar Lap 386/DOS-Extender VMM - LIMIT PROGRAM'S CONVENT'L MEM USAGE
212526 - INT 21 P - Phar Lap 386/DOS-Extender - GET CONFIGURATION INFORMATION
212527 - INT 21 P - Phar Lap 386/DOS-Extender VMM - EN/DISABLE STATE SAVE ON INTERRUPTS
212528 - INT 21 P - Phar Lap 386/DOS-Extender VMM - READ REGISTERS AFTER CTRL-C INT
212529 - INT 21 P - Phar Lap 386/DOS-Extender - LOAD FLAT MODEL .EXP or .REX FILE
21252A - INT 21 P - Phar Lap 386/DOS-Extender VMM - NEW LOAD PROGRAM FOR DEBUG
21252BBH00 - INT 21 Pu - Phar Lap 386/DOS-Extender - CREATE UNMAPPED PAGES
21252BBH01 - INT 21 Pu - Phar Lap 386/DOS-Extender - CREATE ALLOCATED PAGES
21252BBH02 - INT 21 Pu - Phar Lap 386/DOS-Extender - CREATE PHYSICAL DEVICE PAGES
21252BBH03 - INT 21 Pu - Phar Lap 386/DOS-Extender - MAP DATA FILE
21252BBH04 - INT 21 Pu - Phar Lap 386/DOS-Extender - GET PAGE TYPES
21252B - INT 21 P - Phar Lap 386/DOS-Extender - VIRTUAL MEMORY MANAGEMENT - PAGE LOCKING
21252B - INT 21 Pu - Phar Lap 386/DOS-Extender - FREE PHYSICAL PAGES
21252BBH09 - INT 21 P - Phar Lap 386/DOS-Extender v4.1 - GET PAGETABLE ENTRY/PAGE TABLE INFO
21252BBH0A - INT 21 P - Phar Lap 386/DOS-Extender v4.1 - SET PAGETABLE ENTRY/PAGE TABLE INFO
21252BBH0B - INT 21 P - Phar Lap 386/DOS-Extender v4.1+ - MAP DATA FILE AT FILE OFFSET
21252C - INT 21 P - Phar Lap 386/DOS-Ext VMM v3.0 - ADD UNMAPPED PAGES AT END OF SEGMENT
21252D - INT 21 P - Phar Lap 386/DOS-Extender VMM v2.3+ - CLOSE VMM FILE HANDLE
21252E - INT 21 P - Phar Lap 386/DOS-Extender VMM v2.3+ - GET/SET VMM PARAMETERS
21252F - INT 21 P - Phar Lap 386/DOS-Ext VMM v3.0 - WRITE RECORD TO VMM PAGE LOG FILE
212530 - INT 21 P - Phar Lap 386/DOS-Ext VMM v2.3+ - SET SIZE OF BUFFER FOR DOS CALLS
212531 - INT 21 P - Phar Lap 386/DOS-Extender VMM v3.0 - READ/WRITE LDT DESCRIPTOR
212532 - INT 21 P - Phar Lap 386/DOS-Extender - GET EXCEPTION HANDLER VECTOR
212533 - INT 21 P - Phar Lap 386/DOS-Extender - SET EXCEPTION HANDLER VECTOR
212534 - INT 21 P - Phar Lap 386/DOS-Extender v3.0+ - GET INTERRUPT FLAG
212535 - INT 21 P - Phar Lap 386/DOS-Extender v3.0+ - READ/WRITE SYSTEM REGISTERS
212536 - INT 21 P - Phar Lap 386/DOS-Ext VMM v3.0+ - MIN/MAX EXTENDED/CONV MEMORY USAGE
212537 - INT 21 P - Phar Lap 386/DOS-Ext VMM v3.0 - ALLOCATE DOS MEMORY ABOVE DOS BUFFER
212538 - INT 21 P - Phar Lap 386/DOS-Ext VMM v3.0 - READ PROTMODE REGS AFTER SFTWARE INT
212539 - INT 21 P - Phar Lap 386/DOS-Ext VMM v3.0 - GET OFFSET OF .EXP FILE HEADER
21253A - INT 21 P - Phar Lap 386/DOS-Extender v3.0+ - INSTALL MOD. SEG FAILURE HANDLER
21253B - INT 21 P - Phar Lap 386/DOS-Extender v3.0+ - JUMP TO REAL MODE CODE, NO CONTEXT
21253C - INT 21 P - Phar Lap 386/DOS-Extender VMM v3.0+ - SHRINK 386|VMM SWAP FILE
21253D - INT 21 P - Phar Lap 386/DOS-Extender v4.0+ - READ/WRITE IDT DESCRIPTOR
21253F - INT 21 Pu - Phar Lap 386/DOS-Extender v6.0+ - ALLOCATE LDT DESCRIPTOR
212540 - INT 21 Pu - Phar Lap 386/DOS-Extender v6.0+ - FORCE ALIAS OF SEGMENT
212544 - INT 21 Pu - Phar Lap 386/DOS-Extender v6.0+ - FREE DLL
212545 - INT 21 Pu - Phar Lap 386/DOS-Extender v6.0+ - GET/SET PROCEDURE ADDRESS
212546 - INT 21 Pu - Phar Lap 386/DOS-Extender v6.0+ - GET MODULE HANDLE
2125C0 - INT 21 P - Phar Lap 386/DOS-Extender - ALLOCATE MS-DOS MEMORY BLOCK
2125C1 - INT 21 P - Phar Lap 386/DOS-Extender - RELEASE MS-DOS MEMORY BLOCK
2125C2 - INT 21 P - Phar Lap 386/DOS-Extender - MODIFY MS-DOS MEMORY BLOCK
2125C3 - INT 21 P - Phar Lap 386/DOS-Extender - EXECUTE PROGRAM
2126 - INT 21 - DOS 1+ - CREATE NEW PROGRAM SEGMENT PREFIX
2127 - INT 21 - DOS 1+ - RANDOM BLOCK READ FROM FCB FILE
2128 - INT 21 - DOS 1+ - RANDOM BLOCK WRITE TO FCB FILE
2129 - INT 21 - DOS 1+ - PARSE FILENAME INTO FCB
212A - INT 21 - DOS 1+ - GET SYSTEM DATE
212B - INT 21 - DOS 1+ - SET SYSTEM DATE
212B--CX4149 - INT 21 - AI Architects - ??? - INSTALLATION CHECK
212B--CX4358 - INT 21 - Super PC-Kwik v3.20+ - INSTALLATION CHECK
212B--CX4445 - INT 21 - DESQview - INSTALLATION CHECK
212B--CX454C - INT 21 - ELRES v1.1 - INSTALLATION CHECK
212B00CX5643 - INT 21 - The Volkov Commander - GET POINTER TO LEFT PANEL DATA STRUCTURE
212B01CX5643 - INT 21 - The Volkov Commander - GET POINTER TO RIGHT PANEL DATA STRUCTURE
212B02CX5643 - INT 21 - The Volkov Commander - GET POINTER TO GLOBAL VARIABLES
212B01CX444D - INT 21 - Quarterdeck DOS-UP.SYS v2.00 - INSTALLATION CHECK
212B01CX5441 - INT 21 - TAME v2.10+ - INSTALLATION CHECK
212B16CX0643 - INT 21 - VIRUS - "Maltese Amoeba" - INSTALLATION CHECK
212B44BX4D41 - INT 21 - pcANYWHERE IV/LAN - INSTALLATION CHECK
212B--CX5643 - INT 21 - Volkov Commander - INSTALLATION CHECK
212B--CX6269 - INT 21 - WDTSR.COM - INSTALLATION CHECK
212B--CX6269 - INT 21 - bitFOSS - INSTALLATION CHECK
212B--CX6269 - INT 21 - bitFOSSI - INSTALLATION CHECK
212C - INT 21 - DOS 1+ - GET SYSTEM TIME
212C - INT 21 - VIRUS - "Anti Pode 2.0" - INSTALLATION CHECK
212C00CX534B - INT 21 - SKUDO - INSTALLATION CHECK
212C2C - INT 21 - VIRUS - "LockJaw/Proto-T" - INSTALLATION CHECK
212D - INT 21 - DOS 1+ - SET SYSTEM TIME
212D01CX7820 - INT 21 - PC-Mix - INSTALLATION CHECK
212E--DL00 - INT 21 - DOS 1+ - SET VERIFY FLAG
212F - INT 21 - DOS 2+ - GET DISK TRANSFER AREA ADDRESS
2130 - INT 21 - DOS 2+ - GET DOS VERSION
2130 - INT 21 - Phar Lap 386/DOS-Extender, Intel Code Builder - INSTALLATION CHECK
2130--DXABCD - INT 21 - VIRUS - "Possessed" - INSTALLATION CHECK
2130--SI1234 - INT 21 - VIRUS - "ANDROMEDA-758" -INSTALLATION CHECK
213000BX1234 - INT 21 - CTask 2.0+ - INSTALLATION CHECK
213000BX3000 - INT 21 - PC-MOS/386 v3.0 - INSTALLATION CHECK/GET VERSION
213000BX614A - INT 21 - VIRUS - "Jackal" - INSTALLATION CHECK
213022 - INT 21 - StopPrg v2.0 - INSTALLATION CHECK
213030BX694D - INT 21 - VIRUS - "IMTC" -INSTALLATION CHECK
213032DX1234 - INT 21 - VIRUS - "Uruguay" - INSTALLATION CHECK
2130F1 - INT 21 - VIRUS - "Dutch-555"/"Quit 1992" - INSTALLATION CHECK
2130FFCX4445 - INT 21 - DESQ??? - INSTALLATION CHECK
2131 - INT 21 - DOS 2+ - TERMINATE AND STAY RESIDENT
2132 - INT 21 - DOS 2+ - GET DOS DRIVE PARAMETER BLOCK FOR SPECIFIC DRIVE
2133 - INT 21 - DOS 2+ - EXTENDED BREAK CHECKING
213302 - INT 21 - DOS 3.x+ internal - GET AND SET EXTENDED CONTROL-BREAK CHECKING STATE
213303 - INT 21 - DOS 3.4/4.0 - GET CURRENT CPSW STATE
213304 - INT 21 - DOS 3.4/4.0 - SET CPSW STATE
213305 - INT 21 - DOS 4.0+ - GET BOOT DRIVE
213306 - INT 21 - DOS 5+ - GET TRUE VERSION NUMBER
213306 - INT 21 - CBIS network - NETWORK REDIRECTOR - ???
213307 - INT 21 - Windows95 - SET/CLEAR DOS_FLAG
21330F - INT 21 - VIRUS - "Burghofer" - INSTALLATION CHECK
213341 - INT 21 - Diet Disk v1.0 - INSTALLATION CHECK
2133DA - INT 21 - VIRUS - "CoffeeShop" - INSTALLATION CHECK
2133DB - INT 21 - VIRUS - "CoffeeShop" - GENERATE RANDOM NUMBER
2133DC - INT 21 - VIRUS - "CoffeeShop" - DISPLAY "LEGALIZE CANNABIS" GRAPHIC
2133E0 - INT 21 - VIRUS - "Oropax" - INSTALLATION CHECK
2134 - INT 21 - DOS 2+ - GET ADDRESS OF INDOS FLAG
2135 - INT 21 - DOS 2+ - GET INTERRUPT VECTOR
213501 - INT 21 P - FlashTek X-32VM - ALLOCATE PROTECTED-MODE SELECTOR
213502 - INT 21 P - FlashTek X-32VM - DEALLOCATE PROTECTED-MODE SELECTOR
213503 - INT 21 P - FlashTek X-32VM - SET SELECTOR BASE ADDRESS
213504 - INT 21 P - FlashTek X-32VM - GET SELECTOR BASE ADDRESS
213505 - INT 21 P - FlashTek X-32VM - SET SELECTOR LIMIT
21350A - INT 21 P - FlashTek X-32VM - PHYSICAL ADDRESS MAPPING
21350B - INT 21 P - FlashTek X-32VM - UPDATE AND RETURN AVAILABLE FREE MEMORY
21350C - INT 21 P - FlashTek X-32VM - ALLOCATE A BLOCK OF MEMORY
21350D - INT 21 P - FlashTek X-32VM - RESERVE BLOCK OF MEMORY FOR 32-BIT STACK
21357F - INT 21 - VIRUS - "Agiplan"/"Month 4-6" - INSTALLATION CHECK
2136 - INT 21 - DOS 2+ - GET FREE DISK SPACE
213700 - INT 21 - DOS 2+ - "SWITCHAR" - GET SWITCH CHARACTER
213701 - INT 21 - DOS 2+ - "SWITCHAR" - SET SWITCH CHARACTER
2137 - INT 21 - DOS 2.x and 3.3+ only - "AVAILDEV" - SPECIFY \DEV\ PREFIX USE
2137A0BX6A6D - INT 21 - XPACK v1.52+ - TSR INSTALLATION CHECK
2137A1BX6A6D - INT 21 - XPACK v1.52+ - UNINSTALL
2137A2BX6A6D - INT 21 - XPACK v1.52+ - GET TSR STATUS
2137A3BX6A6D - INT 21 - XPACK v1.52+ - SET TSR STATUS
2137A6BX6A6D - INT 21 - XPACK v1.65 - GET TEMPORARY DIRECTORY NAME
2137A7BX6A6D - INT 21 - XPACK v1.65 - SET TEMPORARY DIRECTORY NAME
2137D0BX899D - INT 21 - DIET v1.43e - TSR INSTALLATION CHECK
2137D1BX899D - INT 21 - DIET v1.43e - GET DIET.EXE RESIDENT SEGMENT
2137D2BX899D - INT 21 - DIET v1.43e - GET TSR CONTROL FLAGS
2137D3BX899D - INT 21 - DIET v1.43e - SET TSR CONTROL FLAGS
2137D4BX899D - INT 21 - DIET v1.43e - GET TSR OPTIONS
2137D5BX899D - INT 21 - DIET v1.43e - SET TSR OPTIONS
2137D6BX899D - INT 21 - DIET v1.43e - GET TEMPORARY DIRECTORY NAMES
2137D7BX899D - INT 21 - DIET v1.43e - SET TEMPORARY DIRECTORY NAMES
2137DCBX899D - INT 21 - DIET v1.43e - SET ADDRESS OF EXTERNAL PROCEDURE
2137DDBX899D - INT 21 - DIET v1.43e - RELEASE EXTERNAL PROCEDURE
2137DEBX899D - INT 21 - DIET v1.43e - READ EMS STATUS
2137DFBX899D - INT 21 - DIET v1.43e - UNINSTALL TSR
2138 - INT 21 - DOS 2+ - GET COUNTRY-SPECIFIC INFORMATION
2138--DXFFFF - INT 21 - DOS 3.0+ - SET COUNTRY CODE
2139 - INT 21 - DOS 2+ - "MKDIR" - CREATE SUBDIRECTORY
213A - INT 21 - DOS 2+ - "RMDIR" - REMOVE SUBDIRECTORY
213B - INT 21 - DOS 2+ - "CHDIR" - SET CURRENT DIRECTORY
213C - INT 21 - DOS 2+ - "CREAT" - CREATE OR TRUNCATE FILE
213D - INT 21 - DOS 2+ - "OPEN" - OPEN EXISTING FILE
213D76 - INT 21 - VIRUS - "GT-SPOOF" -INSTALLATION CHECK
213DFF - INT 21 - VIRUS - "JD-448" - INSTALLATION CHECK
213E - INT 21 - DOS 2+ - "CLOSE" - CLOSE FILE
213F - INT 21 - DOS 2+ - "READ" - READ FROM FILE OR DEVICE
213F - INT 21 - Turbo Debug HARDWARE BREAKPOINTS - READ STATUS BLOCK
213F - INT 21 - PC/TCP IPCUST.SYS - READ CONFIGURATION DATA
213F - INT 21 - WORKGRP.SYS - GET ENTRY POINT
213F - INT 21 - BW-TCP - GET DRIVER INFO
213F - INT 21 - Trusted Access - NB.SYS - GET STATE
213F - INT 21 U - IFSHLP.SYS - GET ENTRY POINT
213F--BXFEB0 - INT 21 - VIRUS - "KYZ/LieWait" - INSTALLATION CHECK
2140 - INT 21 - DOS 2+ - "WRITE" - WRITE TO FILE OR DEVICE
2140 - INT 21 - Turbo Debug HARDWARE BREAKPOINTS - SEND CMD TO HARDWARE BRKPNT DRIVER
2140 - INT 21 - PC/TCP IPCUST.SYS - WRITE CONFIGURATION DATA
2140 - INT 21 U - Trusted Access - NB.SYS - SET STATE
214000BX0002 - INT 21 - FARTBELL.EXE - INSTALLATION CHECK
214001BX0002 - INT 21 - FARTBELL.EXE - FORCE NOISE
2141 - INT 21 - DOS 2+ - "UNLINK" - DELETE FILE
214101DXFFFE - INT 21 - SoftLogic Data Guardian - ???
2142 - INT 21 - DOS 2+ - "LSEEK" - SET CURRENT FILE POSITION
214203 - INT 21 - VIRUS - "Shake" - INSTALLATION CHECK
214243 - INT 21 - VIRUS - "Invader" - INSTALLATION CHECK
214300 - INT 21 - DOS 2+ - GET FILE ATTRIBUTES
214301 - INT 21 - DOS 2+ - "CHMOD" - SET FILE ATTRIBUTES
214302 - INT 21 - MS-DOS 7 - GET COMPRESSED FILE SIZE
214302 - INT 21 - DR DOS 3.41+ internal - GET ACCESS RIGHTS
214303 - INT 21 - DR DOS 3.41+ internal - SET ACCESS RIGHTS AND PASSWORD
214304 - INT 21 U - DR DOS 5.0-6.0 internal - GET ENCRYPTED PASSWORD
214305 - INT 21 U - DR DOS 5.0-6.0 internal - SET EXTENDED FILE ATTRIBUTES
214306 - INT 21 O - DR DOS 6.0 - GET FILE OWNER
214307 - INT 21 O - DR DOS 6.0 - SET FILE OWNER
214310 - INT 21 - Banyan VINES 2.1+ - GET EXTENDED FILE ATTRIBUTES
214311 - INT 21 - Banyan VINES 2.1+ - SET EXTENDED FILE ATTRIBUTES
214321BX0000 - INT 21 - Q87, Q387 - INSTALLATION CHECK
214321BX0001 - INT 21 - Q87, Q387 - ENABLE EMULATOR
214321BX0002 - INT 21 - Q87, Q387 - DISABLE EMULATOR
214380 - INT 21 - Novell DOS 7 - UNDELETE PENDING DELETE FILE
214381 - INT 21 - Novell DOS 7 - PURGE PENDING DELETE FILE
214382 - INT 21 - DR-DOS >7.03 - RESERVED
2143FFBP5053 - INT 21 - MS-DOS 7.20 (Win98) - EXTENDED-LENGTH FILENAME OPERATIONS
Section -
Top

Table of Contents by Category

! - document info

- - uncategorized

D - DOS kernel

E - DOS extenders

G - debuggers/debugging tools

K - keyboard enhancers

N - network

O - other operating systems,

Q - DESQview/TopView and Quarterdeck programs,

R - remote control/file access

S - serial I/O

T - DOS-based task switchers/multitaskers

U - resident utilities

W - MS Windows,

c - caches/spoolers,

j - joke programs,

k - file/disk compression,

l - shells/command interpreters,

m - memory management,

u - emulators,

v - virus/antivirus,

y - security

INT 20 - Minix - SEND/RECEIVE MESSAGE
	AX = process ID of other process
	BX -> message
	CX = operation (1 send, 2 receive, 3 send&receive)
Program: Minix is a Version 7 Unix-compatible operating system by Andrew
	  Tanenbaum
Note:	the message contains the system call number (numbered as in V7
	  Unix(tm)) and the call parameters

INT 20 - DOS 1+ - TERMINATE PROGRAM
	CS = PSP segment
Return: never
Notes:	(see INT 21/AH=00h)
	this function sets the program's return code (ERRORLEVEL) to 00h
SeeAlso: INT 21/AH=00h,INT 21/AH=4Ch

INT 20 - COMTROL HOSTESS i/ISA DEBUGGER - INVOKE FIRMWARE DEBUGGER
	???
Return: ???
SeeAlso: INT 21"COMTROL"

INT 20 P - Microsoft Windows - VMM - VxD SERVICES
	VxD = 0001h
Note:	the desired VxD and service number are identified by the data
	  immediately following the INT 20 instruction, as in:
		INT	20h
		DW	service number
		DW	VxD identifier
SeeAlso: INT 2F/AX=1684h"DEVICE API",INT 30"Windows",#01265,#01340

(Table 01265)
Values for VMM (VxD ID 0001h) service number:
 0000h	get version
 0001h	get current VM handle
 0002h	test current VM handle
 0003h	get system VM handle
 0004h	test system VM handle
 0005h	validate VM handle
 0006h	get VMM reenter count
 0007h	begin reentrant execution
 0008h	end reentrant execution
 0009h	install V86 breakpoint
 000Ah	remove V86 breakpoint
 000Bh	allocate V86 callback
 000Ch	allocation PM callback
 000Dh	call when VM returns
 000Eh	schedule global event
 000Fh	schedule VM event
 0010h	call global event
 0011h	call VM event
 0012h	cancel global event
 0013h	cancel VM event
 0014h	call priority VM event
 0015h	cancel priority VM event
 0016h	get NMI handler address
 0017h	set NMI handler address
 0018h	hook NMI event
 0019h	call when VM interrupts enabled
 001Ah	enable VM interrupts
 001Bh	disable VM interrupts
 001Ch	map flat
 001Dh	map linear to VM address
 001Eh	adjust execution priority
 001Fh	begin critical section
 0020h	end critical section
 0021h	end critical section and suspend
 0022h	claim critical section
 0023h	release critical section
 0024h	call when not critical
 0025h	create semaphore
 0026h	destroy semaphore
 0027h	wait on semaphore
 0028h	signal semaphore
 0029h	get critical section status
 002Ah	call when task switched
 002Bh	suspend VM
 002Ch	resume VM
 002Dh	no-fail resume VM
 002Eh	nuke VM
 002Fh	crash current VM
 0030h	get execution focus
 0031h	set execution focus
 0032h	get time slice priority
 0033h	set time slice priority
 0034h	get time slice granularity
 0035h	set time slice granularity
 0036h	get time slice information
 0037h	adjust execution time
 0038h	release time slice
 0039h	wake up VM
 003Ah	call when idle
 003Bh	get next VM handle
 003Ch	set global timeout
 003Dh	set VM timeout
 003Eh	cancel timeout
 003Fh	get system time
	Return: EAX = time in milliseconds that Windows has been running
 0040h	get VM execution time
 0041h	hook V86 interrupt chain
 0042h	get V86 interrupt vector
 0043h	set V86 interrupt vector
 0044h	get PM interrupt vector
 0045h	set PM interrupt vector
 0046h	simulate interrupt
 0047h	simulate IRET
 0048h	simulate far call
 0049h	simulate far jump
 004Ah	simulate far RET
 004Bh	simulate far RET N
 004Ch	build interrupt stack frame
 004Dh	simulate push
 004Eh	simulate pop
 004Fh	_HeapAllocate
 0050h	_HeapReAllocate
 0051h	_HeapFree
 0052h	_HeapGetSize
 0053h	_PageAllocate
 0054h	_PageReAllocate
 0055h	_PageFree
 0056h	_PageLock
 0057h	_PageUnLock
 0058h	_PageGetSizeAddr
 0059h	_PageGetAllocInfo
 005Ah	_GetFreePageCount
 005Bh	_GetSysPageCount
 005Ch	_GetVMPgCount
 005Dh	_MapIntoV86
 005Eh	_PhysIntoV86
 005Fh	_TestGlobalV86Mem
 0060h	_ModifyPageBits
 0061h	copy page table
 0062h	map linear into V86
 0063h	linear page lock
 0064h	linear page unlock
 0065h	_SetResetV86Pageabl
 0066h	_GetV86PageableArray
 0067h	_PageCheckLinRange
 0068h	page out dirty pages
 0069h	discard pages
 006Ah	_GetNulPageHandle
 006Bh	get first V86 page
 006Ch	map physical address to linear address
 006Dh	_GetAppFlatDSAlias
 006Eh	_SelectorMapFlat
 006Fh	_GetDemandPageInfo
 0070h	_GetSetPageOutCount
 0071h	hook V86 page
 0072h	assign device V86 pages
 0073h	deassign device V86 pages
 0074h	get array of V86 pages for device
 0075h	_SetNULPageAddr
 0076h	allocate GDT selector
 0077h	free GDT selector
 0078h	allocate LDT selector
 0079h	free LDT selector
 007Ah	_BuildDescriptorDWORDs
 007Bh	get descriptor
 007Ch	set descriptor
 007Dh	toggle HMA
 007Eh	get fault hook addresses
 007Fh	hook V86 fault
 0080h	hook PM fault
 0081h	hook VMM fault
 0082h	begin nested V86 execution
 0083h	begin nested execution
 0084h	execute V86-mode interrupt
 0085h	resume execution
 0086h	end nested execution
 0087h	allocate PM application callback area
 0088h	get current PM application callback area
 0089h	set V86 execution mode
 008Ah	set PM execution mode
 008Bh	begin using locked PM stack
 008Ch	end using locked PM stack
 008Dh	save client state
 008Eh	restore client state
 008Fh	execute VxD interrupt
	STACK:	WORD	interrupt number
		other registers as required by interrupt call
	Return:	registers as returned by interrupt call
 0090h	hook device service
	EAX = service ID (high word = VxD ID, low = service number)
	ESI -> new handler
 0091h	hook device V86 API
 0092h	hook device PM API
 0093h	system control (see also #02657)
 0094h	simulate I/O
 0095h	install multiple I/O handlers
 0096h	install I/O handler
	DX = I/O port address
	ESI -> handler to call when I/O access attempted???
 0097h	enable global trapping
	DX = I/O port address
 0098h	enable local trapping
	DX = I/O port address
 0099h	disable global trapping
	DX = I/O port address
 009Ah	disable local trapping
	DX = I/O port address
 009Bh	create list
 009Ch	destroy list
 009Dh	allocate list
 009Eh	attach list
 009Fh	attach list tail
 00A0h	insert into list
 00A1h	remove from list
 00A2h	deallocate list
 00A3h	get first item in list
 00A4h	get next item in list
 00A5h	remove first item in list
 00A6h	add instance item
 00A7h	allocate device callback area
 00A8h	allocate global V86 data area
 00A9h	allocate temporary V86 data area
 00AAh	free temporary V86 data area
 00ABh	get decimal integer from profile
 00ACh	convert decimal string to integer
 00ADh	get fixed-point number from profile
 00AEh	convert fixed-point string
 00AFh	get hex integer from profile
 00B0h	convert hex string to integer
 00B1h	get boolean value from profile
 00B2h	convert boolean string
 00B3h	get string from profile
 00B4h	get next string from profile
 00B5h	get environment string
 00B6h	get exec path
 00B7h	get configuration directory
 00B8h	open file
 00B9h	get PSP segment
 00BAh	get DOS vectors
 00BBh	get machine information
 00BCh	get/set HMA information
 00BDh	set system exit code
 00BEh	fatal error handler
 00BFh	fatal memory error
 00C0h	update system clock
 00C1h	test if debugger installed
 00C2h	output debugger string
 00C3h	output debugger character
 00C4h	input debugger character
 00C5h	debugger convert hex to binary
 00C6h	debugger convert hex to decimal
 00C7h	debugger test if valid handle
 00C8h	validate client pointer
 00C9h	test reentry
 00CAh	queue debugger string
 00CBh	log procedure call
 00CCh	debugger test current VM
 00CDh	get PM interrupt type
 00CEh	set PM interrupt type
 00CFh	get last updated system time
 00D0h	get last updated VM execution time
 00D1h	test if double-byte character-set lead byte
 00D2h	_AddFreePhysPage
 00D3h	_PageResetHandlePAddr
 00D4h	_SetLastV86Page
 00D5h	_GetLastV86Page
 00D6h	_MapFreePhysReg
 00D7h	_UnmapFreePhysReg
 00D8h	_XchgFreePhysReg
 00D9h	_SetFreePhysRegCalBk
 00DAh	get next arena (MCB)
 00DBh	get name of ugly TSR
 00DCh	get debug options
 00DDh	set physical HMA alias
 00DEh	_GetGlblRng0V86IntBase
 00DFh	add global V86 data area
 00E0h	get/set detailed VM error
 00E1h	Is_Debug_Chr
 00E2h	clear monochrome screen
 00E3h	output character to mono screen
 00E4h	output string to mono screen
 00E5h	set current position on mono screen
 00E6h	get current position on mono screen
 00E7h	get character from mono screen
 00E8h	locate byte in ROM
 00E9h	hook invalid page fault
 00EAh	unhook invalid page fault
 00EBh	set delete on exit file
 00ECh	close VM
 00EDh	"Enable_Touch_1st_Meg"
 00EEh	"Disable_Touch_1st_Meg"
 00EFh	install exception handler
 00F0h	remove exception handler
 00F1h	"Get_Crit_Status_No_Block"
 00F2h	"_Schedule_VM_RTI_Event"
 00F3h	"_Trace_Out_Service"
 00F4h	"_Debug_Out_Service"
 00F5h	"_Debug_Flags_Service"
 00F6h	VMM add import module name
 00F7h	VMM Add DDB
 00F8h	VMM Remove DDB
 00F9h	get thread time slice priority
 00FAh	set thread time slice priority
 00FBh	schedule thread event
 00FCh	cancel thread event
 00FDh	set thread timeout
 00FEh	set asynchronous timeout
 00FFh	"_AllocatreThreadDataSlot"
 0100h	"_FreeThreadDataSlot"
 0101h	create Mutex
 0102h	destroy Mutex
 0103h	get Mutex owner
 0104h	call when thread switched
 0105h	create thread
 0106h	start thread
 0107h	terminate thread
 0108h	get current thread handle
 0109h	test current thread handle
 010Ah	"Get_Sys_Thread_Handle"
 010Bh	"Test_Sys_Thread_Handle"
 010Ch	"Validate_Thread_Handle"
 010Dh	"Get_Initial_Thread_Handle"
 010Eh	"Test_Initial_Thread_Handle"
 010Fh	"Debug_Test_Valid_Thread_Handle"
 0110h	"Debug_Test_Cur_Thread"
 0111h	"VMM_GetSystemInitState"
 0112h	"Cancel_Call_When_Thread_Switched"
 0113h	"Get_Next_Thread_Handle"
 0114h	"Adjust_Thread_Exec_Priority"
 0115h	"_Deallocate_Device_CB_Area"
 0116h	"Remove_IO_Handler"
 0117h	"Remove_Mult_IO_Handlers"
 0118h	unhook V86 interrupt chain
 0119h	unhook V86 fault handler
 011Ah	unhook PM fault handler
 011Bh	unhook VMM fault handler
 011Ch	unhook device service
 011Dh	"_PageReserve"
 011Eh	"_PageCommit"
 011Fh	"_PageDecommit"
 0120h	"_PagerRegister"
 0121h	"_PagerQuery"
 0122h	"_PagerDeregister"
 0123h	"_ContextCreate"
 0124h	"_ContextDestroy"
 0125h	"_PageAttach"
 0126h	"_PageFlush"
 0127h	"_SignalID"
 0128h	"_PageCommitPhys"
 0129h	"_Register_Win32_Services"
 012Ah	"Cancel_Call_When_Not_Critical"
 012Bh	"Cancel_Call_When_Idle"
 012Ch	"Cancel_Call_When_Task_Switched"
 012Dh	"_Debug_Printf_Service"
 012Eh	enter Mutex
 012Fh	leave Mutex
 0130h	simulate VM I/O
 0131h	"Signal_Semaphore_No_Switch"
 0132h	"_MMSwitchContext"
 0133h	"_MMModifyPermissions"
 0134h	"_MMQuery"
 0135h	"_EnterMustComplete"
 0136h	"_LeaveMustComplete"
 0137h	"_ResumeExecMustComplete"
 0138h	get thread termination status
 0139h	"_GetInstanceInfo"
 013Ah	"_ExecIntMustComplete"
 013Bh	"_ExecVxDIntMustComplete"
 013Ch	begin V86 serialization
 013Dh	unhook V86 page
 013Eh	"VMM_GetVxDLocationList"
 013Fh	"VMM_GetDDBList" get start of VxD chain
	(see also #02657 at INT 2F/AX=1684h/BX=0017h)
 0140h	unhook NMI event
 0141h	"Get_Instanced_V86_Int_Vector"
 0142h	get or set real DOS PSP
 0143h	call priority thread event
 0144h	"Get_System_Time_Address"
 0145h	"Get_Crit_Status_Thread"
 0146h	"Get_DDB"
 0147h	"Directed_Sys_Control"
 0148h	"_RegOpenKey"
 0149h	"_RegCloseKey"
 014Ah	"_RegCreateKey"
 014Bh	"_RegDeleteKey"
 014Ch	"_RegEnumKey"
 014Dh	"_RegQueryValue"
 014Eh	"_RegSetValue"
 014Fh	"_RegDeleteValue"
 0150h	"_RegEnumValue"
 0151h	"_RegQueryValueEx"
 0152h	"_RegSetValueEx"
 0153h	"_CallRing3"
 0154h	"Exec_PM_Int"
 0155h	"_RegFlushKey"
 0156h	"_PageCommitContig"
 0157h	"_GetCurrentContext"
 0158h	"_LocalizeSprintf"
 0159h	"_LocalizeStackSprintf"
 015Ah	"Call_Restricted_Event"
 015Bh	"Cancel_Restricted_Event"
 015Ch	"Register_PEF_Provider"
 015Dh	"_GetPhysPageInfo"
 015Eh	"_RegQueryInfoKey"
 015Fh	"MemArb_Reserve_Pages"
 0160h	"Time_Slice_Sys_VM_Idle"
 0161h	"Time_Slice_Sleep"
 0162h	"Boost_With_Decay"
 0163h	"Set_Inversion_Pri"
 0164h	"Reset_Inversion_Pri"
 0165h	"Release_Inversion_Pri"
 0166h	"Get_Thread_Win32_Pri"
 0167h	"Set_Thread_Win32_Pri"
 0168h	"Set_Thread_Static_Boost"
 0169h	"Set_VM_Static_Boost"
 016Ah	"Release_Inversion_Pri_ID"
 016Bh	"Attach_Thread_To_Group"
 016Ch	"Detach_Thread_From_Group"
 016Dh	"Set_Group_Static_Boost"
 016Eh	"_GetRegistryPath"
 016Fh	"_GetRegistryKey"
 0170h	"_CleanupNestedExec"
 0171h	"_RegRemapPreDefKey"
 0172h	"End_V86_Serialization"
 0173h	"_Assert_Range"
 0174h	"_Sprintf"
 0175h	"_PageChangePager"
 0176h	"_RegCreateDynKey"
 0177h	"RegQMulti"
 0178h	"Boost_Thread_With_VM"
 0179h	"Get_Boot_Flags"
 017Ah	"Set_Boot_Flags"
 017Bh	"_lstrcpyn"
 017Ch	"_lstrlen"
 017Dh	"_lmemcpy"
 017Eh	"_GetVxDName"
 017Fh	"Force_Mutexes_Free"
 0180h	"Restore_Forced_Mutexes"
 0181h	"_AddReclaimableItem"
 0182h	"_SetReclaimableItem"
 0183h	"_EnumReclaimableItem"
 0184h	"Time_Slice_Wake_Sys_VM"
 0185h	"VMM_Replace_Global_Environment"
 0186h	"Begin_Non_Serial_Nest_V86_Exec"
 0187h	"Get_Nest_Exec_Status"
 0188h	"Open_Boot_Log"
 0189h	"Write_Boot_Log"
 018Ah	"Close_Boot_Log"
 018Bh	"EnableDisable_Boot_Log"
 018Ch	"_Call_On_My_Stack"
 018Dh	"Get_Inst_V86_Int_Vec_Base"
 018Eh	"_lstrcmpi"
 018Fh	"_strupr"
 0190h	"Log_Fault_Call_Out"
 0191h	"_AtEventTime"
 0191h	...last service for Windows95 SP1
 811Ch	unhook device service??? (called by KEYREMAP.VXD)
	EAX = service ID (high word = VxD ID, low = service number)
	ESI -> handler
SeeAlso: #01266,#01267,INT 2F/AX=1684h/BX=0001h

INT 20 P - Microsoft Windows - DEBUG - VxD SERVICES
	VxD = 0002h
Note:	the desired VxD and service number are identified by the data
	  immediately following the INT 20 instruction, as in:
		INT	20h
		DW	service number
		DW	VxD identifier
SeeAlso: INT 2F/AX=1684h"DEVICE API",INT 30"Windows",#01266,#01340

(Table 01266)
Values for DEBUG (VxD ID 0002h) service number:
 0000h	get version
 0001h	"DEBUG_Fault"
 0002h	"DEBUG_CheckFault"
 0003h	"_DEBUG_LoadSyms"
SeeAlso: #01265,#01267

INT 20 P - Microsoft Windows - VPICD - VxD SERVICES
	VxD = 0003h
Note:	the desired VxD and service number are identified by the data
	  immediately following the INT 20 instruction, as in:
		INT	20h
		DW	service number
		DW	VxD identifier
SeeAlso: INT 2F/AX=1684h"DEVICE API",INT 30"Windows",#01267,#01340

(Table 01267)
Values for VPICD (VxD ID 0003h) service number:
 0000h	get version
 0001h	virtualize IRQ
 0002h	set interrupt request
 0003h	clear interrupt request
 0004h	physical EOI
 0005h	get complete status
 0006h	get status
 0007h	test physical request
 0008h	physically mask
 0009h	physically unmask
 000Ah	set automatic masking
 000Bh	get IRQ complete status
 000Ch	convert handle to IRQ
 000Dh	convert IRQ to interrupt
 000Eh	convert interrupt to IRQ
 000Fh	call on hardware interrupt
 0010h	force default owner
 0011h	force default behavior
 0012h	"VPICD_Auto_Mask_At_Inst_Swap"
 0013h	"VPICD_Begin_Inst_Page_Swap"
 0014h	"VPICD_End_Inst_Page_Swap"
 0015h	"VPICD_Virtual_EOI"
 0016h	"VPICD_Get_Virtualization_Count"
 0017h	"VPICD_Post_Sys_Critical_Init"
 0018h	"VPICD_VM_SlavePIC_Mask_Change"
SeeAlso: #01265,#01268,INT 2F/AX=1684h/BX=0003h

INT 20 P - Microsoft Windows - VDMAD - VxD SERVICES
	VxD = 0004h
Note:	the desired VxD and service number are identified by the data
	  immediately following the INT 20 instruction, as in:
		INT	20h
		DW	service number
		DW	VxD identifier
SeeAlso: INT 2F/AX=1684h"DEVICE API",INT 30"Windows",#01265,#01340

(Table 01268)
Values for VDMAD (VxD ID 0004h) service number:
 0000h	get version
 0001h	virtualize channel
 0002h	get region information
 0003h	set region information
 0004h	get virtual state
 0005h	set virtual state
 0006h	set physical state
 0007h	mask channel
 0008h	unmask channel
 0009h	lock DMA region
 000Ah	unlock DMA region
 000Bh	scatter lock
 000Ch	scatter unlock
 000Dh	reserve buffer space
 000Eh	request buffer
 000Fh	release buffer
 0010h	copy to buffer
 0011h	copy from buffer
 0012h	default handler
 0013h	disable translation
 0014h	enable translation
 0015h	get EISA address mode
 0016h	set EISA address mode
 0017h	unlock DMA region (ND)
 0018h	"VDMAD_Phys_Mask_Channel"
 0019h	"VDMAD_Phys_Unmask_Channel"
 001Ah	"VDMAD_Unvirtualize_Channel"
 001Bh	"VDMAD_Set_IO_Address"
 001Ch	"VDMAD_Get_Phys_Count"
 001Dh	"VDMAD_Get_Phys_Status"
 001Eh	"VDMAD_Get_Max_Phys_Page"
 001Fh	"VDMAD_Set_Channel_Callbacks"
 0020h	"VDMAD_Get_Virt_Count"
 0021h	"VDMAD_Set_Virt_Count"
 0021h	...last service for Windows95 SP1
SeeAlso: #01267,#02646,#02683 at INT 2F/AX=1684h/BX=0444h

INT 20 P - Microsoft Windows - VTD - VxD SERVICES
	VxD = 0005h
Note:	the desired VxD and service number are identified by the data
	  immediately following the INT 20 instruction, as in:
		INT	20h
		DW	service number
		DW	VxD identifier
SeeAlso: INT 2F/AX=1684h"DEVICE API",INT 30"Windows",#01265,#01340

(Table 01269)
Values for VTD (VxD ID 0005h) service number:
 0000h	get version
 0001h	update system clock
 0002h	get interrupt period
 0003h	begin minimum interrupt period
 0004h	end minimum interrupt period
 0005h	disable trapping
 0006h	enable trapping
 0007h	get real time
	Return: EDX:EAX = time in 840ns units since Windows was started
 0008h	"VTD_Get_Date_And_Time"
 0009h	"VTD_Adjust_VM_Count"
 000Ah	"VTD_Delay"
SeeAlso: #02646 at INT 2F/AX=1684h/BX=0005h

INT 20 P - Microsoft Windows - V86MMGR - VxD SERVICES
	VxD = 0006h
Note:	the desired VxD and service number are identified by the data
	  immediately following the INT 20 instruction, as in:
		INT	20h
		DW	service number
		DW	VxD identifier
SeeAlso: INT 2F/AX=1684h"DEVICE API",INT 30"Windows",#01265,#01340

(Table 01270)
Values for V86MMGR (VxD ID 0006h) service number:
 00h	get version
 01h	allocate V86 pages
 02h	set EMS and XMS limits
 03h	get EMS and XMS limits
 04h	set mapping information
 05h	get mapping information
 06h	Xlat API
 07h	load client pointer
 08h	allocate buffer
 09h	free buffer
 0Ah	get Xlat buffer state
 0Bh	set Xlat buffer state
 0Ch	get VM flat selector
 0Dh	map pages
 0Eh	free page map region
 0Fh	_LocalGlobalReg
 10h	get page status
 11h	set local A20
 12h	reset base pages
 13h	set available mapped pages
 14h	"V86MMGR_NoUMBInitCalls"
 15h	"V86MMGR_Get_EMS_XMS_Avail"
 16h	"V86MMGR_Toggle_HMA"
	EAX = ???
 17h	"V86MMGR_Dev_Init"
 18h	"V86MMGR_Alloc_UM_Page"
SeeAlso: #02646,#01271,INT 2F/AX=1684h"DEVICE API"

INT 20 P - Microsoft Windows - PageSwap - VxD SERVICES
	VxD = 0007h
Note:	the desired VxD and service number are identified by the data
	  immediately following the INT 20 instruction, as in:
		INT	20h
		DW	service number
		DW	VxD identifier
SeeAlso: INT 2F/AX=1684h"DEVICE API",INT 30"Windows",#01265,#01340

(Table 01271)
Values for PageSwap (VxD ID 0007h) service number:
 00h	get version
 01h	test create
 02h	create swap file
 03h	destroy swap file
 04h	in
 05h	out
 06h	test if I/O valid
 07h	"Read_Or_Write"
 08h	"Grow_File"
 09h	"Init_File"
SeeAlso: #01270,#01272,#01273,#02648

INT 20 P - Microsoft Windows - REBOOT - VxD SERVICES
	VxD = 0009h
Note:	the desired VxD and service number are identified by the data
	  immediately following the INT 20 instruction, as in:
		INT	20h
		DW	service number
		DW	VxD identifier
SeeAlso: INT 2F/AX=1684h"DEVICE API",INT 30"Windows",#01265,#01340

(Table 01272)
Values for REBOOT (VxD ID 0009h) service number:
 00h	get REBOOT version???
 01h	???
 02h	???
 03h	...last service for Windows95 SP1
SeeAlso: #01271,#01273,#02642

INT 20 P - Microsoft Windows - VDD - VxD SERVICES
	VxD = 000Ah
Note:	the desired VxD and service number are identified by the data
	  immediately following the INT 20 instruction, as in:
		INT	20h
		DW	service number
		DW	VxD identifier
SeeAlso: INT 2F/AX=1684h"DEVICE API",INT 30"Windows",#01265,#01340

(Table 01273)
Values for VDD (VxD ID 000Ah) service number:
 00h	get version
 01h	PIF state
 02h	get GrabRtn
 03h	hide cursor
 04h	set VM type
 05h	get ModTime
 06h	set HCurTrk
 07h	message clear screen
 08h	message foreground color
 09h	message background color
 0Ah	message output text
 0Bh	message set cursor position
 0Ch	query access
 0Dh	"VDD_Check_Update_Soon"
 0Eh	"VDD_Get_Mini_Dispatch_Table"
 0Fh	"VDD_Register_Virtual_Port"
	DX = base I/O port number
	CL = number of contiguous ports???
 10h	"VDD_Get_VM_Info"
 11h	"VDD_Get_Special_VM_IDs"
	Return: ESI = ???
		EDI = ???
 12h	"VDD_Register_Extra_Screen_Selector"
 13h	"VDD_Takeover_VGA_Port"
	DX = VGA I/O port number (03C2h, etc.)
	ECX -> routine to call on I/O access
	Return: ECX -> previous handler (to be jumped to at end of new handler)
 14h	???
 15h	???
 16h	...last service for Windows95 SP1
SeeAlso: #01272,#01274,#02648

INT 20 P - Microsoft Windows - VSD - VxD SERVICES
	VxD = 000Bh
Note:	the desired VxD and service number are identified by the data
	  immediately following the INT 20 instruction, as in:
		INT	20h
		DW	service number
		DW	VxD identifier
SeeAlso: INT 2F/AX=1684h"DEVICE API",INT 30"Windows",#01265,#01340

(Table 01274)
Values for VSD (VxD ID 000Bh) service number:
 00h	get version
 01h	bell
 02h	sound on
 03h	"VSD_TakeSoundPort"
SeeAlso: #01273,#01275

INT 20 P - Microsoft Windows - VMD / VMOUSE - VxD SERVICES
	VxD = 000Ch
Note:	the desired VxD and service number are identified by the data
	  immediately following the INT 20 instruction, as in:
		INT	20h
		DW	service number
		DW	VxD identifier
SeeAlso: INT 2F/AX=1684h"DEVICE API",INT 30"Windows",#01265,#01340

(Table 01275)
Values for VMD / VMOUSE (VxD ID 000Ch) service number:
 0000h	get version
 0001h	set mouse type
 0002h	get mouse owner
 0003h	"VMOUSE_Post_Pointer_Message"
 0004h	"VMOUSE_Set_Cursor_Proc"
 0005h	"VMOUSE_Call_Cursor_Proc"
 0006h	"VMOUSE_Set_Mouse_Data~Get_Mouse_Data"
 0007h	"VMOUSE_Manipulate_Pointer_Message"
 0008h	"VMOUSE_Set_Middle_Button"
 0009h	"VMD_Set_Middle_Button"
 000Ah	"VMD_Enable_Disable_Mouse_Events"
 000Bh	"VMD_Post_Absolute_Pointer_Message"
	...last service for Windows95 SP1
SeeAlso: #01274,#01276,INT 2F/AX=1684h/BX=000Ch

INT 20 P - Microsoft Windows - VKD - VxD SERVICES
	VxD = 000Dh
Note:	the desired VxD and service number are identified by the data
	  immediately following the INT 20 instruction, as in:
		INT	20h
		DW	service number
		DW	VxD identifier
SeeAlso: INT 2F/AX=1684h"DEVICE API",INT 30"Windows",#01265,#01340

(Table 01276)
Values for VKD (VxD ID 000Dh) service number:
 0000h	get version
 0001h	define hotkey
 0002h	remove hotkey
 0003h	locally enable hotkey
 0004h	locally disable hotkey
 0005h	reflect hotkey
 0006h	cancel hotkey state
 0007h	force keys
 0008h	get keyboard owner
 0009h	define paste mode
 000Ah	start pasting
 000Bh	cancel paste
 000Ch	get message key
 000Dh	peek message key
 000Eh	flush message key queue
 000Fh	"VKD_Enable_Keyboard"
 0010h	"VKD_Disable_Keyboard"
 0011h	"VKD_Get_Shift_State"
 0012h	"VKD_Filter_Keyboard_Input"
 0013h	"VKD_Put_Byte"
 0014h	"VKD_Set_Shift_State"
	...last service for Windows95 SP1
SeeAlso: #01275,#01277

INT 20 P - Microsoft Windows - VCD - VxD SERVICES
	VxD = 000Eh
Note:	the desired VxD and service number are identified by the data
	  immediately following the INT 20 instruction, as in:
		INT	20h
		DW	service number
		DW	VxD identifier
SeeAlso: INT 2F/AX=1684h"DEVICE API",INT 30"Windows",#01265,#01340

(Table 01277)
Values for VCD (VxD ID 000Eh) service number:
 0000h	get version
 0001h	set port global
 0002h	get focus
 0003h	virtualize port
 0004h	"VCD_Acquire_Port"
 0005h	"VCD_Free_Port"
 0006h	"VCD_Acquire_Port_Windows_Style"
 0007h	"VCD_Free_Port_Windows_Style"
 0008h	"VCD_Steal_Port_Windows_Style"
 0009h	"VCD_Find_COM_Index"
 000Ah	"VCD_Set_Port_Global_Special"
 000Bh	"VCD_Virtualize_Port_Dynamic"
 000Ch	"VCD_Unvirtualize_Port_Dynamic"
	...last service for Windows95 SP1
SeeAlso: #01276,#01278

INT 20 P - Microsoft Windows - BlockDev / IOS - VxD SERVICES
	VxD = 0010h
Note:	the desired VxD and service number are identified by the data
	  immediately following the INT 20 instruction, as in:
		INT	20h
		DW	service number
		DW	VxD identifier
SeeAlso: INT 2F/AX=1684h"DEVICE API",INT 30"Windows",#01265,#01340

(Table 01278)
Values for BlockDev/IOS (VxD ID 0010h) service number:
 0000h	get version
 0001h	register device
 0002h	find INT 13 drive
 0003h	get device list
 0004h	send command
 0005h	command complete
 0006h	synchronous command
 0007h	"IOS_Register"
 0008h	"IOS_Requestor_Service"
 0009h	"IOS_Exclusive_Access"
 000Ah	"IOS_Send_Next_Command"
 000Bh	"IOS_Set_Async_Time_Out"
 000Ch	"IOS_Signal_Semaphore_No_Switch"
 000Dh	"IOSIdleStatus"
 000Eh	"IOSMapIORSToI24"
 000Fh	"IOSMapIORSToI21"
 0010h	"PrintLog"
SeeAlso: #01277,#01279

INT 20 P - Microsoft Windows - VMCPD - VxD SERVICES
	VxD = 0011h
Note:	the desired VxD and service number are identified by the data
	  immediately following the INT 20 instruction, as in:
		INT	20h
		DW	service number
		DW	VxD identifier
SeeAlso: INT 2F/AX=1684h"DEVICE API",INT 30"Windows",#01265,#01340

(Table 01279)
Values for VMCPD (VxD ID 0011h) service number:
 0000h	"VMCPD_Get_Version"
 0001h	"VMCPD_Get_Virt_State"
 0002h	"VMCPD_Set_Virt_State"
 0003h	"VMCPD_Get_CR0_State"
 0004h	"VMCPD_Set_CR0_State"
 0005h	"VMCPD_Get_Thread_State"
 0006h	"VMCPD_Set_Thread_State"
 0007h	"_VMCPD_Get_FP_Instruction_Size"
 0008h	"VMCPD_Set_Thread_Precision"
SeeAlso: #01278,#01280,#02642

INT 20 P - Microsoft Windows - EBIOS - VxD SERVICES
	VxD = 0012h
Note:	the desired VxD and service number are identified by the data
	  immediately following the INT 20 instruction, as in:
		INT	20h
		DW	service number
		DW	VxD identifier
SeeAlso: INT 2F/AX=1684h"DEVICE API",INT 30"Windows",#01265,#01340

(Table 01280)
Values for EBIOS (VxD ID 0012h) service number:
 00h	get EBIOS version
 01h	get unused memory
SeeAlso: #01279,#01281

INT 20 P - Microsoft Windows - VNETBIOS - VxD SERVICES
	VxD = 0014h
Note:	the desired VxD and service number are identified by the data
	  immediately following the INT 20 instruction, as in:
		INT	20h
		DW	service number
		DW	VxD identifier
SeeAlso: INT 2F/AX=1684h"DEVICE API",INT 30"Windows",#01265,#01340

(Table 01281)
Values for VNETBIOS (VxD ID 0014h) service number:
 00h	get version
 01h	register
 02h	submit
 03h	enum
 04h	deregister
 05h	register2
 06h	map
 07h	enum2
SeeAlso: #01280,#01282

INT 20 P - Microsoft Windows - DOSMGR - VxD SERVICES
	VxD = 0015h
Note:	the desired VxD and service number are identified by the data
	  immediately following the INT 20 instruction, as in:
		INT	20h
		DW	service number
		DW	VxD identifier
SeeAlso: INT 2F/AX=1684h"DEVICE API",INT 30"Windows",#01265,#01340

(Table 01282)
Values for DOSMGR (VxD ID 0015h) service number:
 0000h	get version
 0001h	set exec VM data
 0002h	coyp VM drive state
 0003h	execute VM
 0004h	get InDOS pointer
 0005h	add device
 0006h	remove device
 0007h	instance device
 0008h	get DOS critical status
 0009h	enable InDOS polling
 000Ah	backfill allowed
 000Bh	"LocalGlobalReg"
 000Ch	"Init_UMB_Area"
 000Dh	"Begin_V86_App"
 000Eh	"End_V86_App"
 000Fh	"Alloc_Local_Sys_VM_Mem"
	EAX = number of paragraphs??? to allocate
 0010h	"DOSMGR_Grow_CDSs"
 0011h	"DOSMGR_Translate_Server_DOS_Call"
 0012h	"DOSMGR_MMGR_PSP_Change_Notifier"
SeeAlso: #01281,#02656 at INT 2F/AX=1684h/BX=0015h

INT 20 P - Microsoft Windows - SHELL - VxD SERVICES
	VxD = 0017h
Note:	the desired VxD and service number are identified by the data
	  immediately following the INT 20 instruction, as in:
		INT	20h
		DW	service number
		DW	VxD identifier
SeeAlso: INT 2F/AX=1684h"DEVICE API",INT 30"Windows",#01265,#01340

(Table 01283)
Values for SHELL (VxD ID 0017h) service number:
 0000h	get version
 0001h	resolve contention
 0002h	event
 0003h	SYSMODAL message
 0004h	message
 0005h	get VM information
 0006h	"_SHELL_PostMessage"
 0007h	"_SHELL_WinExec"
 0008h	"_SHELL_CallDll"
 0009h	"SHELL_OpenClipboard"
 000Ah	"SHELL_SetClipboardData"
 000Bh	"SHELL_GetClipboardData"
 000Ch	"SHELL_CloseClipboard"
 000Dh	"_SHELL_Install_Taskman_Hooks"
 000Eh	"SHELL_Hook_Properties"
 000Fh	"SHELL_Unhook_Properties"
 0010h	"SHELL_OEMKeyScan"
 0011h	"SHELL_Update_User_Activity"
 0012h	"_SHELL_UnhookSystemBroadcast"
 0013h	"_SHELL_LocalAllocEx"
 0014h	"_SHELL_LocalFree"
 0015h	"_SHELL_LoadLibrary"
 0016h	"_SHELL_FreeLibrary"
 0017h	"_SHELL_GetProcAddress"
 0018h	"_SHELL_CallDll"
 0019h	"_SHELL_SuggestSingleMSDOSMode"
 001Ah	"SHELL_CheckHotkeyAllowed"
 001Bh	"_SHELL_GetDOSAppInfo"
SeeAlso: #01282,#01284,#02657 at INT 2F/AX=1684h/BX=0017h

INT 20 P - Microsoft Windows - VMPoll - VxD SERVICES
	VxD = 0018h
Note:	the desired VxD and service number are identified by the data
	  immediately following the INT 20 instruction, as in:
		INT	20h
		DW	service number
		DW	VxD identifier
SeeAlso: INT 2F/AX=1684h"DEVICE API",INT 30"Windows",#01265,#01340

(Table 01284)
Values for VMPoll (VxD ID 0018h) service number:
 00h	get version
 01h	enable/disable
 02h	reset detection
 03h	check idle
SeeAlso: #01269,#02657 at INT 2F/AX=1684h/BX=0017h

INT 20 P - Microsoft Windows - DOSNET - VxD SERVICES
	VxD = 001Ah
Note:	the desired VxD and service number are identified by the data
	  immediately following the INT 20 instruction, as in:
		INT	20h
		DW	service number
		DW	VxD identifier
SeeAlso: INT 2F/AX=1684h"DEVICE API",INT 30"Windows",#01265,#01340

(Table 01285)
Values for DOSNET (VxD ID 001Ah) service number:
 00h	get version
 01h	send FILESYSCHANGE
 02h	do PSP adjust
SeeAlso: #01284,#01286

INT 20 P - Microsoft Windows - VFD - VxD SERVICES
	VxD = 001Bh
Note:	the desired VxD and service number are identified by the data
	  immediately following the INT 20 instruction, as in:
		INT	20h
		DW	service number
		DW	VxD identifier
SeeAlso: INT 2F/AX=1684h"DEVICE API",INT 30"Windows",#01286,#01340

(Table 01286)
Values for VFD (VxD ID 001Bh) service number:
 0000h	get version
SeeAlso: #01285,#01287

INT 20 P - Microsoft Windows - LoadHi - VxD SERVICES
	VxD = 001Ch
Note:	the desired VxD and service number are identified by the data
	  immediately following the INT 20 instruction, as in:
		INT	20h
		DW	service number
		DW	VxD identifier
SeeAlso: INT 2F/AX=1684h"DEVICE API",INT 30"Windows",#01265,#01340

(Table 01287)
Values for LoadHi (VxD ID 001Ch) service number:
 00h	get version
	Return:	CF clear
		EAX = version (AH = major, AL = minor)
		ESI -> ASCIZ signature "LoadHi"
SeeAlso: #01286,#01288

INT 20 P - Microsoft Windows - Int13 - VxD SERVICES
	VxD = 0020h
Note:	the desired VxD and service number are identified by the data
	  immediately following the INT 20 instruction, as in:
		INT	20h
		DW	service number
		DW	VxD identifier
SeeAlso: INT 2F/AX=1684h"DEVICE API",INT 30"Windows",#01265,#01340

(Table 01288)
Values for Int13 (VxD ID 0020h) service number:
 00h	get version
 01h	device registered
 02h	translate VM interrupt
 03h	hooking BIOS interrupt
 04h	unhooking BIOS interrupt
SeeAlso: #01287,#01289

INT 20 P - Microsoft Windows - PAGEFILE - VxD SERVICES
	VxD = 0021h
Note:	the desired VxD and service number are identified by the data
	  immediately following the INT 20 instruction, as in:
		INT	20h
		DW	service number
		DW	VxD identifier
SeeAlso: INT 2F/AX=1684h"DEVICE API",INT 30"Windows",#01265,#01340

(Table 01289)
Values for PAGEFILE (VxD ID 0021h) service number:
 00h	get version
 01h	init file
 02h	clean up
 03h	grow file
 04h	read or write
 05h	cancel
 06h	test I/O valid
 07h	"Get_Size_Info"
 08h	"Set_Async_Manager"
 09h	"Call_Async_Manager"
SeeAlso: #01288,#02661 at INT 2F/AX=1684h/BX=0021h

INT 20 P - Microsoft Windows - VPOWERD - VxD SERVICES
	VxD = 0026h
Note:	the desired VxD and service number are identified by the data
	  immediately following the INT 20 instruction, as in:
		INT	20h
		DW	service number
		DW	VxD identifier
SeeAlso: INT 2F/AX=1684h"DEVICE API",INT 30"Windows",#01265,#01340

(Table 01290)
Values for VPOWERD (VxD ID 0026h) service number:
 00h	get version
	Return:	CF clear
		EAX = version (AH = major, AL = minor)
 01h	get APM BIOS version
	Return: CF clear
		EAX = APM BIOS version
 02h	get current power management level
	Return: CF clear
		EAX = power management level
 03h	enable/disable power management (see INT 15/AX=5308h)
	Return: EAX = error code (see #02665) or 00000000h if successful
 04h	set power state (see INT 15/AX=5307h)
	???
	Return: EAX = error code (see #02665) or 00000000h if successful
 05h	set system power status
	Return: EAX = error code (see #02665) or 00000000h if successful
 06h	restore APM power-on defaults (see INT 15/AX=5309h)
	Return: EAX = error code (see #02665) or 00000000h if successful
 07h	get power status (see INT 15/AX=530Ah)
	Return: ???
 08h	get APM 1.1 power state (see INT 15/AX=530Ch)
	Return: ???
 09h	invoke OEM APM function
	??? -> bufer containing parameters for INT 15/AX=5380h
	Return: EAX = error code (see #02665) or 00000000h if successful
		buffer updated if successful
 0Ah	register power handler
	???
	Return: EAX = error code (see #02665) or 00000000h if successful
 0Bh	deregister power handler
	???
	Return: EAX = error code (see #02665) or 00000000h if successful
 0Ch	Win32 get system power status
 0Dh	Win32 set system power status
SeeAlso: #01289,#01291,INT 2F/AX=1684h/BX=0026h

INT 20 P - Microsoft Windows - VXDLDR - VxD SERVICES
	VxD = 0027h
Note:	the desired VxD and service number are identified by the data
	  immediately following the INT 20 instruction, as in:
		INT	20h
		DW	service number
		DW	VxD identifier
SeeAlso: INT 2F/AX=1684h"DEVICE API",INT 30"Windows",#01265,#01340

(Table 01291)
Values for VXDLDR (VxD ID 0027h) service number:
 0000h	"VXDLDR_Get_Version"
 0001h	"VXDLDR_LoadDevice"
 0002h	"VXDLDR_UnloadDevice"
 0003h	"VXDLDR_DevInitSucceeded"
 0004h	"VXDLDR_DevInitFailed"
 0005h	"VXDLDR_GetDeviceList"
 0006h	"VXDLDR_UnloadMe"
 0007h	"PELDR_LoadModule"
 0008h	"PELDR_GetModuleHandle"
 0009h	"PELDR_GetModuleUsage"
 000Ah	"PELDR_GetEntryPoint"
 000Bh	"PELDR_GetProcAddress"
 000Ch	"PELDR_AddExportTable"
 000Dh	"PELDR_RemoveExportTable"
 000Eh	"PELDR_FreeModule"
 000Fh	"VXDLDR_Notify"
 0010h	"_PELDR_InitCompleted"
 0011h	"_PELDR_LoadModuleEx"
SeeAlso: #01289,#01292

INT 20 P - Microsoft Windows - NDIS - VxD SERVICES
	VxD = 0028h
Note:	the desired VxD and service number are identified by the data
	  immediately following the INT 20 instruction, as in:
		INT	20h
		DW	service number
		DW	VxD identifier
SeeAlso: INT 2F/AX=1684h"DEVICE API",INT 30"Windows",#01265,#01340

(Table 01292)
Values for NDIS (VxD ID 0028h) service number:
 00h	"NdisGetVersion"
 01h	"NdisAllocateSpinLock"
 02h	"NdisFreeSpinLock"
 03h	"NdisAcquireSpinLock"
 04h	"NdisReleaseSpinLock"
 05h	"NdisOpenConfiguration"
 06h	"NdisReadConfiguration"
 07h	"NdisCloseConfiguration"
 08h	"NdisReadEisaSlotInformation"
 09h	"NdisReadMcaPosInformation"
 0Ah	"NdisAllocateMemory"
 0Bh	"NdisFreeMemory"
 0Ch	"NdisSetTimer"
 0Dh	"NdisCancelTimer"
 0Eh	"NdisStallExecution"
 0Fh	"NdisInitializeInterrupt"
 10h	"NdisRemoveInterrupt"
 11h	"NdisSynchronizeWithInterrupt"
 12h	"NdisOpenFile"
 13h	"NdisMapFile"
 14h	"NdisUnmapFile"
 15h	"NdisCloseFile"
 16h	"NdisAllocatePacketPool"
 17h	"NdisFreePacketPool"
 18h	"NdisAllocatePacket"
 19h	"NdisReinitializePacket"
 1Ah	"NdisFreePacket"
 1Bh	"NdisQueryPacket"
 1Ch	"NdisAllocateBufferPool"
 1Dh	"NdisFreeBufferPool"
 1Eh	"NdisAllocateBuffer"
 1Fh	"NdisCopyBuffer"
 20h	"NdisFreeBuffer"
 21h	"NdisQueryBuffer"
 22h	"NdisGetBufferPhysicalAddress"
 23h	"NdisChainBufferAtFront"
 24h	"NdisChainBufferAtBack"
 25h	"NdisUnchainBufferAtFront"
 26h	"NdisUnchainBufferAtBack"
 27h	"NdisGetNextBuffer"
 28h	"NdisCopyFromPacketToPacket"
 29h	"NdisRegisterProtocol"
 2Ah	"NdisDeregisterProtocol"
 2Bh	"NdisOpenAdapter"
 2Ch	"NdisCloseAdapter"
 2Dh	"NdisSend"
 2Eh	"NdisTransferData"
 2Fh	"NdisReset"
 30h	"NdisRequest"
 31h	"NdisInitializeWrapper"
 32h	"NdisTerminateWrapper"
 33h	"NdisRegisterMac"
 34h	"NdisDeregisterMac"
 35h	"NdisRegisterAdapter"
 36h	"NdisDeregisterAdapter"
 37h	"NdisCompleteOpenAdapter"
 38h	"NdisCompleteCloseAdapter"
 39h	"NdisCompleteSend"
 3Ah	"NdisCompleteTransferData"
 3Bh	"NdisCompleteReset"
 3Ch	"NdisCompleteRequest"
 3Dh	"NdisIndicateReceive"
 3Eh	"NdisIndicateReceiveComplete"
 3Fh	"NdisIndicateStatus"
 40h	"NdisIndicateStatusComplete"
 41h	"NdisCompleteQueryStatistics"
 42h	"NdisEqualString"
 43h	"NdisNetAddressStringToBinary"
 44h	"NdisReadNetworkAddress"
 45h	"NdisWriteErrorLogEntry"
 46h	"C_MapPhysToLinear"
 47h	"C_HeapFree"
 48h	"NdisAllocateSharedMemory"
 49h	"NdisFreeSharedMemory"
 ...
 5Fh	...last service for Windows95 SP1
SeeAlso: #01291,#01293

INT 20 P - Microsoft Windows - VWIN32 - VxD SERVICES
	VxD = 002Ah
Note:	the desired VxD and service number are identified by the data
	  immediately following the INT 20 instruction, as in:
		INT	20h
		DW	service number
		DW	VxD identifier
SeeAlso: INT 2F/AX=1684h"DEVICE API",INT 30"Windows",#01265,#01340

(Table 01293)
Values for VWIN32 (VxD ID 002Ah) service number:
 0000h	"VWin32_Get_Version"
 0001h	"VWin32_Wake_For_Event"
 0002h	"_VWIN32_QueueUserApc"
 0003h	"_VWIN32_Get_Thread_Context"
 0004h	"_VWIN32_Set_Thread_Context"
 0005h	"_VWIN32_CopyMem"
 0006h	"_VWIN32_BlockForTermination"
 0007h	"_VWIN32_Emulate_Npx"
 0008h	"_VWIN32_CheckDelayedNpxTrap"
 0009h	"VWIN32_EnterCrstR0"
 000Ah	"VWIN32_LeaveCrstR0"
 000Bh	"_VWIN32_FaultPopup"
 000Ch	"VWIN32_GetContextHandle"
 000Dh	"VWIN32_GetCurrentProcessHandle"
 000Eh	"_VWIN32_SetWin32Event"
 000Fh	"_VWIN32_PulseWin32Event"
 0010h	"_VWIN32_ResetWin32Event"
 0011h	"_VWIN32_WaitSingleObject"
 0012h	"_VWIN32_WaitMultipleObjects"
 0013h	"_VWIN32_CreateRing0Thread"
 0014h	"_VWIN32_CloseVxDHandle"
 0015h	"VWIN32_ActiveTimeBiasSet"
 0016h	"VWIN32_GetCurrentDirectory"
 0017h	"VWIN32_BlueScreenPopup"
 0018h	"VWIN32_TerminateApp"
 0019h	"_VWIN32_QueueKernelAPC"
 001Ah	"VWIN32_SysErrorBox"
 001Bh	"_VWIN32_IsClientWin32"
 001Ch	"VWIN32_IFSRIPWhenLev2Taken"
SeeAlso: #01292,#01294

INT 20 P - Microsoft Windows - VCOMM - VxD SERVICES
	VxD = 002Bh
Note:	the desired VxD and service number are identified by the data
	  immediately following the INT 20 instruction, as in:
		INT	20h
		DW	service number
		DW	VxD identifier
SeeAlso: INT 2F/AX=1684h"DEVICE API",INT 30"Windows",#01265,#01340

(Table 01294)
Values for VCOMM (VxD ID 002Bh) service number:
 0000h	"VCOMM_Get_Version"
 0001h	"_VCOMM_Register_Port_Driver"
 0002h	"_VCOMM_Acquire_Port"
 0003h	"_VCOMM_Release_Port"
 0004h	"_VCOMM_OpenComm"
 0005h	"_VCOMM_SetCommState"
 0006h	"_VCOMM_GetCommState"
 0007h	"_VCOMM_SetupComm"
 0008h	"_VCOMM_TransmitCommChar"
 0009h	"_VCOMM_CloseComm"
 000Ah	"_VCOMM_GetCommQueueStatus"
 000Bh	"_VCOMM_ClearCommError"
 000Ch	"_VCOMM_GetModemStatus"
 000Dh	"_VCOMM_GetCommProperties"
 000Eh	"_VCOMM_EscapeCommFunction"
 000Fh	"_VCOMM_PurgeComm"
 0010h	"_VCOMM_SetCommEventMask"
 0011h	"_VCOMM_GetCommEventMask"
 0012h	"_VCOMM_WriteComm"
 0013h	"_VCOMM_ReadComm"
 0014h	"_VCOMM_EnableCommNotification"
 0015h	"_VCOMM_GetLastError"
 0016h	"_VCOMM_Steal_Port"
 0017h	"_VCOMM_SetReadCallBack"
 0018h	"_VCOMM_SetWriteCallBack"
 0019h	"_VCOMM_GetSetCommTimeouts"
 001Ah	"_VCOMM_SetWriteRequest"
 001Bh	"_VCOMM_SetReadRequest"
 001Ch	"_VCOMM_Dequeue_Request"
 001Dh	"_VCOMM_Dequeue_Request"
 001Eh	"_VCOMM_Enumerate_DevNodes"
 001Fh	"VCOMM_Map_Win32DCB_To_Ring0"
 0020h	"VCOMM_Map_Ring0DCB_To_Win32"
 0021h	"_VCOMM_Get_Contention_Handler"
 0022h	"_VCOMM_Map_Name_To_Resource"
SeeAlso: #01293,#01295

INT 20 P - Microsoft Windows - SPOOLER - VxD SERVICES
	VxD = 002Ch
Note:	the desired VxD and service number are identified by the data
	  immediately following the INT 20 instruction, as in:
		INT	20h
		DW	service number
		DW	VxD identifier
SeeAlso: INT 2F/AX=1684h"DEVICE API",INT 30"Windows",#01265,#01340

(Table 01295)
Values for SPOOLER (VxD ID 002Ch) service number:
 0000h	get version???
 0001h	???
 0010h	...last service for Windows95 SP1
SeeAlso: #01294,#01296

INT 20 P - Microsoft Windows - VSERVER - VxD SERVICES
	VxD = 0032h
Note:	the desired VxD and service number are identified by the data
	  immediately following the INT 20 instruction, as in:
		INT	20h
		DW	service number
		DW	VxD identifier
SeeAlso: INT 2F/AX=1684h"DEVICE API",INT 30"Windows",#01265,#01340

(Table 01296)
Values for VSERVER (VxD ID 0032h) service number:
 00h	get VSERVER version
	Return: CF clear
		EAX = version (AH = major, AL = minor)
		EBX = ??? (00000000h)
 01h	allocate ???
	AX = ???
	ESI = ???
	Return: CF clear if successful
		CF set on error (table full)
 02h	NOP???
	Return: EBX = 00000000h
 03h	???
	Return: ZF clear
SeeAlso: #01295,#01297,INT 2F/AX=1684h/BX=0032h

INT 20 P - Microsoft Windows - CONFIGMG - VxD SERVICES
	VxD = 0033h
Note:	the desired VxD and service number are identified by the data
	  immediately following the INT 20 instruction, as in:
		INT	20h
		DW	service number
		DW	VxD identifier
SeeAlso: INT 2F/AX=1684h"DEVICE API",INT 30"Windows",#01265,#01340

(Table 01297)
Values for CONFIGMG (VxD ID 0033h) service number:
 0000h	"_CONFIGMG_Get_Version"
 0001h	"_CONFIGMG_Initialize"
 0002h	"_CONFIGMG_Locate_DevNode"
 0003h	"_CONFIGMG_Get_Parent"
 0004h	"_CONFIGMG_Get_Child"
 0005h	"_CONFIGMG_Get_Sibling"
 0006h	"_CONFIGMG_Get_Device_ID_Size"
 0007h	"_CONFIGMG_Get_Device_ID"
 0008h	"_CONFIGMG_Get_Depth"
 0009h	"_CONFIGMG_Get_Private_DWord"
 000Ah	"_CONFIGMG_Set_Private_DWord"
 000Bh	"_CONFIGMG_Create_DevNode"
 000Ch	"_CONFIGMG_Query_Remove_SubTree"
 000Dh	"_CONFIGMG_Remove_SubTree"
 000Eh	"_CONFIGMG_Register_Device_Driver"
 000Fh	"_CONFIGMG_Register_Enumerator"
 0010h	"_CONFIGMG_Register_Arbitrator"
 0011h	"_CONFIGMG_Deregister_Arbitrator"
 0012h	"_CONFIGMG_Query_Arbitrator_Free_Size"
 0013h	"_CONFIGMG_Query_Arbitrator_Free_Data"
 0014h	"_CONFIGMG_Sort_NodeList"
 0015h	"_CONFIGMG_Yield"
 0016h	"_CONFIGMG_Lock"
 0017h	"_CONFIGMG_Unlock"
 0018h	"_CONFIGMG_Add_Empty_Log_Conf"
 0019h	"_CONFIGMG_Free_Log_Conf"
 001Ah	"_CONFIGMG_Get_First_Log_Conf"
 001Bh	"_CONFIGMG_Get_Next_Log_Conf"
 001Ch	"_CONFIGMG_Add_Res_Des"
 001Dh	"_CONFIGMG_Modify_Res_Des"
 001Eh	"_CONFIGMG_Free_Res_Des"
 001Fh	"_CONFIGMG_Get_Next_Res_Des"
 0020h	"_CONFIGMG_Get_Performance_Info"
 0021h	"_CONFIGMG_Get_Res_Des_Data_Size"
 0022h	"_CONFIGMG_Get_Res_Des_Data"
 0023h	"_CONFIGMG_Process_Events_Now"
 0024h	"_CONFIGMG_Create_Range_List"
 0025h	"_CONFIGMG_Add_Range"
 0026h	"_CONFIGMG_Delete_Range"
 0027h	"_CONFIGMG_Test_Range_Available"
 0028h	"_CONFIGMG_Dup_Range_List"
 0029h	"_CONFIGMG_Free_Range_List"
 002Ah	"_CONFIGMG_Invert_Range_List"
 002Bh	"_CONFIGMG_Intersect_Range_List"
 002Ch	"_CONFIGMG_First_Range"
 002Dh	"_CONFIGMG_Next_Range"
 002Eh	"_CONFIGMG_Dump_Range_List"
 002Fh	"_CONFIGMG_Load_DLVxDs"
 0030h	"_CONFIGMG_Get_DDBs"
 0031h	"_CONFIGMG_Get_CRC_CheckSum"
 0032h	"_CONFIGMG_Register_DevLoader"
 0033h	"_CONFIGMG_Reenumerate_DevNode"
 0034h	"_CONFIGMG_Setup_DevNode"
 0035h	"_CONFIGMG_Reset_Children_Marks"
 0036h	"_CONFIGMG_Get_DevNode_Status"
 0037h	"_CONFIGMG_Remove_Unmarked_Children"
 0038h	"_CONFIGMG_ISAPNP_To_CM"
 0039h	"_CONFIGMG_CallBack_Device_Driver"
 003Ah	"_CONFIGMG_CallBack_Enumerator"
 003Bh	"_CONFIGMG_Get_Alloc_Log_Conf"
 003Ch	"_CONFIGMG_Get_DevNode_Key_Size"
 003Dh	"_CONFIGMG_Get_DevNode_Key"
 003Eh	"_CONFIGMG_Read_Registry_Value"
 003Fh	"_CONFIGMG_Write_Registry_Value"
 0040h	"_CONFIGMG_Disable_DevNode"
 0041h	"_CONFIGMG_Enable_DevNode"
 0042h	"_CONFIGMG_Move_DevNode"
 0043h	"_CONFIGMG_Set_Bus_Info"
 0044h	"_CONFIGMG_Get_Bus_Info"
 0045h	"_CONFIGMG_Set_HW_Prof"
 0046h	"_CONFIGMG_Recompute_HW_Prof"
 0047h	"_CONFIGMG_Query_Change_HW_Prof"
 0048h	"_CONFIGMG_Get_Device_Driver_Private_DWord"
 0049h	"_CONFIGMG_Set_Device_Driver_Private_DWord"
 004Ah	"_CONFIGMG_Get_HW_Prof_Flags"
 004Bh	"_CONFIGMG_Set_HW_Prof_Flags"
 004Ch	"_CONFIGMG_Read_Registry_Log_Confs"
 004Dh	"_CONFIGMG_Run_Detection"
 004Eh	"_CONFIGMG_Call_At_Appy_Time"
 004Fh	"_CONFIGMG_Fail_Change_HW_Prof"
 0050h	"_CONFIGMG_Set_Private_Problem"
 0051h	"_CONFIGMG_Debug_DevNode"
 0052h	"_CONFIGMG_Get_Hardware_Profile_Info"
 0053h	"_CONFIGMG_Register_Enumerator_Function"
 0054h	"_CONFIGMG_Call_Enumerator_Function"
 0055h	"_CONFIGMG_Add_ID"
 0056h	"_CONFIGMG_Find_Range"
 0057h	"_CONFIGMG_Get_Global_State"
 0058h	"_CONFIGMG_Broadcast_Device_Change_Message"
 0059h	"_CONFIGMG_Call_DevNode_Handler"
 005Ah	"_CONFIGMG_Remove_Reinsert_All"
Note:	the VxD services appear to be identical to the PM/V86 APIs on
	  INT 2F/AX=1684h
SeeAlso: #01296,#01299,INT 2F/AX=1684h/BX=0033h

INT 20 P - Microsoft Windows - DWCFGMG.SYS - VxD SERVICES
	VxD = 0034h
Note:	the desired VxD and service number are identified by the data
	  immediately following the INT 20 instruction, as in:
		INT	20h
		DW	service number
		DW	VxD identifier
SeeAlso: INT 2F/AX=1684h"DEVICE API",INT 30"Windows",#01265,#01340

(Table 01298)
Values for DWCFGMG.SYS (VxD ID 0034h) service number:
 00h	"CM_GetVersion" get supported DDI version
	Return: EAX = 00000000h if not installed
		else
		    AH = major version number
		    AL = minor version number
		    EBX = number of devices controlled by DWCFGMG.SYS
 01h	"CM_GetConfig" get device configuration
	EBX = device index
	EDI -> buffer for configuration information (see #02675)
	Return: EAX = status (0000h successful, 0001h index out of range)
 02h	"CM_LockConfig" lock device configuration
	EDI -> configuration information (see #02675)
	Return: EAX = status
		    0000h successful
		    0001h resource conflict
		    0002h invalid request
 03h	"CM_UnlockConfig" unlock device configuration
	EDI -> configuration information (see #02675)
	Return: EAX = status (0000h successful, 0001h invalid request)
 04h	"CME_QueryResources"
 05h	"CME_AllocResources"
 06h	"CME_DeallocResources"
SeeAlso: INT 2F/AX=1684h/BX=0034h

INT 20 P - Microsoft Windows - VFBACKUP - VxD SERVICES
	VxD = 0036h
Note:	the desired VxD and service number are identified by the data
	  immediately following the INT 20 instruction, as in:
		INT	20h
		DW	service number
		DW	VxD identifier
SeeAlso: INT 2F/AX=1684h"DEVICE API",INT 30"Windows",#01265,#01340

(Table 01299)
Values for VFBACKUP (VxD ID 0036h) service number:
 0000h	get version
	Return: CF clear
		EAX = version (AH = major, AL = minor)
 0001h	"VFBACKUP_Lock_NEC"
 0002h	"VFBACKUP_UnLock_NEC"
 0003h	"VFBACKUP_Register_NEC"
 0004h	"VFBACKUP_Register_VFD"
 0005h	"VFBACKUP_Lock_All_Ports"
SeeAlso: #01297,#01300

INT 20 P - Microsoft Windows - VMINI / ENABLE - VxD SERVICES
	VxD = 0037h
Note:	the desired VxD and service number are identified by the data
	  immediately following the INT 20 instruction, as in:
		INT	20h
		DW	service number
		DW	VxD identifier
SeeAlso: INT 2F/AX=1684h"DEVICE API",INT 30"Windows",#01265,#01340

(Table 01300)
Values for VMINI / ENABLE (VxD ID 0037h) service number:
 0000h	get version
	Return: CF clear
		EAX = version (AH = major, AL = minor)
 0001h	"VMINI_Update"
	??? (performs VMMCall 1800Eh, then falls through to service 04h)
	Return: EAX = system time???
 0002h	"VMINI_Status"
	get current ???
	Return: EAX = ???
 0003h	"VMINI_DisplayError" (schedules a global event via VMMCall 1800Eh)
	Return: ???
 0004h	"VMINI_SetTimeStamp" (performs VMMCall 100CFh)
	Return: EAX = system time
 0005h	"VMINI_Siren" (call ??? priority event)
	Return: nothing
 0006h	"VMINI_RegisterAccess" (set ??? / get ???)
	EDI -> buffer containing data to copy into VxD and space for results
	Return: EDI buffer updated
 0007h	"VMINI_GetData"
	EBX = ??? flags (bits 2,15,17,18 checked)
	EDI -> ???
	???
	Return: ???
 0008h	"VMINI_ShutDownItem" (schedules a global event via VMMCall 1800Eh)
	Return: ???
 0009h	"VMINI_RegisterSK" (get ??? data)
	EDI -> buffer for data (see #01301)
	Return:	EDI buffer updated if large enough
SeeAlso: #01299,#01302,#02677 at INT 2F/AX=1684h/BX=0037h

Format of ENABLE.VXD ??? data:
Offset	Size	Description	(Table 01301)
 00h	DWORD	(ret) length of data, including this word
		(call) length of buffer
 04h	DWORD	-> 24-byte (or larger) buffer
 08h	DWORD	-> 20-byte buffer
 0Ch	DWORD	-> 260-byte buffer
 10h	DWORD	-> 260-byte buffer
SeeAlso: #01300

INT 20 P - Microsoft Windows - VCOND - VxD SERVICES
	VxD = 0038h
Note:	the desired VxD and service number are identified by the data
	  immediately following the INT 20 instruction, as in:
		INT	20h
		DW	service number
		DW	VxD identifier
SeeAlso: INT 2F/AX=1684h"DEVICE API",INT 30"Windows",#01265,#01340

(Table 01302)
Values for VCOND (VxD ID 0038h) service number:
 0000h	get VCOND version
	Return: CF clear
		EAX = version (AH = major, AL = minor)
 0001h	"VCOND_Launch_ConApp_Inherited"
SeeAlso: #01303,#01300,#01304

(Table 01303)
Values for Windows95 VCOND (Vxd ID 0038h) Win32 service number:
 00h	get VCOND version
	Return: EAX = version (AH = major, AL = minor)
 ...
 34h	...last Win32 service for Windows95 SP1
SeeAlso: #01302

INT 20 P - Microsoft Windows - BIOS - VxD SERVICES
	VxD = 003Dh
Note:	the desired VxD and service number are identified by the data
	  immediately following the INT 20 instruction, as in:
		INT	20h
		DW	service number
		DW	VxD identifier
SeeAlso: INT 2F/AX=1684h"DEVICE API",INT 30"Windows",#01265,#01340

(Table 01304)
Values for BIOS (VxD ID 003Dh) service number:
 00h	get version???
 01h	???
 02h	???
 03h	???
SeeAlso: #01302,#01305

INT 20 P - Microsoft Windows - WSOCK - VxD SERVICES
	VxD = 003Eh
Note:	the desired VxD and service number are identified by the data
	  immediately following the INT 20 instruction, as in:
		INT	20h
		DW	service number
		DW	VxD identifier
SeeAlso: INT 2F/AX=1684h"DEVICE API",INT 30"Windows",#01265,#01340

(Table 01305)
Values for WSOCK (VxD ID 003Eh) service number:
 00h	get WSOCK version
	Return: CF clear
		AH = major version
		AL = minor version
		EAX high word = 0000h
 01h	???
	EAX = ??? or 00000000h
	Return: CF clear if successful
		    EAX = 00000000h
		CF set on error
		    EAX = ???
 02h	???
	EAX = ??? or 00000000h
	Return: ???
 03h	???
 04h	...last service for Windows95 SP1
SeeAlso: #01304,#01306

INT 20 P - Microsoft Windows - IFSMgr - VxD SERVICES
	VxD = 0040h
Note:	the desired VxD and service number are identified by the data
	  immediately following the INT 20 instruction, as in:
		INT	20h
		DW	service number
		DW	VxD identifier
SeeAlso: INT 2F/AX=1684h"DEVICE API",INT 30"Windows",#01265,#01340

(Table 01306)
Values for IFSMGR (VxD ID 0040h) service number:
 00h	get version
 01h	"RegisterMount"
 02h	"RegisterNet"
 03h	"RegisterMailSlot"
 04h	"Attach"
 05h	"Detach"
 06h	"Get_NetTime"
 07h	"Get_DOSTime"
 08h	"SetupConnection"
 09h	"DerefConnection"
 0Ah	"ServerDOSCall"
 0Bh	"CompleteAsync"
 0Ch	"RegisterHeap"
 0Dh	"GetHeap"
 0Eh	"RetHeap"
 0Fh	"CheckHeap"
 10h	"CheckHeapItem"
 11h	"FillHeapSpare"
 12h	"Block"
 13h	"Wakeup"
 14h	"Yield"
 15h	"SchedEvent"
 16h	"QueueEvent"
 17h	"KillEvent"
 18h	"FreeIOReg"
 19h	"MakeMailSlot"
 1Ah	"DeleteMailSlot"
 1Bh	"WriteMailSlot"
 1Ch	"PopUp"
 1Dh	"printf"
 1Eh	"AssertFailed"
 1Fh	"LogEntry"
 20h	"DebugMenu"
 21h	"DebugVars"
 22h	"GetDebugString"
 23h	"GetDebugHexNum"
 24h	"NetFunction"
 25h	"DoDelAllUses"
 26h	"SetErrString"
 27h	"GetErrString"
 28h	"SetReqHook"
 29h	"SetPathHook"
 2Ah	"UseAdd"
 2Bh	"UseDel"
 2Ch	"InitUseAdd"
 2Dh	"ChangeDir"
 2Eh	"DelAllUses"
 2Fh	"CDROM_Attach"
 30h	"CDROM_Detach"
 31h	"Win32DupHandle"
 32h	"Ring0_FileIO"
 33h	"Toggle_Extended_File_Handle"
 34h	"IFSMgr_GetDrive_Info"
 35h	"IFSMgr_Ring0GetDriveInfo"
 36h	"IFSMgr_BlockNoEvents"
 37h	"IFSMgr_NetToDosTime"
 38h	"IFSMgr_DosToNetTime"
 39h	"IFSMgr_DosToWin32Time"
 3Ah	"IFSMgr_Win32ToDosTime"
 3Bh	"IFSMgr_NetToWin32Time"
 3Ch	"IFSMgr_Win32ToNetTime"
 3Dh	"IFSMgr_MetaMatch"
 3Eh	"IFSMgr_TransMatch"
 3Fh	"IFSMgr_CallProvider"
 40h	"UniToBCS"
 41h	"UniToBCSPath"
 42h	"BCSToUni"
 43h	"UniToUpper"
 44h	"UniCharToOEM"
 45h	"CreateBasis"
 46h	"MatchBasisName"
 47h	"AppendBasisTail"
 48h	"FcbToShort"
 49h	"ShortToFcb"
 4Ah	"IFSMgr_ParsePath"
 4Bh	"Query_PhysLock"
 4Ch	"_VolFlush"
 4Dh	"NotifyVolumeArrival"
 4Eh	"NotifyVolumeRemoval"
 4Fh	"QueryVolumeRemoval"
 50h	"IFSMgr_FSDUnmountCFSD"
 51h	"IFSMgr_GetConversionTablePtrs"
 52h	"IFSMgr_CheckAccessConflict"
 53h	"IFSMgr_LockFile"
 54h	"IFSMgr_UnlockFile"
 55h	"IFSMgr_RemoveLocks"
 56h	"IFSMgr_CheckLocks"
 57h	"IFSMgr_CountLocks"
 58h	"IFSMgr_ReassignLockFileInst"
 59h	"IFSMgr_UnassignLockList"
 5Ah	"IFSMgr_MountChildVolume"
 5Bh	"IFSMgr_UnmountChildVolume"
 5Ch	"IFSMgr_SwapDrives"
 5Dh	"IFSMgr_FSDMapFHtoIOREQ"
 5Eh	"IFSMgr_FSDParsePath"
 5Fh	"IFSMgr_FSDAttachSFT"
 60h	"IFSMgr_GetTimeZoneBias"
 61h	"IFSMgr_PNPEvent"
 62h	"IFSMgr_RegisterCFSD"
 63h	"IFSMgr_Win32MapExtendedHandleToSFT"
 64h	"IFSMgr_DbgSetFileHandleLimit"
 65h	"IFSMgr_Win32MapSFTToExtendedHandle"
 66h	"IFSMgr_FSDGetCurrentDrive"
 67h	"IFSMgr_InstallFileSystemApiHook"
 68h	"IFSMgr_RemoveFileSystemApiHook"
 69h	"IFSMgr_RunScheduledEvents"
 6Ah	"IFSMgr_CheckDelResource"
 6Bh	"IFSMgr_Win32GetVMCurdir"
 6Ch	"IFSMgr_SetupFailedConnection"
 6Dh	"_GetMappedErr"
 6Eh	"ShortToLossyFcb"
 6Fh	"IFSMgr_GetLockState"
 70h	"BcsToBcs"
 71h	"IFSMgr_SetLoopback"
 72h	"IFSMgr_ClearLoopback"
 73h	"IFSMgr_ParseOneElement"
 74h	"BcsToBcsUpper"
SeeAlso: #01305,#01307

INT 20 P - Microsoft Windows - VCDFSD - VxD SERVICES
	VxD = 0041h
Note:	the desired VxD and service number are identified by the data
	  immediately following the INT 20 instruction, as in:
		INT	20h
		DW	service number
		DW	VxD identifier
SeeAlso: INT 2F/AX=1684h"DEVICE API",INT 30"Windows",#01265,#01340

(Table 01307)
Values for VCDFSD (VxD ID 0041h) service number:
 00h	get VCDFSD version???
 01h	???
 02h	???
 03h	???
SeeAlso: #01306,#01308

INT 20 P - Microsoft Windows - PERF - VxD SERVICES
	VxD = 0048h
Note:	the desired VxD and service number are identified by the data
	  immediately following the INT 20 instruction, as in:
		INT	20h
		DW	service number
		DW	VxD identifier
SeeAlso: INT 2F/AX=1684h"DEVICE API",INT 30"Windows",#01265,#01340

(Table 01308)
Values for PERF (VxD ID 0048h) service number:
 00h	get version
	Return: CF clear
		EAX = version (AH = major, AL = minor)
 01h	"PERF_Server_Register"
	(creates/sets a registry key for the server)
 02h	"PERF_Server_Deregister"
	end performance monitoring (deletes registry key for server)
 03h	"PERF_Server_Add_Stat"
	start performance monitoring (creates/sets a registry key)
 04h	"PERF_Server_Remove_Stat"
	end performance monitoring (deletes registry key)
SeeAlso: #01307,#01311,#01309

INT 20 P - Microsoft Windows - MTRR - VxD SERVICES
	VxD = 004Ah
Note:	the desired VxD and service number are identified by the data
	  immediately following the INT 20 instruction, as in:
		INT	20h
		DW	service number
		DW	VxD identifier
SeeAlso: INT 2F/AX=1684h"DEVICE API",INT 30"Windows",#01265,#01340

(Table 01309)
Values for MTRR (VxD ID 004Ah) service number:
 00h	get version
 01h	??? (highest service defined for Win95B)
SeeAlso: #01308,#01310

INT 20 P - Microsoft Windows - NTKERN - VxD SERVICES
	VxD = 004Bh
Note:	the desired VxD and service number are identified by the data
	  immediately following the INT 20 instruction, as in:
		INT	20h
		DW	service number
		DW	VxD identifier
SeeAlso: INT 2F/AX=1684h"DEVICE API",INT 30"Windows",#01265,#01340

(Table 01310)
Values for NTKERN (VxD ID 004Bh) service number:
 00h	get version???
 ...
 08h	??? (highest service defined for Win95B)
SeeAlso: #01309,#01311

INT 20 P - Microsoft Windows - VFLATD - VxD SERVICES
	VxD = 011Fh
Note:	the desired VxD and service number are identified by the data
	  immediately following the INT 20 instruction, as in:
		INT	20h
		DW	service number
		DW	VxD identifier
SeeAlso: INT 2F/AX=1684h"DEVICE API",INT 30"Windows",#01265,#01340

(Table 01311)
Values for VFLATD (VxD ID 011Fh) service number:
 00h	get VFLATD version???
 01h	???
SeeAlso: #01308,#01312

INT 20 P - Microsoft Windows - vjoyd - VxD SERVICES
	VxD = 0449h
Note:	the desired VxD and service number are identified by the data
	  immediately following the INT 20 instruction, as in:
		INT	20h
		DW	service number
		DW	VxD identifier
SeeAlso: INT 2F/AX=1684h"DEVICE API",INT 30"Windows",#01265,#01340

(Table 01312)
Values for vjoyd (VxD ID 0449h) service number:
 00h	get vjoyd version???
 01h	???
SeeAlso: #01311,#01313

INT 20 P - Microsoft Windows - mmdevldr - VxD SERVICES
	VxD = 044Ah
Note:	the desired VxD and service number are identified by the data
	  immediately following the INT 20 instruction, as in:
		INT	20h
		DW	service number
		DW	VxD identifier
SeeAlso: INT 2F/AX=1684h"DEVICE API",INT 30"Windows",#01265,#01340

(Table 01313)
Values for mmdevldr (VxD ID 044Ah) service number:
 00h	get mmdevldr version???
 01h	???
 02h	???
 03h	???
 04h	???
 05h	???
SeeAlso: #01312,#01314

INT 20 P - Microsoft Windows - VNetSup - VxD SERVICES
	VxD = 0480h
Note:	the desired VxD and service number are identified by the data
	  immediately following the INT 20 instruction, as in:
		INT	20h
		DW	service number
		DW	VxD identifier
SeeAlso: INT 2F/AX=1684h"DEVICE API",INT 30"Windows",#01265,#01340

(Table 01314)
Values for VNetSup (VxD ID 0480h) service number:
 00h	get VNetSup version???
 01h	???
 02h	???
 03h	???
 04h	???
 05h	???
 06h	???
SeeAlso: #01313,#01315

INT 20 P - Microsoft Windows - VREDIR - VxD SERVICES
	VxD = 0481h
Note:	the desired VxD and service number are identified by the data
	  immediately following the INT 20 instruction, as in:
		INT	20h
		DW	service number
		DW	VxD identifier
SeeAlso: INT 2F/AX=1684h"DEVICE API",INT 30"Windows",#01265,#01340

(Table 01315)
Values for VREDIR (VxD ID 0481h) service number:
 0000h	"VRedir_Get_Version"
 0001h	"VRedir_Register"
 0002h	"VRedir_MakeMailSlot"
 0003h	"VRedir_DeleteMailSlot"
 0004h	"VRedir_ServerEnum"
 0010h	...last service for Windows95 SP1
SeeAlso: #01314,#01316

INT 20 P - Microsoft Windows - VSHARE - VxD SERVICES
	VxD = 0483h
Note:	the desired VxD and service number are identified by the data
	  immediately following the INT 20 instruction, as in:
		INT	20h
		DW	service number
		DW	VxD identifier
SeeAlso: INT 2F/AX=1684h"DEVICE API",INT 30"Windows",#01265,#01340

(Table 01316)
Values for VSHARE (VxD ID 0483h) service number:
 00h	get VSHARE version???
SeeAlso: #01315,#01317

INT 20 P - Microsoft Windows - NWLINK - VxD SERVICES
	VxD = 0487h
Note:	the desired VxD and service number are identified by the data
	  immediately following the INT 20 instruction, as in:
		INT	20h
		DW	service number
		DW	VxD identifier
SeeAlso: INT 2F/AX=1684h"DEVICE API",INT 30"Windows",#01265,#01340

(Table 01317)
Values for NWLINK (VxD ID 0487h) service number:
 00h	get NWLINK version???
 01h	???
 06h	...last service for Windows95 SP1
SeeAlso: #01316,#01318,#02642

INT 20 P - Microsoft Windows - VTDI - VxD SERVICES
	VxD = 0488h
Note:	the desired VxD and service number are identified by the data
	  immediately following the INT 20 instruction, as in:
		INT	20h
		DW	service number
		DW	VxD identifier
SeeAlso: INT 2F/AX=1684h"DEVICE API",INT 30"Windows",#01265,#01340

(Table 01318)
Values for VTDI (VxD ID 0488h) service number:
 00h	get VTDI version???
 01h	???
 08h	get ???
	seen called with DWORD -> ASCIZ "MSTCP" on stack, returning EAX=???
 0Dh	...last service for Windows95 SP1
SeeAlso: #01317,#01319

INT 20 P - Microsoft Windows - VIP - VxD SERVICES
	VxD = 0489h
Note:	the desired VxD and service number are identified by the data
	  immediately following the INT 20 instruction, as in:
		INT	20h
		DW	service number
		DW	VxD identifier
SeeAlso: INT 2F/AX=1684h"DEVICE API",INT 30"Windows",#01265,#01340

(Table 01319)
Values for VIP (VxD ID 0489h) service number:
 00h	get VIP version???
 01h	???
 05h	???
 06h	???
	returns EAX=0/1
 08h	...last service for Windows95 SP1
---Frontier Technologies' FTCVIP---
 09h	???
	returns EAX=1
SeeAlso: #01318,#01320

INT 20 P - Microsoft Windows - MSTCP - VxD SERVICES
	VxD = 048Ah
Note:	the desired VxD and service number are identified by the data
	  immediately following the INT 20 instruction, as in:
		INT	20h
		DW	service number
		DW	VxD identifier
SeeAlso: INT 2F/AX=1684h"DEVICE API",INT 30"Windows",#01265,#01340

(Table 01320)
Values for MSTCP (VxD ID 048Ah) service number:
 00h	get MSTCP version???
SeeAlso: #01319,#01321

INT 20 P - Microsoft Windows - VCACHE - VxD SERVICES
	VxD = 048Bh
Note:	the desired VxD and service number are identified by the data
	  immediately following the INT 20 instruction, as in:
		INT	20h
		DW	service number
		DW	VxD identifier
SeeAlso: INT 2F/AX=1684h"DEVICE API",INT 30"Windows",#01265,#01340

(Table 01321)
Values for VCACHE (VxD ID 048Bh) service number:
 0000h	"VCACHE_Get_Version"
 0001h	"VCACHE_Register"
 0002h	"VCACHE_GetSize"
 0003h	"VCACHE_CheckAvail"
 0004h	"VCACHE_FindBlock"
 0005h	"VCACHE_FreeBlock"
 0006h	"VCACHE_MakeMRU"
 0007h	"VCACHE_Hold"
 0008h	"VCACHE_Unhold"
 0009h	"VCACHE_Enum"
 000Ah	"VCACHE_TestHandle"
 000Bh	"VCACHE_VerifySums"
 000Ch	"VCACHE_RecalcSums"
 000Dh	"VCACHE_TestHold"
 000Eh	"VCACHE_GetStats"
 000Fh	"VCache_Deregister"
 0010h	"VCache_AdjustMinimum"
 0011h	"VCache_SwapBuffers"
 0012h	"VCache_RelinquishPage"
 0013h	"VCache_UseThisPage"
 0014h	"_VCache_CreateLookupCache"
 0015h	"_VCache_CloseLookupCache"
 0016h	"_VCache_DeleteLookupCache"
 0017h	"_VCache_Lookup"
 0018h	"_VCache_UpdateLookup"
SeeAlso: #01320,#01322

INT 20 P - Microsoft Windows - NWREDIR - VxD SERVICES
	VxD = 048Eh
Note:	the desired VxD and service number are identified by the data
	  immediately following the INT 20 instruction, as in:
		INT	20h
		DW	service number
		DW	VxD identifier
SeeAlso: INT 2F/AX=1684h"DEVICE API",INT 30"Windows",#01265,#01340

(Table 01322)
Values for NWREDIR (VxD ID 048Eh) service number:
 00h	get NWREDIR version???
 01h	???
SeeAlso: #01321,#01323

INT 20 P - Microsoft Windows - FILESEC - VxD SERVICES
	VxD = 0491h
Note:	the desired VxD and service number are identified by the data
	  immediately following the INT 20 instruction, as in:
		INT	20h
		DW	service number
		DW	VxD identifier
SeeAlso: INT 2F/AX=1684h"DEVICE API",INT 30"Windows",#01265,#01340

(Table 01323)
Values for FILESEC (VxD ID 0491h) service number:
 00h	get FILESEC version???
 01h	???
 10h	...last service for Windows95 SP1
SeeAlso: #01322,#01324

INT 20 P - Microsoft Windows - NWSERVER - VxD SERVICES
	VxD = 0492h
Note:	the desired VxD and service number are identified by the data
	  immediately following the INT 20 instruction, as in:
		INT	20h
		DW	service number
		DW	VxD identifier
SeeAlso: INT 2F/AX=1684h"DEVICE API",INT 30"Windows",#01265,#01340

(Table 01324)
Values for NWSERVER (VxD ID 0492h) service number:
 00h	get NWSERVER version???
 01h	???
 02h	???
 03h	???
SeeAlso: #01323,#01325

INT 20 P - Microsoft Windows - MSSP / NWSP - VxD SERVICES
	VxD = 0493h
Note:	the desired VxD and service number are identified by the data
	  immediately following the INT 20 instruction, as in:
		INT	20h
		DW	service number
		DW	VxD identifier
SeeAlso: INT 2F/AX=1684h"DEVICE API",INT 30"Windows",#01265,#01340

(Table 01325)
Values for MSSP/NWSP (VxD ID 0493h) service number:
 00h	get NSSP / NWSP version???
 01h	???
 06h	...last service for Windows95 SP1
SeeAlso: #01324,#01326

INT 20 P - Microsoft Windows - NSCL - VxD SERVICES
	VxD = 0494h
Note:	the desired VxD and service number are identified by the data
	  immediately following the INT 20 instruction, as in:
		INT	20h
		DW	service number
		DW	VxD identifier
SeeAlso: INT 2F/AX=1684h"DEVICE API",INT 30"Windows",#01265,#01340

(Table 01326)
Values for NSCL (VxD ID 0494h)	service number:
 00h	get NSCL version???
 01h	???
 02h	???
SeeAlso: #01325,#01327

INT 20 P - Microsoft Windows - AFVXD - VxD SERVICES
	VxD = 0495h
Note:	the desired VxD and service number are identified by the data
	  immediately following the INT 20 instruction, as in:
		INT	20h
		DW	service number
		DW	VxD identifier
SeeAlso: INT 2F/AX=1684h"DEVICE API",INT 30"Windows",#01265,#01340

(Table 01327)
Values for AFVXD (VxD ID 0495h) service number:
 00h	get version
	Return: CF clear
		AX = version (AH = high, AL = low)
 01h	???
	EAX -> ???
	EBX -> ???
	ECX = ???
	Return:	???
 02h	???
	EAX -> ???
	Return: ???
SeeAlso: #01326,#01328

INT 20 P - Microsoft Windows - NDIS2SUP - VxD SERVICES
	VxD = 0496h
Note:	the desired VxD and service number are identified by the data
	  immediately following the INT 20 instruction, as in:
		INT	20h
		DW	service number
		DW	VxD identifier (see #02642)
SeeAlso: INT 2F/AX=1684h"DEVICE API",INT 30"Windows",#01265,#01340

(Table 01328)
Values for NDIS2SUP (VxD ID 0496h) service number:
 00h	get NDIS2SUP version???
 01h	???
SeeAlso: #01327,#01329

INT 20 P - Microsoft Windows - Splitter - VxD SERVICES
	VxD = 0498h
Note:	the desired VxD and service number are identified by the data
	  immediately following the INT 20 instruction, as in:
		INT	20h
		DW	service number
		DW	VxD identifier (see #02642)
SeeAlso: INT 2F/AX=1684h"DEVICE API",INT 30"Windows",#01265,#01340

(Table 01329)
Values for Splitter (VxD ID 0498h) service number:
 00h	get Splitter version
	Return:	CF clear
		EAX = version (00000001h)
 01h	???
 02h	???
 03h	hook/unhook VMM "hook device service" service
	EAX = request (0 = unhook, nonzero = hook)
	Return: if EAX nonzero on entry, Splitter's service 04h replaces VMM
		  service 0090h; otherwise, default handler is restored
 04h	Splitter "hook device service" handler
SeeAlso: #01328,#01330

INT 20 P - Microsoft Windows - PPPMAC - VxD SERVICES
	VxD = 0499h
Note:	the desired VxD and service number are identified by the data
	  immediately following the INT 20 instruction, as in:
		INT	20h
		DW	service number
		DW	VxD identifier (see #02642)
SeeAlso: INT 2F/AX=1684h"DEVICE API",INT 30"Windows",#01265,#01340

(Table 01330)
Values for PPPMAC (VxD ID 0499h) service number:
 00h	???
 09h	...last service for Windows95 SP1
SeeAlso: #01329,#01331,#02642

INT 20 P - Microsoft Windows - VDHCP - VxD SERVICES
	VxD = 049Ah
Note:	the desired VxD and service number are identified by the data
	  immediately following the INT 20 instruction, as in:
		INT	20h
		DW	service number
		DW	VxD identifier (see #02642)
SeeAlso: INT 2F/AX=1684h"DEVICE API",INT 30"Windows",#01265,#01340

(Table 01331)
Values for VDHCP (VxD ID 049Ah) service number:
 00h	get VDHCP version???
 01h	???
 02h	???
 03h	???
SeeAlso: #01330,#01332

INT 20 P - Microsoft Windows - VNBT - VxD SERVICES
	VxD = 049Bh
Note:	the desired VxD and service number are identified by the data
	  immediately following the INT 20 instruction, as in:
		INT	20h
		DW	service number
		DW	VxD identifier (see #02642)
SeeAlso: INT 2F/AX=1684h"DEVICE API",INT 30"Windows",#01265,#01340

(Table 01332)
Values for VNBT (VxD ID 049Bh) service number:
 00h	get VNBT version???
SeeAlso: #01331,#01333

INT 20 P - Microsoft Windows - LOGGER - VxD SERVICES
	VxD = 049Dh
Note:	the desired VxD and service number are identified by the data
	  immediately following the INT 20 instruction, as in:
		INT	20h
		DW	service number
		DW	VxD identifier (see #02642)
SeeAlso: INT 2F/AX=1684h"DEVICE API",INT 30"Windows",#01265,#01340

(Table 01333)
Values for LOGGER (VxD ID 049Dh) service number:
 00h	get LOGGER version???
 01h	???
 02h	???
 03h	???
 04h	???
SeeAlso: #01332,#01334

INT 20 P - Microsoft Windows - PCCARD - VxD SERVICES
	VxD = 097Ch
Note:	the desired VxD and service number are identified by the data
	  immediately following the INT 20 instruction, as in:
		INT	20h
		DW	service number
		DW	VxD identifier (see #02642)
SeeAlso: INT 2F/AX=1684h"DEVICE API",INT 30"Windows",#01334,#01340

(Table 01334)
Values for PCCARD (VxD ID 097Ch) service number:
 0000h	"PCCARD_Get_Version"
 0001h	"PCCARD_Card_Services"
SeeAlso: #01333,#01337

INT 20 P - Frontier Technologies ??? - VxD SERVICES
	VxD = 3048h
Note:	the desired VxD and service number are identified by the data
	  immediately following the INT 20 instruction, as in:
		INT	20h
		DW	service number
		DW	VxD identifier
SeeAlso: INT 2F/AX=1684h"DEVICE API",INT 30"Windows",#01265,#01335

(Table 01335)
Values for ??? (VxD ID 3048h) service number:
 00h	get version???
 03h	???
	called with 5 DWORDs on stack, returns EAX=???, ECX nonzero on error
 04h	???
	called with DWORD on stack, returns EAX=???, ECX nonzero on error
 06h	???
	called with DWORD on stack, returns EAX=???, ECX nonzero on error
 07h	???
	called with 3 DWORDs on stack, returns EAX=???, ECX nonzero on error
 0Bh	???
	called with 2 DWORDs on stack, returns EAX=???, ECX nonzero on error
 0Ch	???
	called with 2 DWORDs on stack, returns EAX=???, ECX nonzero on error
 0Dh	???
	called with 6 DWORDs on stack, returns EAX=???, ECX nonzero on error
 1Ah	???
	called with 3 DWORDs on stack
SeeAlso: #01336

INT 20 P - Frontier Technologies ??? - VxD SERVICES
	VxD = 3049h
Note:	the desired VxD and service number are identified by the data
	  immediately following the INT 20 instruction, as in:
		INT	20h
		DW	service number
		DW	VxD identifier
SeeAlso: INT 2F/AX=1684h"DEVICE API",INT 30"Windows",#01265,#01336

(Table 01336)
Values for ??? (VxD ID 3049h) service number:
 00h	get version???
 1Dh	???
	called with 2 DWORDs on stack; returns EAX=???, ECX nonzero on error
 1Eh	???
	called with 6 DWORDs on stack; returns EAX=???, ECX nonzero on error
SeeAlso: #01335

INT 20 P - QEMM - VstlthD - VxD SERVICES
	VxD = 3098h
Note:	the desired VxD and service number are identified by the data
	  immediately following the INT 20 instruction, as in:
		INT	20h
		DW	service number
		DW	VxD identifier
SeeAlso: INT 2F/AX=1684h"DEVICE API",INT 30"Windows",#01265,#01340

(Table 01337)
Values for VStlthD (VxD ID 3098h) service number:
 00h	get version
	Return:	CF clear
		EAX = version (AH = major, AL = BCD minor)
 01h	???
 02h	get current ???
	Return: CF clear
		EDX = current value of ???
 03h	???
SeeAlso: #01334,#01338

INT 20 P - Microsoft Windows - WSVV - VxD SERVICES
	VxD = 30F6h
Note:	the desired VxD and service number are identified by the data
	  immediately following the INT 20 instruction, as in:
		INT	20h
		DW	service number
		DW	VxD identifier
SeeAlso: INT 2F/AX=1684h"DEVICE API",INT 30"Windows",#01265,#01340

(Table 01338)
Values for WSVV (VxD ID 30F6h) service number:
 00h	get WSVV version???
SeeAlso: #01337,#01339

INT 20 P - Microsoft Windows - ASPIENUM - VxD SERVICES
	VxD = 33FCh
Note:	the desired VxD and service number are identified by the data
	  immediately following the INT 20 instruction, as in:
		INT	20h
		DW	service number
		DW	VxD identifier
SeeAlso: INT 2F/AX=1684h"DEVICE API",INT 30"Windows",#01265,#01340

(Table 01339)
Values for ASPIENUM (VxD ID 33FCh) service number:
 00h	get ASPIENUM version???
 01h	???
 02h	???
 03h	???
SeeAlso: #01338,#01340

INT 20 P - Microsoft Windows - DSOUND - VxD SERVICES
	VxD = 357Eh
Note:	the desired VxD and service number are identified by the data
	  immediately following the INT 20 instruction, as in:
		INT	20h
		DW	service number
		DW	VxD identifier
SeeAlso: INT 2F/AX=1684h"DEVICE API",INT 30"Windows",#01265,#01340

(Table 01340)
Values for DSOUND (VxD ID 357Eh) service number:
 00h	get DSOUND version???
 01h	???
 02h	???
SeeAlso: #01339,#01341

INT 20 P - Microsoft Windows - A3D - VxD SERVICES
	VxD = 39E6h
Note:	the desired VxD and service number are identified by the data
	  immediately following the INT 20 instruction, as in:
		INT	20h
		DW	service number
		DW	VxD identifier
SeeAlso: INT 2F/AX=1684h"DEVICE API",INT 30"Windows",#01265,#01340


(Table 01341)
Values for A3D (VxD ID 39E6h) service number:
 00h	get version???
 01h	???
 02h	??? (highest service defined)
SeeAlso: #01340,#01342

INT 20 P - Microsoft Windows - CWCPROXY - VxD SERVICES
	VxD = 3BFDh
Note:	the desired VxD and service number are identified by the data
	  immediately following the INT 20 instruction, as in:
		INT	20h
		DW	service number
		DW	VxD identifier
SeeAlso: INT 2F/AX=1684h"DEVICE API",INT 30"Windows",#01265,#01340

(Table 01342)
Values for CWCPROXY (VxD ID 3BFDh) service number:
 00h	get version???
 ...
 03h	??? (highest service defined)
SeeAlso: #01341,#01343

INT 20 P - Microsoft Windows - VGARTD - VxD SERVICES
	VxD = 3C78h
Note:	the desired VxD and service number are identified by the data
	  immediately following the INT 20 instruction, as in:
		INT	20h
		DW	service number
		DW	VxD identifier
SeeAlso: INT 2F/AX=1684h"DEVICE API",INT 30"Windows",#01265,#01340

(Table 01343)
Values for VGARTD (VxD ID 3C78h) service number:
 00h	get version???
 ...
 05h	??? (highest service defined)
SeeAlso: #01342,#02642

INT 21 - COMTROL HOSTESS i/ISA DEBUGGER - GET SEGMENT FOR CONTROL PROGRAM USE
	???
Return: AX = first segment available for control program use
SeeAlso: INT 20"COMTROL",INT 22"COMTROL"

INT 21 - DOS 1+ - TERMINATE PROGRAM
	AH = 00h
	CS = PSP segment
Notes:	Microsoft recommends using INT 21/AH=4Ch for DOS 2+
	this function sets the program's return code (ERRORLEVEL) to 00h
	execution continues at the address stored in INT 22 after DOS performs
	  whatever cleanup it needs to do (restoring the INT 22,INT 23,INT 24
	  vectors from the PSP assumed to be located at offset 0000h in the
	  segment indicated by the stack copy of CS, etc.)
	if the PSP is its own parent, the process's memory is not freed; if
	  INT 22 additionally points into the terminating program, the
	  process is effectively NOT terminated
	not supported by MS Windows 3.0 DOSX.EXE DOS extender
SeeAlso: AH=26h,AH=31h,AH=4Ch,INT 20,INT 22

INT 21 - DOS 1+ - READ CHARACTER FROM STANDARD INPUT, WITH ECHO
	AH = 01h
Return: AL = character read
Notes:	^C/^Break are checked, and INT 23 executed if read
	^P toggles the DOS-internal echo-to-printer flag
	^Z is not interpreted, thus not causing an EOF if input is redirected
	character is echoed to standard output
	standard input is always the keyboard and standard output the screen
	  under DOS 1.x, but they may be redirected under DOS 2+
SeeAlso: AH=06h,AH=07h,AH=08h,AH=0Ah

INT 21 - VIRUS - "Susan" - INSTALLATION CHECK
	AX = 010Fh
Return: AX = 7553h ("Su") if resident
SeeAlso: INT 16/AH=DDh"VIRUS",INT 21/AX=0B56h

INT 21 - DOS 1+ - WRITE CHARACTER TO STANDARD OUTPUT
	AH = 02h
	DL = character to write
Return: AL = last character output (despite the official docs which state
		nothing is returned) (at least DOS 2.1-7.0)
Notes:	^C/^Break are checked, and INT 23 executed if pressed
	standard output is always the screen under DOS 1.x, but may be
	  redirected under DOS 2+
	the last character output will be the character in DL unless DL=09h
	  on entry, in which case AL=20h as tabs are expanded to blanks
	if standard output is redirected to a file, no error checks (write-
	  protected, full media, etc.) are performed
SeeAlso: AH=06h,AH=09h

INT 21 - DOS 1+ - READ CHARACTER FROM STDAUX
	AH = 03h
Return: AL = character read
Notes:	keyboard checked for ^C/^Break, and INT 23 executed if detected
	STDAUX is usually the first serial port
SeeAlso: AH=04h,INT 14/AH=02h,INT E0/CL=03h

INT 21 - DOS 1+ - WRITE CHARACTER TO STDAUX
	AH = 04h
	DL = character to write
Notes:	keyboard checked for ^C/^Break, and INT 23 executed if detected
	STDAUX is usually the first serial port
	if STDAUX is busy, this function will wait until it becomes free
SeeAlso: AH=03h,INT 14/AH=01h,INT E0/CL=04h

INT 21 - DOS 1+ - WRITE CHARACTER TO PRINTER
	AH = 05h
	DL = character to print
Notes:	keyboard checked for ^C/^Break, and INT 23 executed if detected
	STDPRN is usually the first parallel port, but may be redirected under
	  DOS 2+
	if the printer is busy, this function will wait
SeeAlso: INT 17/AH=00h

INT 21 - DOS 1+ - DIRECT CONSOLE OUTPUT
	AH = 06h
	DL = character (except FFh)
Return: AL = character output (despite official docs which state nothing is
		returned) (at least DOS 2.1-7.0)
Notes:	does not check ^C/^Break
	writes to standard output, which is always the screen under DOS 1.x,
	  but may be redirected under DOS 2+
SeeAlso: AH=02h,AH=09h

INT 21 - DOS 1+ - DIRECT CONSOLE INPUT
	AH = 06h
	DL = FFh
Return: ZF set if no character available
	    AL = 00h
	ZF clear if character available
	    AL = character read
Notes:	^C/^Break are NOT checked
	if the returned character is 00h, the user pressed a key with an
	  extended keycode, which will be returned by the next call of this
	  function
	this function reads from standard input, which is always the keyboard
	  under DOS 1.x, but may be redirected under DOS 2+
	although the return of AL=00h when no characters are available is not
	  documented, some programs rely on this behavior
SeeAlso: AH=0Bh

INT 21 - DOS 1+ - DIRECT CHARACTER INPUT, WITHOUT ECHO
	AH = 07h
Return: AL = character read from standard input
Notes:	does not check ^C/^Break
	standard input is always the keyboard under DOS 1.x, but may be
	  redirected under DOS 2+
	if the interim console flag is set (see AX=6301h), partially-formed
	  double-byte characters may be returned
SeeAlso: AH=01h,AH=06h,AH=08h,AH=0Ah

INT 21 - DOS 1+ - CHARACTER INPUT WITHOUT ECHO
	AH = 08h
Return: AL = character read from standard input
Notes:	^C/^Break are checked, and INT 23 executed if detected
	standard input is always the keyboard under DOS 1.x, but may be
	  redirected under DOS 2+
	if the interim console flag is set (see AX=6301h), partially-formed
	  double-byte characters may be returned
SeeAlso: AH=01h,AH=06h,AH=07h,AH=0Ah,AH=64h"DOS 3.2+"

INT 21 - DOS 1+ - WRITE STRING TO STANDARD OUTPUT
	AH = 09h
	DS:DX -> '$'-terminated string
Return: AL = 24h (the '$' terminating the string, despite official docs which
		state that nothing is returned) (at least DOS 2.1-7.0 and
		NWDOS)
Notes:	^C/^Break are checked, and INT 23 is called if either pressed
	standard output is always the screen under DOS 1.x, but may be
	  redirected under DOS 2+
	under the FlashTek X-32 DOS extender, the pointer is in DS:EDX
SeeAlso: AH=02h,AH=06h"OUTPUT"

INT 21 - DOS 1+ - BUFFERED INPUT
	AH = 0Ah
	DS:DX -> buffer (see #01344)
Return: buffer filled with user input
Notes:	^C/^Break are checked, and INT 23 is called if either detected
	reads from standard input, which may be redirected under DOS 2+
	if the maximum buffer size (see #01344) is set to 00h, this call returns
	  immediately without reading any input
SeeAlso: AH=0Ch,INT 2F/AX=4810h

Format of DOS input buffer:
Offset	Size	Description	(Table 01344)
 00h	BYTE	maximum characters buffer can hold
 01h	BYTE	(call) number of chars from last input which may be recalled
		(ret) number of characters actually read, excluding CR
 02h  N BYTEs	actual characters read, including the final carriage return

INT 21 - WCED v1.6+ - INSTALLATION CHECK
	AX = 0A00h
	DS:DX -> 6-byte buffer whose first two bytes must be 00h
Return: buffer offset 02h-05h filled with "Wced" if installed
Program: WCED is a free command-line editor and history utility by Stuart
	  Russell
SeeAlso: AH=FFh"CED"

INT 21 - DOS 1+ - GET STDIN STATUS
	AH = 0Bh
Return: AL = status
	    00h if no character available
	    FFh if character is available
Notes:	^C/^Break are checked, and INT 23 is called if either pressed
	standard input is always the keyboard under DOS 1.x, but may be
	  redirected under DOS 2+
	if the interim console flag is set (see AX=6301h), this function
	  returns AL=FFh if a partially-formed double-byte character is
	  available
SeeAlso: AH=06h"INPUT",AX=4406h

INT 21 - VIRUS - "Perfume" - INSTALLATION CHECK
	AX = 0B56h
Return: AX = 4952h if resident
SeeAlso: AX=0D20h,INT 12/AX=4350h/BX=4920h,INT 13/AH=F2h,INT 21/AX=010Fh

INT 21 - DOS 1+ - FLUSH BUFFER AND READ STANDARD INPUT
	AH = 0Ch
	AL = STDIN input function to execute after flushing buffer
	other registers as appropriate for the input function
Return: as appropriate for the specified input function
Note:	if AL is not one of 01h,06h,07h,08h, or 0Ah, the buffer is flushed but
	  no input is attempted
SeeAlso: AH=01h,AH=06h"INPUT",AH=07h,AH=08h,AH=0Ah

INT 21 - DOS 1+ - DISK RESET
	AH = 0Dh
Return: (DOS 6 only) CF clear (earlier versions preserve CF)
Notes:	This function writes all modified disk buffers to disk, but does not
	  update the directory information (that is only done when files are
	  closed or a SYNC call is issued)
SeeAlso: AX=5D01h,AX=710Dh,INT 13/AH=00h,INT 2F/AX=1120h

INT 21 - VIRUS - "Crazy Imp" - INSTALLATION CHECK
	AX = 0D20h
Return: AX = 1971h if resident
SeeAlso: AX=0B56h,AX=1812h,AX=2C2Ch,AX=710Dh,AH=30h/DX=ABCDh

INT 21 - DOS 1+ - SELECT DEFAULT DRIVE
	AH = 0Eh
	DL = new default drive (00h = A:, 01h = B:, etc)
Return: AL = number of potentially valid drive letters
Notes:	under Novell NetWare, the return value is always 32, the number of
	  drives that NetWare supports
	under DOS 3.0+, the return value is the greatest of 5, the value of
	  LASTDRIVE= in CONFIG.SYS, and the number of drives actually present
	on a DOS 1.x/2.x single-floppy system, AL returns 2 since the floppy
	  may be accessed as either A: or B:
	otherwise, the return value is the highest drive actually present
	DOS 1.x supports a maximum of 16 drives, 2.x a maximum of 63 drives,
	  and 3+ a maximum of 26 drives
	under Novell DOS 7, this function returns the correct LASTDRIVE value
	  even when the undocumented LASTDRIVE=27..32 directive was used in
	  CONFIG.SYS
	"parse FCB" (see AH=29h) can be used to determine whether a drive
	  letter is valid
SeeAlso: AH=19h,AH=3Bh,AH=DBh

INT 21 U - Novell DOS 7 - SDRes v27.03 - INSTALLATION CHECK
	AH = 0Eh
	DL = ADh
Return: AL = BAh if installed
Program: SDRes is the resident portion of the Search&Destroy antiviral by
	  Fifth Generation Systems, as bundled with Novell DOS 7
Note:	SDRes will terminate programs which test for the presence of viruses
	  using interrupt-based installation calls, saying that the program
	  may be infected
SeeAlso: AH=0Eh/DL=AEh,AH=0Eh/DL=AFh,AH=4Ah/BX=00B6h,INT 13/AX=A759h

INT 21 U - Novell DOS 7 - SDRes v27.03 - CLEAR ??? FLAG
	AH = 0Eh
	DL = AEh
SeeAlso: AH=0Eh/DL=ADh,AH=0Eh/DL=AFh,INT 13/AX=A759h

INT 21 U - Novell DOS 7 - SDRes v27.03 - SET ??? FLAG
	AH = 0Eh
	DL = AFh
SeeAlso: AH=0Eh/DL=ADh,AH=0Eh/DL=AEh,INT 13/AX=A759h

INT 21 - DOS 1+ - OPEN FILE USING FCB
	AH = 0Fh
	DS:DX -> unopened File Control Block (see #01345,#01346)
Return: AL = status
	    00h successful
	    FFh file not found or access denied
Notes:	(DOS 3.1+) file opened for read/write in compatibility mode
	an unopened FCB has the drive, filename, and extension fields filled
	  in and all other bytes cleared
	not supported by MS Windows 3.0 DOSX.EXE DOS extender
	DR DOS checks password attached with AX=4303h
	(FAT32 drive) this function will only succeed for creating a volume
	  label; FAT32 does not support FCBs for file I/O
BUG:	APPEND for DOS 3.3+ corrupts DX if the file is not found
SeeAlso: AH=10h,AH=16h,AH=3Dh,AX=4303h

Format of File Control Block:
Offset	Size	Description	(Table 01345)
 00h	BYTE	drive number (0 = default, 1 = A, etc)
		FFh is not allowed (signals extended FCB, see #01346)
 01h  8 BYTEs	blank-padded file name
 09h  3 BYTEs	blank-padded file extension
 0Ch	WORD	current block number
 0Eh	WORD	logical record size
 10h	DWORD	file size
 14h	WORD	date of last write (see #01666 at AX=5700h)
 16h	WORD	time of last write (see #01665 at AX=5700h) (DOS 1.1+)
 18h  8 BYTEs	reserved (see #01347,#01348,#01349,#01350,#01351)
 20h	BYTE	record within current block
 21h	DWORD	random access record number (if record size is > 64 bytes, high
		  byte is omitted)
SeeAlso: #01346

Format of Extended File Control Block (XFCB):
Offset	Size	Description	(Table 01346)
 00h	BYTE	FFh signature for extended FCB
 01h  5 BYTEs	reserved
 06h	BYTE	file attribute if extended FCB
 07h 36 BYTEs	standard FCB (all offsets are shifted by seven bytes)
SeeAlso: #01246

Format of FCB reserved field for DOS 1.0:
Offset	Size	Description	(Table 01347)
 16h	WORD	location in directory (if high byte = FFh, low byte is device
		  ID)
 18h	WORD	number of first cluster in file
 1Ah	WORD	current absolute cluster number on disk
 1Ch	WORD	current relative cluster number within file
		(0 = first cluster of file, 1 = second cluster, etc.)
 1Eh	BYTE	dirty flag (00h = not dirty)
 1Fh	BYTE	unused

Format of FCB reserved field for DOS 1.10-1.25:
Offset	Size	Description	(Table 01348)
 18h	BYTE	bit 7: set if logical device
		bit 6: not dirty
		bits 5-0: disk number or logical device ID
 19h	WORD	starting cluster number on disk
 1Bh	WORD	current absolute cluster number on disk
 1Dh	WORD	current relative cluster number within file
 1Fh	BYTE	unused

Format of FCB reserved field for DOS 2.x:
Offset	Size	Description	(Table 01349)
 18h	BYTE	bit 7: set if logical device
		bit 6: set if open???
		bits 5-0: ???
 19h	WORD	starting cluster number on disk
 1Bh	WORD	???
 1Dh	BYTE	???
 1Eh	BYTE	???
 1Fh	BYTE	???

Format of FCB reserved field for DOS 3.x:
Offset	Size	Description	(Table 01350)
 18h	BYTE	number of system file table entry for file
 19h	BYTE	attributes
		bits 7,6: 00 = SHARE.EXE not loaded, disk file
			  01 = SHARE.EXE not loaded, character device
			  10 = SHARE.EXE loaded, remote file
			  11 = SHARE.EXE loaded, local file or device
		bits 5-0: low six bits of device attribute word
---SHARE.EXE loaded, local file---
 1Ah	WORD	starting cluster of file on disk
 1Ch	WORD	(DOS 3.x) offset within SHARE of sharing record
		  (see #01637 at AH=52h)
 1Eh	BYTE	file attribute
 1Fh	BYTE	???
---SHARE.EXE loaded, remote file---
 1Ah	WORD	number of sector containing directory entry (see #01352)
 1Ch	WORD	relative cluster within file of last cluster accessed
 1Eh	BYTE	absolute cluster number of last cluster accessed
 1Fh	BYTE	???
---SHARE.EXE not loaded---
 1Ah	BYTE	(low byte of device attribute word AND 0Ch) OR open mode
 1Bh	WORD	starting cluster of file
 1Dh	WORD	number of sector containing directory entry (see #01352)
 1Fh	BYTE	number of directory entry within sector
Note:	if FCB opened on character device, DWORD at 1Ah is set to the address
	  of the device driver header, then the BYTE at 1Ah is overwritten.
SeeAlso: #01646

Format of FCB reserved field for DOS 5.0:
Offset	Size	Description	(Table 01351)
 18h	BYTE	number of system file table entry for file
 19h	BYTE	attributes
		bits 7,6: 00 = SHARE.EXE not loaded, disk file
			  01 = SHARE.EXE not loaded, character device
			  10 = SHARE.EXE loaded, remote file
			  11 = SHARE.EXE loaded, local file or device
		bits 5-0: low six bits of device attribute word
---SHARE.EXE loaded, local file---
 1Ah	WORD	starting cluster of file on disk
 1Ch	WORD	unique sequence number of sharing record
 1Eh	BYTE	file attributes
 1Fh	BYTE	unused???
---SHARE.EXE loaded, remote file---
 1Ah	WORD	network handle
 1Ch	DWORD	network ID
---SHARE not loaded, local device---
 1Ah	DWORD	pointer to device driver header (see #01646)
 1Eh  2 BYTEs	unused???
---SHARE not loaded, local file---
 1Ah	BYTE	extra info
		bit 7: read-only attribute from SFT
		bit 6: archive attribute from SFT
		bits 5-0: high bits of sector number
 1Bh	WORD	starting cluster of file
 1Dh	WORD	low word of sector number containing directory entry
		(see #01352)
 1Fh	BYTE	number of directory entry within sector

INT 21 - DOS 1+ - CLOSE FILE USING FCB
	AH = 10h
	DS:DX -> File Control Block (see #01345)
Return: AL = status
	    00h successful
	    FFh failed
Notes:	a successful close forces all disk buffers used by the file to be
	  written and the directory entry to be updated
	not supported by MS Windows 3.0 DOSX.EXE DOS extender
SeeAlso: AH=0Fh,AH=16h,AH=3Eh

INT 21 - DOS 1+ - FIND FIRST MATCHING FILE USING FCB
	AH = 11h
	DS:DX -> unopened FCB (see #01345), may contain '?' wildcards
Return: AL = status
	    00h successful
		[DTA] unopened FCB for first matching file
	    FFh no matching filename, or bad FCB
Notes:	the type of the returned FCB depends on whether the input FCB was a
	  normal or an extended FCB
	the data returned in the DTA (disk transfer area) is actually the
	  drive number (or extended FCB header and drive number) followed by
	  the file's directory entry (see #01352); this format happens to be
	  compatible with an unopened FCB
	for extended FCBs with search attribute 08h, the volume label (if any)
	  will be returned even if the current directory is not the root dir.
	DOS 3.0+ also allows the '*' wildcard
	the search FCB at DS:DX must not be modified if AH=12h will be used to
	  continue searching; DOS 3.3 has set the following parts of the FCB:
		 0Ch	BYTE	???
		 0Dh	WORD	directory entry number of matching file
		 0Fh	WORD	cluster number of current directory
		 11h  4 BYTEs	???
		 15h	BYTE	drive number (1=A:)
	this function is used by many copy protection schemes to obtain the
	  starting cluster of a file
BUG:	under Windows95, if a .EXE program ("MZ" header) rather than a true
	  .COM calls this function from a DOS box, the ten bytes of the
	  directory entry from 0Ch to 15h may be filled with zeros rather than
	  the additional file times
SeeAlso: AH=12h,AH=1Ah,AH=4Eh,INT 2F/AX=111Bh

Format of DOS directory entry:
Offset	Size	Description	(Table 01352)
 00h  8 BYTEs	blank-padded filename
		first character is set to E5h for deleted files (05h for
		  pending delete files under Novell DOS / OpenDOS)
 08h  3 BYTEs	blank-padded file extension
 0Bh	BYTE	attributes
 0Ch 10 BYTEs	(MS-DOS 1.0-6.22) reserved
		(DR DOS) used to store file password / owner (see #01354)
			(see also INT 21/AX=4302h)
		(Novell DOS 7) DELWATCH data (see #01354)
		(MS-DOS 7/Windows95) additional file times (see #01353)
 16h	WORD	time of creation or last update (see #01665 at AX=5700h)
 18h	WORD	date of creation or last update (see #01666 at AX=5700h)
 1Ah	WORD	starting cluster number (see also AX=440Dh/CX=0871h)
		(may not be set in INT 21/AH=11h return data for FAT32 drives)
 1Ch	DWORD	file size
SeeAlso: #01355,#02628,#02629

Format of MS-DOS 7/Windows95 additional file times:
Offset	Size	Description	(Table 01353)
 00h	BYTE	reserved
 01h	BYTE	10-millisecond units past creation time below
 02h	WORD	file creation time
 04h	WORD	file creation date
 06h	WORD	last-access date
 08h	WORD	(FAT32) high word of starting cluster number
Note:	this data is stored beginning at offset 0Ch in a standard directory
	  entry
SeeAlso: #01352

Format of DR DOS 6/Novell DOS 7 additional file information:
Offset	Size	Description	(Table 01354)
 0Ch	BYTE	reserved (00h)
		(DOSPLUS v1.2) user-defined attributes for CP/M compatibility
		  (bit 7 = F1,...,bit 4 = F4, bits 3-0 reserved (0))
 0Dh	BYTE	first character of original filename for deleted file
 0Eh	WORD	encrypted file/directory password
 10h	WORD	reserved (00h)
		(Novell DOS 7 DELWATCH) original file time
		    cleared when file is undeleted or purged
 12h	WORD	(DR DOS 6) file owner ID
		(Novell DOS 7 DELWATCH) original file date
		    cleared when file is undeleted or purged
 14h	WORD	single/multiuser file/directory access rights (see AX=4302h)
---deleted files---
 16h	WORD	(Novell DOS 7 DELWATCH) time of deletion
 18h	WORD	(Novell DOS 7 DELWATCH) date of deletion
Note:	offsets are within the full directory entry
SeeAlso: #01352

Format of MS-DOS 7/Windows95 long-filename directory entry:
Offset	Size	Description	(Table 01355)
 00h	BYTE	LFN record sequence and flags
		bits 5-0: sequence number
		bit 6: set if last long-filename record for file
		bit 7: set if file deleted
 01h 10 BYTEs	long filename, first part
 0Bh	BYTE	0Fh (otherwise impossible file attribute, used as signature)
 0Ch	BYTE	reserved??? (00h)
 0Dh	BYTE	checksum for short filename
 0Eh 12 BYTEs	long filename, second part
 1Ah	WORD	first cluster number (always 0000h for LFN records)
 1Ch  4 BYTEs	long filename, third part
Notes:	long-filename entries are always stored in the directory just prior
	  to the short-name entry for a file
	multiple LFN records are used if the long filename does not fit into
	  a single record
	the short-filename checksum byte is computed by adding up the
	  eleven bytes of the short filename, rotating the intermediate
	  sum right one bit before adding the next character
	the long filename is encoded as 16-bit Unicode characters; for most
	  filenames, this appears in the directory as the ASCII character
	  followed by 00h
SeeAlso: #01352,INT 21/AX=5704h,INT 21/AH=71h

INT 21 - DOS 1+ - FIND NEXT MATCHING FILE USING FCB
	AH = 12h
	DS:DX -> unopened FCB (see #01345)
Return: AL = status
	    00h successful
		Disk Transfer Area filled with unopened FCB
	    FFh no more matching filenames
Note:	(see AH=11h)
	assumes that successful FindFirst executed on search FCB before call
SeeAlso: AH=1Ah,AH=4Fh,INT 2F/AX=111Ch

INT 21 - DOS 1+ - DELETE FILE USING FCB
	AH = 13h
	DS:DX -> unopened FCB (see #01345), filename filled with template for
		deletion ('?' wildcards allowed)
Return: AL = status
	    00h one or more files successfully deleted
	    FFh no matching files or all were read-only or locked
Notes:	DOS 1.25+ deletes everything in the current directory (including
	  subdirectories) and sets the first byte of the name to 00h (entry
	  never used) instead of E5h if called on an extended FCB with
	  filename '???????????' and bits 0-4 of the attribute set (bits 1 and
	  2 for DOS 1.x).  This may have originally been an optimization to
	  minimize directory searching after a mass deletion (DOS 1.25+ stop
	  the directory search upon encountering a never-used entry), but can
	  corrupt the filesystem under DOS 2+ because subdirectories are
	  removed without deleting the files they contain.
	currently-open files should not be deleted
	MS-DOS allows deletion of read-only files with an extended FCB, whereas
	  Novell NetWare, DR DOS 6, and Novell DOS 7/OpenDOS 7.01 do not
	this function generates a trap "D" under OS/2 v4.x (Warp4) when called
	  on an HPFS partition with a wildcard in the filename; it operates
	  correctly on FAT partitions and when called without wildcards
SeeAlso: AH=41h,INT 2F/AX=1113h

INT 21 - DOS 1+ - SEQUENTIAL READ FROM FCB FILE
	AH = 14h
	DS:DX -> opened FCB (see #01345)
Return: AL = status
	    00h successful
	    01h end of file (no data)
	    02h segment wrap in DTA
	    03h end of file, partial record read
	Disk Tranfer Area filled with record read from file
Notes:	reads a record of the size specified in the FCB beginning at the
	  current file position, then updates the current block and current
	  record fields in the FCB
	if a partial record was read, it is zero-padded to the full size
	not supported by MS Windows 3.0 DOSX.EXE DOS extender
SeeAlso: AH=0Fh,AH=15h,AH=1Ah,AH=3Fh"DOS",INT 2F/AX=1108h

INT 21 - DOS 1+ - SEQUENTIAL WRITE TO FCB FILE
	AH = 15h
	DS:DX -> opened FCB (see #01345)
	Disk Tranfer Area contains record to be written
Return: AL = status
	    00h successful
	    01h disk full
	    02h segment wrap in DTA
Notes:	writes a record of the size specified in the FCB beginning at the
	  current file position, then updates the current block and current
	  record fields in the FCB
	if less than a full sector is written, the data is placed in a DOS
	  buffer to be written out at a later time
	not supported by MS Windows 3.0 DOSX.EXE DOS extender
SeeAlso: AH=0Fh,AH=14h,AH=1Ah,AH=40h,INT 2F/AX=1109h

INT 21 - DOS 1+ - CREATE OR TRUNCATE FILE USING FCB
	AH = 16h
	DS:DX -> unopened FCB (see #01345), wildcards not allowed
Return: AL = status
	    00h successful
	    FFh directory full or file exists and is read-only or locked
Notes:	if file already exists, it is truncated to zero length
	if an extended FCB is used, the file is given the attribute in the
	  FCB; this is how to create a volume label in the disk's root dir
	not supported by MS Windows 3.0 DOSX.EXE DOS extender
	(FAT32 drive) this function will only succeed for creating a volume
	  label; FAT32 does not support FCBs for file I/O
SeeAlso: AH=0Fh,AH=10h,AH=3Ch

INT 21 - DOS 1+ - RENAME FILE USING FCB
	AH = 17h
	DS:DX -> modified FCB (see also #01345)
		the old filename ('?' wildcards OK) is in the standard location
		while the new filename ('?' wildcards OK, no drive) is stored
		in the 11 bytes beginning at offset 11h
Return: AL = status
	    00h successfully renamed
	    FFh no matching files,file is read-only, or new name already exists
Notes:	subdirectories may be renamed using an extended FCB with the
	  appropriate attribute, as may volume labels
	DR DOS checks password attached with AX=4303h before permitting rename
SeeAlso: AH=0Fh,AH=13h,AX=4303h,AH=56h,INT 2F/AX=1111h

INT 21 - DOS 1+ - NULL FUNCTION FOR CP/M COMPATIBILITY
	AH = 18h
Return: AL = 00h
Note:	corresponds to the CP/M BDOS function "get bit map of logged drives",
	  which is meaningless under MS-DOS
SeeAlso: AH=1Dh,AH=1Eh,AH=20h,AX=4459h,INT 60/DI=0513h

INT 21 - U - PTS-DOS 6.51 & S/DOS 1.0 - EXTENDED RENAME FILE USING FCB
	AH = 18h
	DS:DX -> modified FCB (see also #01345)
Return: AL = status
	     00h successfully renamed
	     FFh no matching files,file is read-only, or new name already exists
Notes:	This function is provided by Paragon Technology Systems S/DOS 1.0
	  (and most probably also PTS-DOS 6.51, maybe even earlier). It uses
	  the same code as for function INT 21/AH=17h, but additionally sets
	  an internal "SERVER" flag on entry. Apparently this results in
	  different usage of attributes and wildcards.
	It is currently unknown if this function is also supported by
	  PhysTechSoft's PTS-DOS 6.60, 6.70, or 2000.
SeeAlso: AH=17h,AH=0Fh,AH=13h,AX=4303h,AH=56h,INT 2F/AX=1111h,INT21/AH=5Dh

INT 21 - VIRUS - "Tasha Yar" - INSTALLATION CHECK
	AX = 1812h
Return: AL = 00h if resident
	DX = 4310h if resident
SeeAlso: INT 21/AX=0B56h"VIRUS",INT 21/AX=187Fh,INT 21/AX=2C2Ch"VIRUS"

INT 21 - VIRUS - "DS-3783" -INSTALLATION CHECK
	AX = 187Fh
	BX = 4453h
Return: BX = 87A1h if resident
SeeAlso: AX=1812h"VIRUS",AX=18FFh"VIRUS"

INT 21 - VIRUS - "Pathogen:SMEG" - INSTALLATION CHECK
	AX = 18FFh
Return: AX = E701h if resident
SeeAlso: INT 21/AX=1812h"VIRUS",INT 21/AX=2080h"VIRUS"

INT 21 - DOS 1+ - GET CURRENT DEFAULT DRIVE
	AH = 19h
Return: AL = drive (00h = A:, 01h = B:, etc)
Note:	Novell NetWare uses the fact that DOS 2.x COMMAND.COM issues this call
	  from a particular location every time it starts a command to
	  determine when to issue an automatic EOJ
SeeAlso: AH=0Eh,AH=47h,AH=BBh

INT 21 - DOS 1+ - SET DISK TRANSFER AREA ADDRESS
	AH = 1Ah
	DS:DX -> Disk Transfer Area (DTA)
Notes:	the DTA is set to PSP:0080h when a program is started
	under the FlashTek X-32 DOS extender, the pointer is in DS:EDX
SeeAlso: AH=11h,AH=12h,AH=2Fh,AH=4Eh,AH=4Fh

INT 21 - DOS 1+ - GET ALLOCATION INFORMATION FOR DEFAULT DRIVE
	AH = 1Bh
Return: AL = sectors per cluster (allocation unit)
	CX = bytes per sector
	DX = total number of clusters
	DS:BX -> media ID byte (see #01356)
Notes:	under DOS 1.x, DS:BX points at an actual copy of the FAT; later
	  versions return a pointer to a copy of the FAT's ID byte
	this function may not be properly supported on CD-ROMs and other
	  installable file systems (use AX=4402h"CD-ROM" for CD-ROMs
	  instead)
BUG:	DOS 7.10 (Win95B/Win98) reportedly returns incorrect values in AL and
	  DX for FAT12/FAT16 drives, even though it manages correct results
	  for FAT32 drives (DOS windows are not affected, only real-mode
	  DOS)
SeeAlso: AH=1Ch,AH=36h

(Table 01356)
Values for media ID byte:
 FFh	floppy, double-sided, 8 sectors per track (320K)
 FEh	floppy, single-sided, 8 sectors per track (160K)
 FDh	floppy, double-sided, 9 sectors per track (360K)
 FCh	floppy, single-sided, 9 sectors per track (180K)
 FAh	HP 200LX D: ROM disk, 16 sectors per track (995K)
	HP 200LX E: (Stacker host drive ???)
 F9h	floppy, double-sided, 15 sectors per track (1.2M)
	floppy, double-sided, 9 sectors per track (720K,3.5")
 F8h	hard disk
 F0h	other media
	(e.g. floppy, double-sized, 18 sectors per track -- 1.44M,3.5")

INT 21 - DOS 1+ - GET ALLOCATION INFORMATION FOR SPECIFIC DRIVE
	AH = 1Ch
	DL = drive (00h = default, 01h = A:, etc)
Return: AL = sectors per cluster (allocation unit), or FFh if invalid drive
	CX = bytes per sector
	DX = total number of clusters
	DS:BX -> media ID byte (see #01356)
Notes:	under DOS 1.x, DS:BX points at an actual copy of the FAT; later
	  versions return a pointer to a copy of the FAT's ID byte
	on a DBLSPACE drive, the total number of clusters is based on the
	  estimated compression ratio
	this function may not be properly supported on CD-ROMs and other
	  installable file systems (use AX=4402h"CD-ROM" for CD-ROMs
	  instead)
BUG:	DOS 7.10 (Win95B/Win98) reportedly returns incorrect values in AL and
	  DX for FAT12/FAT16 drives, even though it manages correct results
	  for FAT32 drives (DOS windows are not affected, only real-mode
	  DOS)
SeeAlso: AH=1Bh,AH=36h

INT 21 - DOS 1+ - NULL FUNCTION FOR CP/M COMPATIBILITY
	AH = 1Dh
Return: AL = 00h
Note:	corresponds to the CP/M BDOS function "get bit map of read-only
	  drives", which is meaningless under MS-DOS
SeeAlso: AH=18h,AH=1Eh,AH=20h,AX=4459h

INT 21 - DOS 1+ - NULL FUNCTION FOR CP/M COMPATIBILITY
	AH = 1Eh
Return: AL = 00h
Note:	corresponds to the CP/M BDOS function "set file attributes" which was
	 meaningless under MS-DOS 1.x
SeeAlso: AH=18h,AH=1Dh,AH=20h

INT 21 - DOS 1+ - GET DRIVE PARAMETER BLOCK FOR DEFAULT DRIVE
	AH = 1Fh
Return: AL = status
	    00h successful
		DS:BX -> Drive Parameter Block (DPB) (see #01357 for DOS 1.x,
			AH=32h for DOS 2+)
	    FFh invalid drive
Note:	this call was undocumented prior to the release of DOS 5.0; however,
	  only the DOS 4.0+ version of the DPB has been documented
SeeAlso: AH=32h,AX=7302h

Format of DOS 1.1 and MS-DOS 1.25 drive parameter block:
Offset	Size	Description	(Table 01357)
 00h	BYTE	sequential device ID
 01h	BYTE	logical drive number (0=A:)
 02h	WORD	bytes per sector
 04h	BYTE	highest sector number within a cluster
 05h	BYTE	shift count to convert clusters into sectors
 06h	WORD	starting sector number of first FAT
 08h	BYTE	number of copies of FAT
 09h	WORD	number of directory entries
 0Bh	WORD	number of first data sector
 0Dh	WORD	highest cluster number (number of data clusters + 1)
 0Fh	BYTE	sectors per FAT
 10h	WORD	starting sector of directory
 12h	WORD	address of allocation table
Note:	the DOS 1.0 table is the same except that the first and last fields
	  are missing; see INT 21/AH=32h for the DOS 2+ version
SeeAlso: #01395,#04039

INT 21 - DOS 1+ - NULL FUNCTION FOR CP/M COMPATIBILITY
	AH = 20h
Return: AL = 00h
Note:	corresponds to the CP/M BDOS function "get/set default user
	  (sublibrary) number", which is meaningless under MS-DOS
SeeAlso: AH=18h,AH=1Dh,AH=1Eh,AX=4459h

INT 21 - S/DOS 1.0+ & PTS-DOS 6.51+ - GET OEM REVISION
	AH = 20h
	AL = which OEM code to retrieve
	    00h get PTS OEM code
		Return: CF cleared
			AL = OEM code (currently always 00h)
	    01h get PTS OEM revision code
		Return: CF cleared
			AL = revision code (default is 00h, but may vary)
Desc:	S/DOS is a reduced and modified PTS-DOS 6.51 release with source code
	  on CD
Note:	This function is provided by S/DOS 1.0 (and is most probably also
	  supported with PTS-DOS 6.51+, maybe even earlier).  It clears the
	  CF flag for all other AL arguments, too. However, AL = 00h and 01h
	  are handled separately. The revision code can be individually defined
	  in the MAKEFILE at compilation time.
	The PTS OEM code does not correlate with the DOS OEM code returned
	  by INT 21/AH=30h, likewise the PTS OEM revision does not correlate
	  with the DOS revision returned by INT 21/AX=3306h.
SeeAlso: INT 21/AH=30h,INT 21/AX=3306h

INT 21 - VIRUS - "New-Year" - INSTALLATION CHECK
	AX = 2080h
Return: AH = 00h if resident (normal DOS return would be AX = 2000h)
SeeAlso: INT 21/AX=18FFh"VIRUS",INT 21/AX=2C2Ch"VIRUS"

INT 21 - DOS 1+ - READ RANDOM RECORD FROM FCB FILE
	AH = 21h
	DS:DX -> opened FCB (see #01345)
Return: AL = status
	    00h successful
	    01h end of file, no data read
	    02h segment wrap in DTA, no data read
	    03h end of file, partial record read
	Disk Tranfer Area filled with record read from file
Notes:	the record is read from the current file position as specified by the
	  random record and record size fields of the FCB
	the file position is not updated after reading the record
	if a partial record is read, it is zero-padded to the full size
	not supported by MS Windows 3.0 DOSX.EXE DOS extender
SeeAlso: AH=14h,AH=22h,AH=27h,AH=3Fh"DOS"

INT 21 - DOS 1+ - WRITE RANDOM RECORD TO FCB FILE
	AH = 22h
	DS:DX -> opened FCB (see #01345)
	Disk Transfer Area contains record to be written
Return: AL = status
	    00h successful
	    01h disk full
	    02h segment wrap in DTA
Notes:	the record is written to the current file position as specified by the
	  random record and record size fields of the FCB
	the file position is not updated after writing the record
	if the record is located beyond the end of the file, the file is
	  extended but the intervening data remains uninitialized
	if the record only partially fills a disk sector, it is copied to a
	  DOS disk buffer to be written out to disk at a later time
	not supported by MS Windows 3.0 DOSX.EXE DOS extender
SeeAlso: AH=15h,AH=21h,AH=28h,AH=40h

INT 21 - DOS 1+ - GET FILE SIZE FOR FCB
	AH = 23h
	DS:DX -> unopened FCB (see #01345), wildcards not allowed
Return: AL = status
	    00h successful (matching file found)
		FCB random record field filled with size in records, rounded up
		to next full record
	    FFh failed (no matching file found)
Notes:	not supported by MS Windows 3.0 DOSX.EXE DOS extender
	MS-DOS returns nonsense if the FCB record number field is set to a very
	  large positive number, and status FFh if negative; DR DOS returns the
	  correct file size in both cases
BUG:	APPEND for DOS 3.3+ corrupts DX if the file is not found
SeeAlso: AH=42h

INT 21 - DOS 1+ - SET RANDOM RECORD NUMBER FOR FCB
	AH = 24h
	DS:DX -> opened FCB (see #01345)
Notes:	computes the random record number corresponding to the current record
	  number and record size, then stores the result in the FCB
	normally used when switching from sequential to random access
	not supported by MS Windows 3.0 DOSX.EXE DOS extender
SeeAlso: AH=21h,AH=27h,AH=42h

INT 21 - DOS 1+ - SET INTERRUPT VECTOR
	AH = 25h
	AL = interrupt number
	DS:DX -> new interrupt handler
Notes:	this function is preferred over direct modification of the interrupt
	  vector table
	some DOS extenders place an API on this function, as it is not
	  directly meaningful in protected mode
	under DR DOS 5.0-6.0, this function does not use any of the
	  DOS-internal stacks and may thus be called at any time; however,
	  under Novell DOS 7.0 - DR-DOS 7.02, this function was not reentrant.
	  Since 1998/05/29, DR-DOS 7.03 no longer uses any internal stacks and
	  tests for this function much earlier, to allow a minimal stack usage
	  of just two words in addition to the IRET frame, allowing it to be
	  called from INT 21h functions, specificially device drivers.  This
	  fixes the MCS SMB client
	Novell NetWare (except the new DOS Requester) monitors the offset of
	  any INT 24 set, and if equal to the value at startup, substitutes
	  its own handler to allow handling of network errors; this introduces
	  the potential bug that any program whose INT 24 handler offset
	  happens to be the same as COMMAND.COM's will not have its INT 24
	  handler installed
SeeAlso: AX=2501h,AH=35h

INT 21 P - Phar Lap 386/DOS-Extender - RESET DOS EXTENDER DATA STRUCTURES
	AX = 2501h
	SS = application's original SS or DS (FlashTek X-32VM)
Return: CF clear if successful
	CF set on error
	    caller is operating on X-32 stack (FlashTek X-32VM)
Notes:	Phar Lap uses INT 21/AH=25h as the entry point for all 386/DOS-Extender
	  system calls.	 Only available when directly using 386/DOS-Extender or
	  a compatible DOS extender, or when using a product that was created
	  using 386-DOS/Extender or a compatible
	this function is also supported by FlashTek X-32VM
SeeAlso: AH=30h"Phar Lap"

INT 21 P - Phar Lap 386/DOS-Extender - GET PROTECTED-MODE INTERRUPT VECTOR
	AX = 2502h
	CL = interrupt number
Return: CF clear
	ES:EBX = CS:EIP of protected-mode interrupt handler
Note:	this function is also supported by FlashTek X-32VM
SeeAlso: AX=2503h,AX=2504h,INT 31/AX=0204h

INT 21 P - Phar Lap 386/DOS-Extender - GET REAL-MODE INTERRUPT VECTOR
	AX = 2503h
	CL = interrupt number
Return: CF clear
	EBX = CS:IP of real-mode interrupt handler
Note:	this function is also supported by FlashTek X-32VM
SeeAlso: AX=2502h,AX=2504h,AH=35h,INT 31/AX=0200h

INT 21 P - Phar Lap 386/DOS-Extender - SET PROTECTED-MODE INTERRUPT VECTOR
	AX = 2504h
	CL = interrupt number
	DS:EDX = CS:EIP of protected-mode interrupt handler
Return: CF clear
Note:	this function is also supported by FlashTek X-32VM
SeeAlso: AX=2502h,AX=2505h,INT 31/AX=0205h

INT 21 P - Phar Lap 386/DOS-Extender - SET REAL-MODE INTERRUPT VECTOR
	AX = 2505h
	CL = interrupt number
	EBX = CS:IP of real-mode interrupt handler
Return: CF clear
Note:	this function is also supported by FlashTek X-32VM
SeeAlso: AX=2503h,AX=2504h,INT 31/AX=0201h

INT 21 P - Phar Lap 386/DOS-Extender - SET INT TO ALWAYS GAIN CNTRL IN PR. MODE
	AX = 2506h
	CL = interrupt number
	DS:EDX = CS:EIP of protected-mode interrupt handler
Return: CF clear
Notes:	this function modifies both the real-mode low-memory interrupt
	  vector table and the protected-mode Interrupt Descriptor Table (IDT)
	interrupts occurring in real mode are resignaled in protected mode
	this function is also supported by FlashTek X-32VM

INT 21 P - Phar Lap 386/DOS-Extender - SET REAL- & PROTECTED-MODE INT VECTORS
	AX = 2507h
	CL = interrupt number
	DS:EDX = CS:EIP of protected-mode interrupt handler
	EBX = CS:IP of real-mode interrupt handler
Return: CF clear
Notes:	interrupts are disabled until both vectors have been modified
	this function is also supported by FlashTek X-32VM
SeeAlso: AX=2504h,AX=2505h

INT 21 P - Phar Lap 386/DOS-Extender - GET SEGMENT LINEAR BASE ADDRESS
	AX = 2508h
	BX = segment selector
Return: CF clear if successful
	    ECX = linear base address of segment
	CF set if invalid segment selector
Note:	this function is also supported by FlashTek X-32VM
SeeAlso: AX=2509h

INT 21 P - Phar Lap 386/DOS-Extender - CONVERT LINEAR TO PHYSICAL ADDRESS
	AX = 2509h
	EBX = linear address to convert
Return: CF clear if successful
	    ECX = physical address (carry flag clear)
	CF set if linear address not mapped in page tables
SeeAlso: AX=2508h

INT 21 P - FlashTek X-32VM - GET SYSTEM SEGMENTS AND SELECTORS
	AX = 2509h
Return: CF clear
	EAX high word = default DS
	AX = alias for 16-bit data segment
	BX = real mode code segment
	EDX high word = selector covering full 4GB address space
	DX = default SS
	ESI high word = PSP selector
	SI = environment selector

INT 21 P - Phar Lap 386/DOS-Extender - MAP PHYSICAL MEMORY AT END OF SEGMENT
	AX = 250Ah
	ES = segment selector in the Local Descriptor Table (LDT) of segment
	     to modify
	EBX = physical base address of memory to map (multiple of 4K)
	ECX = number of physical 4K pages to map
Return: CF clear if successful
	    EAX = 32-bit offset in segment of mapped memory
	CF set on error
	    EAX = error code
		08h insufficient memory to create page tables
		09h invalid segment selector
SeeAlso: INT 31/AX=0800h

INT 21 P - Phar Lap 386/DOS-Extender - GET HARDWARE INTERRUPT VECTORS
	AX = 250Ch
Return: CF clear
	AL = base interrupt vector for IRQ0-IRQ7
	AH = base interrupt vector for IRQ8-IRQ15
	BL = interrupt vector for BIOS print screen function (Phar Lap only)
Note:	this function is also supported by FlashTek X-32VM
SeeAlso: INT 31/AX=0400h,INT 67/AX=DE0Ah

INT 21 P - Phar Lap 386/DOS-Extender - GET REAL-MODE LINK INFORMATION
	AX = 250Dh
Return: CF clear
	EAX = CS:IP of real-mode callback procedure (see #01358) that will
		  call through from real mode to a protected-mode routine
	EBX = 32-bit real-mode address of intermode call data buffer
	ECX = size in bytes of intermode call data buffer
	ES:EDX = protected-mode address of intermode call data buffer
Notes:	this function is also supported by FlashTek X-32VM
	X-32VM guarantees the intermode buffer to be at least 4 KB
SeeAlso: AX=250Eh

(Table 01358)
Call Phar Lap real-mode callback with:
	STACK:	DWORD	offset to protected-mode code
		WORD	placeholder for protected-mode CS
		DWORD	pointer to selector structure (see #01359)
			or 0000h:0000h for defaults
		var	parameters for protected-mode procedure
Return: via FAR return

Format of Phar Lap selector structure:
Offset	Size	Description	(Table 01359)
 00h	WORD	protected-mode GS selector
 02h	WORD	protected-mode FS selector
 04h	WORD	protected-mode ES selector
 06h	WORD	protected-mode DS selector

INT 21 P - Phar Lap 386/DOS-Extender - CALL REAL-MODE PROCEDURE
	AX = 250Eh
	EBX = CS:IP of real-mode procedure to call
	ECX = number of two-byte words to copy from protected-mode stack
	      to real-mode stack
Return: CF clear if successful
	    all segment registers unchanged
	    all general registers contain values set by real-mode procedure
	    all other flags set as they were left by real-mode procedure
	    stack unchanged
	CF set on error
	    EAX = error code
		01h not enough real-mode stack space
Note:	this function is also supported by FlashTek X-32VM; under X-32VM, the
	  call will fail if ECX > 0000003Fh
SeeAlso: AX=250Dh,AX=2510h,AH=E1h"OS/286",INT 31/AX=0301h

INT 21 P - Phar Lap 386/DOS-Extender - CONVERT PROTECTED-MODE ADDRESS TO MS-DOS
	AX = 250Fh
	ES:EBX = 48-bit protected-mode address to convert
	ECX = 00000000h or length of data in bytes
Return: CF clear if successful (address < 1MB and contiguous)
	    ECX = 32-bit real-mode MS-DOS address
	CF set on error (address >= 1MB or not contiguous)
	    ECX = linear address
Note:	this function is also supported by FlashTek X-32VM
SeeAlso: AX=2510h

INT 21 P - Phar Lap 386/DOS-Extender - CALL REAL-MODE PROCEDURE, REGISTERS
	AX = 2510h
	EBX = CS:IP of real-mode procedure to call
	ECX = number of two-byte words to copy to protected-mode stack to
	      real-mode stack
	DS:EDX -> pointer to parameter block (see #01360)
Return: CF clear if successful
	    all segment registers unchanged,
	    EDX unchanged
	    all other general registers contain values set by real-mode proc
	    all other flags are set as they were left by real-mode procedure
	    real-mode register values are returned in the parameter block
	CF set on error
	    EAX = error code
		01h not enough real-mode stack space
Note:	unlike most of the preceding 25xxh functions, this one is not
	  supported by FlashTek X-32VM
SeeAlso: AX=250Eh,AX=250Fh

Format of Phar Lap real-mode call parameter block:
Offset	Size	Description	(Table 01360)
 00h	WORD	real-mode DS value
 02h	WORD	real-mode ES value
 04h	WORD	real-mode FS value
 06h	WORD	real-mode GS value
 08h	DWORD	real-mode EAX value
 0Ch	DWORD	real-mode EBX value
 10h	DWORD	real-mode ECX value
 14h	DWORD	real-mode EDX value

INT 21 P - Phar Lap 386/DOS-Extender - ISSUE REAL-MODE INTERRUPT
	AX = 2511h
	DS:EDX -> parameter block (see #01361)
Return: all segment registers unchanged
	EDX unchanged
	all other registers contain values set by the real-mode int handler
	the flags are set as they were left by the real-mode interrupt handler
	real-mode register values are returned in the parameter block
Note:	this function is also supported by FlashTek X-32VM
SeeAlso: AX=2503h,AX=2505h,AX=250Eh,AH=E3h"OS/286",INT 31/AX=0300h

Format of Phar Lap real-mode interrupt parameter block:
Offset	Size	Description	(Table 01361)
 00h	WORD	interrupt number
 02h	WORD	real-mode DS value
 04h	WORD	real-mode ES value
 06h	WORD	real-mode FS value
 08h	WORD	real-mode GS value
 0Ah	DWORD	real-mode EAX value
 0Eh	DWORD	real-mode EDX value
Note: all other real-mode values set from protected-mode registers

INT 21 P - Phar Lap 386/DOS-Extender - LOAD PROGRAM FOR DEBUGGING
	AX = 2512h
	DS:EDX -> pointer to ASCIZ program name
	ES:EBX -> pointer to parameter block (see #01363)
	ECX = size in bytes of LDT buffer
Return: CF clear if successful
	    EAX = number of segment descriptors in LDT
	CF set on error
	    EAX = error code (see #01362)
SeeAlso: AX=2517h

(Table 01362)
Values for Phar Lap error code:
 02h	file not found or path invalid
 05h	access denied
 08h	insufficient memory
 0Ah	environment invalid
 0Bh	invalid file format
 80h	LDT too small

Format of Phar Lap program load parameter block:
Offset	Size	Description	(Table 01363)
Input:
 00h	DWORD	32-bit offset of environment string
 04h	WORD	segment of environment string
 06h	DWORD	32-bit offset of command-tail string
 0Ah	WORD	segment of command-tail string
 0Ch	DWORD	32-bit offset of LDT buffer (size in ECX)
 10h	WORD	segment of LDT buffer
Output:
 12h	WORD	real-mode paragraph address of PSP (see also AH=26h)
 14h	WORD	real/protected mode flag
		0000h  real mode
		0001h  protected mode
 16h	DWORD	initial EIP value
 1Ah	WORD	initial CS value
 1Ch	DWORD	initial ESP value
 20h	WORD	initial SS value
 22h	WORD	initial DS value
 24h	WORD	initial ES value
 26h	WORD	initial FS value
 28h	WORD	initial GS value

INT 21 P - Phar Lap 386/DOS-Extender - ALIAS SEGMENT DESCRIPTOR
	AX = 2513h
	BX = segment selector of descriptor in GDT or LDT
	CL = access-rights byte for alias descriptor
	CH = use-type bit (USE16 or USE32) for alias descriptor
Return: CF clear if successful
	    AX = segment selector for created alias
	CF set on error
	    EAX = error code
		08h insufficient memory (can't grow LDT)
		09h invalid segment selector in BX

INT 21 P - Phar Lap 386/DOS-Extender - CHANGE SEGMENT ATTRIBUTES
	AX = 2514h
	BX = segment selector of descriptor in GDT or LDT
	CL = new access-rights byte
	CH = new use-type bit (USE16 or USE32)
Return: CF clear if successful
	CF set on error
	    EAX = error code
		09h invalid selector in BX
SeeAlso: AX=2515h,INT 31/AX=0009h

INT 21 P - Phar Lap 386/DOS-Extender - GET SEGMENT ATTRIBUTES
	AX = 2515h
	BX = segment selector of descriptor in GDT or LDT
Return: CF clear if successful
	    CL = access-rights byte for segment
	    CH = use-type bit (USE16 or USE32)
	ECX<16-31> destroyed
	CF set on error
	    EAX = error code
		09h invalid segment selector in BX
SeeAlso: AX=2514h

INT 21 P - Phar Lap 386/DOS-Extender v2.2+ - FREE ALL MEMORY OWNED BY LDT
	AX = 2516h
Return: CF clear
Note:	this function must be called from Ring 0 or the CS descriptor is freed

INT 21 P - Phar Lap 386/DOS-Extender v2.1c+ - GET INFO ON DOS DATA BUFFER
	AX = 2517h
Return: CF clear
	ES:EBX -> data buffer (protected mode address)
	ECX -> data buffer (real mode address)
	EDX = size of data buffer in bytes
Note:	the data buffer's address changes after calls to AX=2512h and AX=252Ah
SeeAlso: AX=2512h,AX=252Ah,AX=2530h

INT 21 P - Phar Lap 386/DOS-Extender 2.1c+ - SPECIFY HANDLER FOR MOVED SEGMENTS
	AX = 2518h
	ES:EBX -> function to call when a segment is moved
Return: CF clear
	ES:EBX -> previous handler

INT 21 P - Phar Lap 386/DOS-Extender VMM - GET ADDITIONAL MEMORY ERROR INFO
	AX = 2519h
Return: CF clear
	EAX = error code
	    0000h  no error
	    0001h  out of physical memory
	    0002h  out of swap space (unable to grow swap file)
	    0003h  out of LDT entries and unable to grow LDT
	    0004h  unable to change extended memory allocation mark
	    FFFFFFFFh	paging disabled
Note:	VMM is the Virtual Memory Manager option

INT 21 P - Phar Lap 386/DOS-Extender VMM - LOCK PAGES IN MEMORY
	AX = 251Ah
	EDX = number of 4k pages to lock
	if BL = 00h
	    ECX = linear address of first page to lock
	if BL = 01h
	    ES:ECX -> pointer to first page to lock
Return: CF clear if successful
	CF set on error
	    EAX = error code
		08h insufficient memory
		09h invalid address range
SeeAlso: AX=251Bh,AX=EB06h,INT 31/AX=0600h

INT 21 P - Phar Lap 386/DOS-Extender VMM - UNLOCK PAGES
	AX = 251Bh
	EDX = number of pages to unlock
	if BL = 00h
	    ECX = linear address of first page to unlock
	if BL = 01h
	    ES:ECX -> pointer to first page to unlock
Return: CF clear if successful
	CF set on error
	    EAX = error code
		09h invalid address range
SeeAlso: AX=251Ah,AX=EB07h,INT 31/AX=0601h

INT 21 P - Phar Lap 386/DOS-Extender VMM v2.1c+ - FREE PHYSICAL MEMORY PAGES
	AX = 251Ch
	BH = preservation flag (00h preserve contents, 01h discard contents)
	EDX = number of pages to free
	BL = address type
	    00h linear address
		ECX = linear address of first page to be freed
	    01h pointer
		ES:ECX -> first page to be freed
Return: CF clear if successful
	CF set on error
	    EAX = error code
		08h memory error, swap space full, no VMM or DPMI
		09h invalid address

INT 21 OP - Phar Lap 386/DOS-Extender VMM v2.1c - READ PAGE-TABLE ENTRY
	AX = 251Dh
	BL = address type
	    00h linear address
		ECX = linear address of page table entry to read
	    01h pointer
		ES:ECX -> page table entry to read
Return: CF clear if successful
	    EAX = contents of page table entry
	CF set on error
	    EAX = error code
		09h invalid address or NOPAGE option set
		78h invalid under DPMI
Note:	this function is obsolete; use AX=252Bh/BH=09h instead
SeeAlso: AX=251Eh,AX=252Bh/BH=09h,AX=EB00h,INT 31/AX=0506h

INT 21 OP - Phar Lap 386/DOS-Extender VMM v2.1c - WRITE PAGE-TABLE ENTRY
	AX = 251Eh
	BL = address type
	    00h linear address
		ECX = linear address of page table entry to read
	    01h pointer
		ES:ECX -> page table entry to read
	EDX = new value for page table entry
Return: CF clear if successful
	CF set on error
	    EAX = error code
		09h invalid address or NOPAGE option set
		82h not compatible with DPMI
Note:	this call is obsolete; use AX=252Bh/BH=0Ah instead
SeeAlso: AX=251Dh,AX=252Bh/BH=0Ah,INT 31/AX=0507h

INT 21 P - Phar Lap 386/DOS-Extender VMM - EXHANGE TWO PAGE-TABLE ENTRIES
	AX = 251Fh
	BL = address type
	    00h linear address
		ECX = linear address of first page table entry
		EDX = linear address of second page table entry
	    01h pointer
		ES:ECX -> first page table entry
		ES:EDX -> second page table entry
Return: CF clear if successful
	CF set on error
	    EAX = error code
		09h invalid address or NOPAGE option set
		82h not compatible with DPMI
SeeAlso: AX=251Dh,AX=251Eh

INT 21 P - Phar Lap 386/DOS-Extender VMM - GET MEMORY STATISTICS
	AX = 2520h
	DS:EDX -> pointer to buffer at least 100 bytes in size (see #01364)
	BL = 0 (don't reset VM stats), 1 (reset VM stats)
Return: carry flag clear

Format of Phar Lap VM statistics buffer:
Offset	Size	Description	(Table 01364)
 00h	DWORD	VM status
		0001h VM subsystem is present
		0000h VM not present
 04h	DWORD	"nconvpg" number of conventional memory pages available
 08h	DWORD	"nbimpg" number of Compaq built-in memory pages available
 0Ch	DWORD	"nextpg" total number of extended memory pages
 10h	DWORD	"extlim" extender memory pages limit
 14h	DWORD	"aphyspg" number of physical memory pages allocated to appl
 18h	DWORD	"alockpg" number of locked pages owned by application
 1Ch	DWORD	"sysphyspg" number physical memory pages allocated to system
 20h	DWORD	"nfreepg" number of free physical pages; approx if EMS VCPI
 24h	DWORD	linear address of beginning of application address space
 28h	DWORD	linear address of end of application address space
 2Ch	DWORD	number of seconds since last time VM stats were reset
 30h	DWORD	number of page faults since last time
 34h	DWORD	number of pages written to swap file since last time
 38h	DWORD	number of reclaimed pages (page faults on swapped pages)
 3Ch	DWORD	number of virtual pages allocated to the application
 40h	DWORD	size in pages of swap file
 44h	DWORD	number of system pages allocated with EMS calls
 48h	DWORD	minimum number of conventional memory pages
 4Ch	DWORD	maximum size in pages to which swap file can be increased
 50h	DWORD	"vmflags"
		bit 0 = 1 if page fault in progress
---v4.0+ ---
 54h	DWORD	number of physical pages guaranteed to be free
 58h	DWORD	number of free physical pages currently available
 5Ch	DWORD	size in pages of largest free block of memory (including disk
		  swap space)
 60h	DWORD	reserved

INT 21 P - Phar Lap 386/DOS-Extender VMM - LIMIT PROGRAM'S EXTENDED MEM USAGE
	AX = 2521h
	EBX = max 4k pages of physical extended memory which program may use
Return: CF clear if successful
	   EBX = maximum limit in pages
	   ECX = minimum limit in pages
	CF set on error
	    EAX = error code
		08h insufficient memory or -nopage switch used
SeeAlso: AX=2522h

INT 21 P - Phar Lap 386/DOS-Ext VMM v2.2+ - SPECIFY ALTERNATE PAGE-FAULT HANDLR
	AX = 2522h
	ES:EBX -> alternate handler for page faults
Return: CF clear
	ES:EBX -> previous page-fault handler
SeeAlso: AX=2523h

INT 21 P - Phar Lap 386/DOS-Ext VMM v2.2+ - SPECIFY OUT-OF-SWAP-SPACE HANDLER
	AX = 2523h
	???
Return: ???
Note:	this function takes a DWORD pointer and a DWORD pointer to a DWORD
	  pointer as arguments
SeeAlso: AX=2522h

INT 21 P - Phar Lap 386/DOS-Ext VMM v2.2+ - INSTALL PAGE-REPLACEMENT HANDLERS
	AX = 2524h
	???
Return: ???
Note:	this function takes three DWORD pointers and three DWORD pointers to
	  DWORD pointers as arguments

INT 21 P - Phar Lap 386/DOS-Extender VMM - LIMIT PROGRAM'S CONVENT'L MEM USAGE
	AX = 2525h
	EBX = limit in 4k pages of physical conventional memory which program
	      may use
Return: CF clear if successful
	    EBX = maximum limit in pages
	    ECX = minimum limit in pages
	CF set on error
	    EAX = error code
		08h insufficient memory or -nopage switch used
SeeAlso: AX=2521h

INT 21 P - Phar Lap 386/DOS-Extender - GET CONFIGURATION INFORMATION
	AX = 2526h
	???
Return: ???
Notes:	details are not yet available
	this function takes a pointer to the configuration buffer (see #01365)
	  and a poitner to a BYTE as arguments

Format of Phar Lap configuration buffer:
Offset	Size	Description	(Table 01365)
 00h	DWORD	flags 1 (see #01366)
 04h	DWORD	flags 2 (unused through v5.0)
 08h	DWORD	flags 3 (unused through v5.0)
 0Ch	DWORD	386|DOS-Extender major version
 10h	DWORD	386|DOS-Extender minor version
 14h	DWORD	first letter of text after minor version number in version str
 18h	DWORD	beta flag (00h normal release, 01h beta release)
 1Ch	DWORD	processor (3 = 386, 4 = 486)
 20h	DWORD	coprocessor (4 = none, 6 = 287, 7 = 387/486)
 24h	DWORD	Weitek coprocessor flag (0 = none, 1 = present)
 28h	DWORD	machine type (0 = IBM PC compatible, 1 = NEC 9800 series)
 2Ch	DWORD	machine class
		IBM: bus type (0=ISA, 1=MCA, 2=XT, 3=EISA)
		NEC: 0=normal mode, 1=high-res mode
 30h	DWORD	VCPI flag (0 = none, 1 = present)
 34h	DWORD	-WEITEK/-1167 switch (0 = AUTO, 1 = ON, 2 = OFF)
 38h	DWORD	-MINREAL setting
 3Ch	DWORD	-MAXREAL setting
 40h	DWORD	-MINIBUF setting
 44h	DWORD	-MAXIBUF setting
 48h	DWORD	size in bytes of DOS call data buffer
 4Ch	DWORD	number of interrupt stacks (-NISTACK)
 50h	DWORD	interrupt stack size (-ISTKSIZE)
 54h	DWORD	-REALBREAK setting
 58h	DWORD	-CALLBUFS
 5Ch	DWORD	-HWIVEC
 60h	DWORD	-PRIVEC
 64h	DWORD	-INTMAP
 68h	DWORD	-PRIMAP
 6Ch	DWORD	VCPI: master 8259 interrupt vector base (IRQ0 mapping)
 70h	DWORD	VCPI: slave 8259 interrupt vector base (IRQ8 mapping)
 74h	DWORD	BIOS print screen interrupt vector (0 if NEC)
 78h	DWORD	-EXTLOW setting
 7Ch	DWORD	-EXTHIGH setting
 80h	DWORD	lowest physical extended-memory address allocatable
 84h	DWORD	highest physical extended-memory address allocatable + 1
 88h	DWORD	special memory's physical base address (00000000h if none)
 8Ch	DWORD	special memory size in bytes (00000000h if none)
 90h	DWORD	-MAXVCPIMEM setting
 94h	DWORD	-VSCAN
 98h	DWORD	-SWAPCHK (0 = OFF, 1 = ON, 2 = FORCE, 3 = MAX)
 9Ch	DWORD	-CODESIZE setting
 A0h	DWORD	minimum swap file size (-MINSWFSIZE)
 A4h	DWORD	maximum swap fiel size (-MAXSWFSIZE)
 A8h	DWORD	page replacement policy (0 = LFU, 1 = NUR)
 ACh	DWORD	number of GDT entries (-NGDTENT)
 B0h	DWORD	number of LDT entries (-NLDTENT)
 B4h	DWORD	program's privilege level (0-3)
---386|DOS-Extender v3.0+ ---
 B8h	DWORD	-LOCKSTACK setting
 BCh	DWORD	-MAXEXTMEM
 C0h	DWORD	-MAXXMSMEM
 C4h	DWORD	-MAXPGMMEM
 C8h	DWORD	-DATATHRESHOLD
 CCh	DWORD	virtual memory manager flag (0 = not present, 1 = present)
 D0h	DWORD	Cyrix coprocessor flag (0 = no Cyrix EMC387, 1 = present)
 D4h	DWORD	-CYRIX setting (0 = AUTO, 1 = ON, 2 = OFF)
 D8h	DWORD	DPMI flag (0 = not present, 1 = present)
 DCh	DWORD	DPMI major version
 E0h	DWORD	DPMI minor version
 E4h	DWORD	DPMI capabilities flags (see #01367)
 E8h	DWORD	VCPI major version
 ECh	DWORD	VCPI minor version
 F0h	WORD	VCPI: IRQ0-7 physical base interrupt vector
 F2h	WORD	VCPI: IRQ8-15 physical base interrupt vector
 F4h	DWORD	XMS flag (0 = none, 1 = present)
 F8h	DWORD	XMS major version
 FCh	DWORD	XMS minor version
100h	WORD	application's CS selector
102h	WORD	application's DS selector
104h	WORD	application's PSP selector
106h	WORD	application's environment selector
108h	WORD	selector mapping entire first megabyte
10Ah	WORD	selector mapping text video memory
10Ch	WORD	selector mapping video memory (text for IBM, graphics for NEC)
10Eh	WORD	selector mapping Weitek address space, 0000h if not present
110h	WORD	selector mapping Cyrix EMC387 address space, 0000h if none
112h	WORD	reserved (0)
114h	DWORD	real-mode FAR entry point to call to switch to protected mode
		  with no saved context
118h	DWORD	size of LDT in bytes
---386|DOS-Extender v5.0+ ---
11Ch	DWORD	Windows flag (0 = not present, 1 = Windows present)
120h	DWORD	Windows major version
124h	DWORD	Windows minor version
128h	DWORD	Windows mode (0 = real/standard, 1 = enhanced)
12Ch	DWORD	OS/2 flag (0 = not present, 1 = OS/2 present)
130h	DWORD	OS/2 major version
134h	DWORD	OS/2 minor version
138h 50 DWORDs	reserved (0)

Bitfields for flags 1:
Bit(s)	Description	(Table 01366)
 0	-NOPAGE specified
 1	-A20 specified
 2	-VDISK specified
 3	-XT specified
 4	-AT specified
 5	-MCA specified
 6	-EISA specified
 7	-NORMRES specified (NEC only)
 8	-HIGHRES specified (NEC only)
 9	set if -SWFGROW1ST, clear if -NOSWFGROW1ST
 10	-NOVM specified
 11	-SAVEREGS specified
 12	unused (clear)
 13	-NOVCPI specified
 14	-NOMUL specified
 15	-NOBMCHK specified
 16	-NOSPCLMEM or -NOBIM
 17	-NOPGEXP specified
 18	-SWAPDEFDISK specified
---v3.0+ ---
 19	-SAVEINTS specified
 20	-NOLOAD specified
 21	-PAGELOG specified
 22	-OPENDENY specified
 23	-ERRATA17 specified
---v4.1+ ---
 24	-NESTDPMI specified
 25	-NONESTDPMI specified
 26	-NODPMI specified
 27	-NOPCDWEITEK specified
---v4.2+ ---
 28	-WININT21 specified

Bitfields for DPMI capabilities flags:
Bit(s)	Description	(Table 01367)
 0	paging supported
 1	physical device mapping
 2	conventional memory mapping
 3	exceptions restartable

INT 21 P - Phar Lap 386/DOS-Extender VMM - EN/DISABLE STATE SAVE ON INTERRUPTS
	AX = 2527h
	EBX = new status (00h disabled, 01h enabled)
Return: CF clear
	EBX = previous state save flag
SeeAlso: AX=2528h

INT 21 P - Phar Lap 386/DOS-Extender VMM - READ REGISTERS AFTER CTRL-C INT
	AX = 2528h
	DS:EBX -> buffer for registers (see #01368)
Return: CF clear if successful
	    DS:EBX buffer filled
	CF set on error
	    EAX = error code
		83h interrupt state save not enabled
		84h no active interrupt
SeeAlso: AX=2527h

Format of Phar Lap buffer for registers:
Offset	Size	Description	(Table 01368)
 00h  8 BYTEs	unused
 08h  4	DWORDs	EAX,EBX,ECX,EDX
 18h  4 DWORDs	ESI,EDI,EBP,ESP
 28h  6 WORDs	CS,DS,SS,ES,FS,GS
 34h	DWORD	EIP
 38h	DWORD	EFLAGS

INT 21 P - Phar Lap 386/DOS-Extender - LOAD FLAT MODEL .EXP or .REX FILE
	AX = 2529h
	???
Return: ES:EBX -> parameter block (see #01369)
	???
Note:	details not available at this time
SeeAlso: AX=252Ah

Format of Phar Lap program load parameter block:
Offset	Size	Description	(Table 01369)
 00h	DWORD	initial EIP
 04h	WORD	initial CS
 06h	DWORD	initial ESP
 0Ah	WORD	initial SS
 0Ch  4 WORDs	initial DS, ES, FS, GS
 14h	DWORD	minimum size in bytes of program segment
 18h	DWORD	bytes of additional memory allocated
 1Ch	DWORD	flags
		bit 0: child linked with -UNPRIVILEGED
		---v6.0+ ---
		bit 1: child is PE file instead of .EXP
		bit 2: loaded file is a DLL
		bits 3-31 reserved
---v6.0+ ---
 20h	DWORD	module handles (PE files only)
 24h  7 DWORDs	reserved (0)

INT 21 P - Phar Lap 386/DOS-Extender VMM - NEW LOAD PROGRAM FOR DEBUG
	AX = 252Ah
	DS:EDX -> ASCIZ program name
	ES:EBX -> parameter block (see #01363)
	ECX = size of LDT buffer in bytes
	ESI = bit flags
	    bit 0: allow demand paging rather than loading entire program
	    bit 1: demand page from swap file rather than from .EXP
Return: CF clear if successful
	    EAX = VMM handle or FFFFFFFFh if none
	    ECX = number of descriptors in LDT buffer
	CF set on error
	    EAX = error code
		02h file error
		    EBX = file error code (see #01370)
		    ECX = DOS error code if EBX=1,2,3, or 8
		08h insufficient memory
		    EBX = memory error code (see #01371)
		80h LDT buffer too small
		87h called twice without intervening call to AX=2531h
SeeAlso: AX=2512h,AX=2517h,AX=2529h,AX=2531h

(Table 01370)
Values for Phar Lap file error code:
 01h	DOS open error
 02h	DOS seek error
 03h	DOS read error
 04h	not an .EXP or .REX file
 05h	invalid file format
 06h	-OFFSET is not a multiple of 64K
 07h	-NOPAGE incompatible with -REALBREAK/-OFFSET
 08h	DOS error loading .EXE file

(Table 01371)
Values for Phar Lap memory error code:
 01h	out of physical memory
 02h	out of swap space
 04h	unable to change extended memory allocation
 05h	-MAXPGMMEM exceeded
 06h	insufficient low memory to REALBREAK value
 07h	insufficient low memory for PSP and environment

INT 21 Pu - Phar Lap 386/DOS-Extender - CREATE UNMAPPED PAGES
	AX = 252Bh
	BH = 00h
	???
Return: ???

INT 21 Pu - Phar Lap 386/DOS-Extender - CREATE ALLOCATED PAGES
	AX = 252Bh
	BH = 01h
	???
Return: ???

INT 21 Pu - Phar Lap 386/DOS-Extender - CREATE PHYSICAL DEVICE PAGES
	AX = 252Bh
	BH = 02h
	???
Return: ???

INT 21 Pu - Phar Lap 386/DOS-Extender - MAP DATA FILE
	AX = 252Bh
	BH = 03h
	???
Return: ???
SeeAlso: AX=252Bh/BH=0Bh

INT 21 Pu - Phar Lap 386/DOS-Extender - GET PAGE TYPES
	AX = 252Bh
	BH = 04h
	???
Return: ???
Note:	returns one word per page
SeeAlso: #01372

Bitfields for Phar Lap page information:
Bit(s)	Description	(Table 01372)
 7	mapped to read/write data file
 6	mapped to read-only data file
 5	swapped to disk
 4	locked
 3-0	page type
	0 unmapped
	1 allocated
	2 physical device page

INT 21 P - Phar Lap 386/DOS-Extender - VIRTUAL MEMORY MANAGEMENT - PAGE LOCKING
	AX = 252Bh
	BH = function
	    05h lock pages
	    06h unlock pages
	BL = address type
	    00h linear address
		ECX = linear start address of memory region
	    01h segmented address
		ES:ECX -> start of memory region
	EDX = size of memory region in bytes
Return: CF clear if successful
	CF set on error
Note:	this function is also supported by FlashTek X-32VM; if X-32 is not
	  using virtual memory, this function always succeeds

INT 21 Pu - Phar Lap 386/DOS-Extender - FREE PHYSICAL PAGES
	AX = 252Bh
	BH = function (07h,08h)
	???
Return: ???

INT 21 P - Phar Lap 386/DOS-Extender v4.1 - GET PAGETABLE ENTRY/PAGE TABLE INFO
	AX = 252Bh
	BH = 09h
	BL = subfunction
	    00h get page table entry by linear address
		ECX = linear address for which to get page table entry
	    01h get page table entry by logical address
		ES:ECX = address for which to get page table entry
Return: CF clear if successful
	    EAX = page table entry
	    EBX = additional page table information
	CF set on error
	    EAX = error code
		0009h invalid address
		0082h running under DPMI
SeeAlso: AX=251Dh,AX=252Bh/BH=0Ah

INT 21 P - Phar Lap 386/DOS-Extender v4.1 - SET PAGETABLE ENTRY/PAGE TABLE INFO
	AX = 252Bh
	BH = 0Ah
	BL = subfunction
	    00h set page table entry for linear address
		ECX = linear address for which to get page table entry
	    01h set page table entry for logical address
		ES:ECX = address for which to get page table entry
	ESI = page table entry
	EDI = additional page table information
Return: CF clear if successful
	CF set on error
	    EAX = error code
		0009h invalid address
		0082h running under DPMI
SeeAlso: AX=252Bh/BH=09h

INT 21 P - Phar Lap 386/DOS-Extender v4.1+ - MAP DATA FILE AT FILE OFFSET
	AX = 252Bh
	BH = 0Bh
	BL = subfunction
	    00h by linear address
		ECX = linear address at which to map data file
	    01h by logical address
		ES:ECX = logical address at which to map data file
	EDX = number of bytes to map
	DS:ESI -> mapping structure (see #01373)
	DS:EDI -> ASCIZ filename
Return: CF clear if successful
	CF set on error
	    EAX = error code
		0002h file error
		    ECX = phase (01h opening file, 02h seeking, 03h reading)
		    EDX = error code returned by DOS
		0009h invalid address
		0081h invalid parameters or 386|VMM not present
		0086h all 386|VMM file handles already in use
SeeAlso: AX=252Bh/BH=03h,AX=252Bh/BH=09h

Format of Phar Lap mapping structure:
Offset	Size	Description	(Table 01373)
 00h	DWORD	starting file offset to be mapped
 04h	DWORD	DOS file access and sharing modes (see #01403 at INT 21/AH=3Dh)

INT 21 P - Phar Lap 386/DOS-Ext VMM v3.0 - ADD UNMAPPED PAGES AT END OF SEGMENT
	AX = 252Ch
	BX = segment selector
	ECX = number of 4K pages to add
Return: CF clear if successful
	    EAX = offset in segment of beginning of unmapped pages
	CF set on error
	    EAX = error code
		08h insufficent memory
		09h invalid selector
		82h not supported by current DPMI

INT 21 P - Phar Lap 386/DOS-Extender VMM v2.3+ - CLOSE VMM FILE HANDLE
	AX = 252Dh
	EBX = VMM file handle
Return: CF clear if successful
	CF set on error
	    EAX = error code (81h invalid VMM handle)

INT 21 P - Phar Lap 386/DOS-Extender VMM v2.3+ - GET/SET VMM PARAMETERS
	AX = 252Eh
	CL = direction (00h get parameters, 01h set parameters)
	DS:EBX -> parameter buffer (see #01374)
Return: CF clear if successful
	CF set on error
	    EAX = error code (81h bad parameter value)

Format of Phar Lap VMM parameter buffer:
Offset	Size	Description	(Table 01374)
 00h	DWORD	flags
		bit 0: page fault logging enabled
		---v5.0+ ---
		bit 1: swap extender to disk during DOS EXEC call
		bit 2: don't zero allocated memory
 04h	DWORD	scan period for page aging, in milliseconds
 08h	DWORD	maximum size (in bytes) to check on each page scan
 0Ch 52 BYTEs	unused

INT 21 P - Phar Lap 386/DOS-Ext VMM v3.0 - WRITE RECORD TO VMM PAGE LOG FILE
	AX = 252Fh
	DS:EBX -> data to be written
	CX = size of data in bytes
Return: CF clear if successful
	CF set on error
	    EAX = error code (85h no page log file or not 386/VMM)

INT 21 P - Phar Lap 386/DOS-Ext VMM v2.3+ - SET SIZE OF BUFFER FOR DOS CALLS
	AX = 2530h
	ECX = size of data buffer in bytes (1024 to 65536)
Return: CF clear if successful
	CF set on error
	    EAX = error code
		08h insufficient low memory
		81h invalid size
SeeAlso: AX=2517h

INT 21 P - Phar Lap 386/DOS-Extender VMM v3.0 - READ/WRITE LDT DESCRIPTOR
	AX = 2531h
	BX = segment selector
	ECX = direction (00h read, 01h write)
	DS:EDX -> 8-byte buffer for descriptor contents
Return: CF clear if successful
	CF set on error
	    EAX = error code
		81h invalid selector
		82h DPMI running, or not a code or data segment

INT 21 P - Phar Lap 386/DOS-Extender - GET EXCEPTION HANDLER VECTOR
	AX = 2532h
	CL = exception number (00h-0Fh)
Return: CF clear if successful
	    ES:EBX = CS:EIP of current exception handler
	CF set on error (CL > 0Fh)
Notes:	this call is also supported by the FlashTek X-32VM extender
	this function is incompatible with 386|VMM; use AX=2522h instead
SeeAlso: AX=2522h,AX=2533h

INT 21 P - Phar Lap 386/DOS-Extender - SET EXCEPTION HANDLER VECTOR
	AX = 2533h
	CL = exception number (00h-0Fh)
	DS:EDX = CS:EIP of new exception handler
Return: CF clear if successful
	CF set on error (CL > 0Fh)
Notes:	this call is also supported by the FlashTek X-32VM extender
	this function is incompatible with 386|VMM; use AX=2522h instead
SeeAlso: AX=2522h,AX=2532h

INT 21 P - Phar Lap 386/DOS-Extender v3.0+ - GET INTERRUPT FLAG
	AX = 2534h
Return: CF clear
	EAX = interrupt state (00h disabled, 01h enabled)

INT 21 P - Phar Lap 386/DOS-Extender v3.0+ - READ/WRITE SYSTEM REGISTERS
	AX = 2535h
	EBX = direction (00h read registers, 01h write)
	DS:EDX -> system register record (see #01375)
Return: CF clear
Note:	this call is only available under MS Windows if PHARLAP.386 VDD is
	  installed

Format of Phar Lap system register record:
Offset	Size	Description	(Table 01375)
 00h	DWORD	CR0
 04h  4 DWORDs	DR0,DR1,DR2,DR3
 14h  2 DWORDs	reserved
 1Ch  2 DWORDs	DR6,DR7
 24h  3 DWORDs	reserved

INT 21 P - Phar Lap 386/DOS-Ext VMM v3.0+ - MIN/MAX EXTENDED/CONV MEMORY USAGE
	AX = 2536h
	EBX = bit flags
	    bit 0: modifying conventional memory rather than extended memory
	    bit 1: setting maximum memory usage rather than minimum
	ECX = new limit in 4K pages
Return: CF clear if successful
	    EAX = new limit
	CF set on error
	    EAX = error code (08h memory error or -NOPAGE set)
	    EBX = maximum limit in pages
	    ECX = minimum limit in pages

INT 21 P - Phar Lap 386/DOS-Ext VMM v3.0 - ALLOCATE DOS MEMORY ABOVE DOS BUFFER
	AX = 2537h
	BX = number of paragraphs to allocate
Return: CF clear if successful
	    AX = real-mode segment of allocated block
	CF set on error
	    AX = error code
		07h MS-DOS memory chain corrupted
		08h insufficient low memory
	    BX = size in paragraphs of largest free block
SeeAlso: AH=48h

INT 21 P - Phar Lap 386/DOS-Ext VMM v3.0 - READ PROTMODE REGS AFTER SFTWARE INT
	AX = 2538h
	DS:EBX -> buffer for registers (see #01368)
	ECX = register record to retrieve
	    00h first interrupt state
	    01h next interrupt state
		EDX = handle for current interrupt state
Return: CF clear if successful
	    DS:EBX buffer filled
	    EDX = handle of current interrupt state
	    ESI = number of interrupt which occurred
	CF set on error
	    EAX = error code
		81h invalid handle in EDX
		83h register saving not enabled
		84h no more interrupt states
SeeAlso: AX=2527h,AX=2528h

INT 21 P - Phar Lap 386/DOS-Ext VMM v3.0 - GET OFFSET OF .EXP FILE HEADER
	AX = 2539h
	BX = MS-DOS file handle for open file
Return: CF clear if successful
	    EAX = offset of .EXP header in file
	CF set on error
	    EAX = error code (02h file error)
	    EBX = file error code
		02h DOS error seeking
		03h DOS error reading
		04h invalid file type
		05h invalid file format
	    ECX = DOS error code if EBX=02h or 03h
	current file position in file modified

INT 21 P - Phar Lap 386/DOS-Extender v3.0+ - INSTALL MOD. SEG FAILURE HANDLER
	AX = 253Ah
	ES:EBX -> function to be called when INT 21/AH=4Ah is about to return
		an error
Return: CF clear
	ES:EBX -> previous handler
SeeAlso: AH=4Ah

INT 21 P - Phar Lap 386/DOS-Extender v3.0+ - JUMP TO REAL MODE CODE, NO CONTEXT
	AX = 253Bh
	DS:EBX -> buffer containing register contents (see #01368)
Return: never returns
SeeAlso: AX=2528h

INT 21 P - Phar Lap 386/DOS-Extender VMM v3.0+ - SHRINK 386|VMM SWAP FILE
	AX = 253Ch
Return: CF clear
	EAX = old size of swap file in bytes
	EBX = new size of swap file in bytes

INT 21 P - Phar Lap 386/DOS-Extender v4.0+ - READ/WRITE IDT DESCRIPTOR
	AX = 253Dh
	BL = interrupt number
	ECX = direction (0 = read, 1 = write)
	DS:EDX -> 8-byte buffer for descriptor
Return: CF clear if successful
	    DS:EDX filled if reading
	CF set on error
	    EAX = error code (0082h if running under DPMI)
Desc:	access hardware-level IDT rather than the internal 386/DOS-Extender
	  shadow IDT
Notes:	this call will always fail under DPMI because it is not possible to
	  access the IDT
	the descriptor is not checked when writing
	this call can normally be used only by programs running in ring 0
	  because the processor does not allow an interrupt to be vectored to
	  a less privileged ring

INT 21 Pu - Phar Lap 386/DOS-Extender v6.0+ - ALLOCATE LDT DESCRIPTOR
	AX = 253Fh
	BX = LDT descriptor to allocate (0000h for any)
	???
Return: ???

INT 21 Pu - Phar Lap 386/DOS-Extender v6.0+ - FORCE ALIAS OF SEGMENT
	AX = 2540h
	???
Return: ???

INT 21 Pu - Phar Lap 386/DOS-Extender v6.0+ - FREE DLL
	AX = 2544h
	???
Return: ???

INT 21 Pu - Phar Lap 386/DOS-Extender v6.0+ - GET/SET PROCEDURE ADDRESS
	AX = 2545h
	ECX = direction (00h get, 01h set)
	???
Return: ???

INT 21 Pu - Phar Lap 386/DOS-Extender v6.0+ - GET MODULE HANDLE
	AX = 2546h
	???
Return: ???

INT 21 P - Phar Lap 386/DOS-Extender - ALLOCATE MS-DOS MEMORY BLOCK
	AX = 25C0h
	BX = number of 16-byte paragraphs of MS-DOS memory requested
Return: CF clear if successful
	    AX = real-mode paragraph address of memory
	CF set on error
	    AX = error code
		07h MS-DOS memory control blocks destroyed
		08h insufficient memory
	    BX = size in paragraphs of largest available memory block
SeeAlso: AX=25C1h,AX=25C2h

INT 21 P - Phar Lap 386/DOS-Extender - RELEASE MS-DOS MEMORY BLOCK
	AX = 25C1h
	CX = real-mode paragraph address of memory block to free
Return: CF clear if successful
	    EAX destroyed
	CF set on error
	    AX = error code
		07h MS-DOS memory control blocks destroyed
		09h invalid memory block address in CX
SeeAlso: AX=25C0h,AX=25C2h

INT 21 P - Phar Lap 386/DOS-Extender - MODIFY MS-DOS MEMORY BLOCK
	AX = 25C2h
	BX = new requested block size in paragraphs
	CX = real-mode paragraph address of memory block to modify
Return: CF clear if successful
	    EAX destroyed
	CF set on error
	    AX = error code
		07h MS-DOS memory control blocks destroyed
		08h insufficient memory
		09h invalid memory block address in CX
	    BX = size in paragraphs of largest available memory block
SeeAlso: AX=25C0h,AX=25C1h

INT 21 P - Phar Lap 386/DOS-Extender - EXECUTE PROGRAM
	AX = 25C3h
	ES:EBX -> pointer to parameter block (see #01377)
	DS:EDX -> pointer to ASCIZ program filename
Return: CF clear if successful
	    all registers unchanged
	CF set on error
	    EAX = error code (see #01376)

(Table 01376)
Values for Phar Lap error code:
 01h	function code in AL is invalid ???
 02h	file not found or path invalid
 05h	access denied
 08h	insufficient memory to load program
 0Ah	environment invalid
 0Bh	invalid file format

Format of parameter block:
Offset	Size	Description	(Table 01377)
 00h	DWORD	32-bit offset of environment string
 04h	WORD	segment selector of environment string
 06h	DWORD	32-bit offset of command-tail string
 0Ah	WORD	segment selector of command-tail string

INT 21 - DOS 1+ - CREATE NEW PROGRAM SEGMENT PREFIX
	AH = 26h
	DX = segment at which to create PSP (see #01378)
Return: AL destroyed
Notes:	new PSP is updated with memory size information; INTs 22h, 23h, 24h
	  taken from interrupt vector table; the parent PSP field is set to 0
	(DOS 2+) DOS assumes that the caller's CS is the segment of the PSP to
	  copy
BUG:	DR DOS 6.0 original releases 05/1991 & 08/1991 had a problem where the
	  segment from which the PSP was copied was incorrect so that the PSP
	  was not filled correctly and did not contain the command tail.  The
	  DR DOS 6.0 BDOS patch "PAT312" English (1992/01/07, XDIR /C: A0C6h)
	  and later "full" rebuilds fix this problem (see INT 21/AX=4452h).
SeeAlso: AH=4Bh,AH=50h,AH=51h,AH=55h,AH=62h,AH=67h

Format of Program Segment Prefix (PSP):
Offset	Size	Description	(Table 01378)
 00h  2 BYTEs	INT 20 instruction for CP/M CALL 0 program termination
		the CDh 20h here is often used as a signature for a valid PSP
 02h	WORD	segment of first byte beyond memory allocated to program
 04h	BYTE	(DOS) unused filler
		(OS/2) count of fake DOS version returns
 05h	BYTE	CP/M CALL 5 service request (FAR CALL to absolute 000C0h)
		BUG: (DOS 2+ DEBUG) PSPs created by DEBUG point at 000BEh
 06h	WORD	CP/M compatibility--size of first segment for .COM files
 08h  2 BYTEs	remainder of FAR JMP at 05h
 0Ah	DWORD	stored INT 22 termination address
 0Eh	DWORD	stored INT 23 control-Break handler address
 12h	DWORD	DOS 1.1+ stored INT 24 critical error handler address
 16h	WORD	segment of parent PSP
 18h 20 BYTEs	DOS 2+ Job File Table, one byte per file handle, FFh = closed
 2Ch	WORD	DOS 2+ segment of environment for process (see #01379)
 2Eh	DWORD	DOS 2+ process's SS:SP on entry to last INT 21 call
 32h	WORD	DOS 3+ number of entries in JFT (default 20)
 34h	DWORD	DOS 3+ pointer to JFT (default PSP:0018h)
 38h	DWORD	DOS 3+ pointer to previous PSP (default FFFFFFFFh in 3.x)
		used by SHARE in DOS 3.3
 3Ch	BYTE	DOS 4+ (DBCS) interim console flag (see AX=6301h)
		Novell DOS 7 DBCS interim flag as set with AX=6301h
		(possibly also used by Far East MS-DOS 3.2-3.3)
 3Dh	BYTE	(APPEND) TrueName flag (see INT 2F/AX=B711h)
 3Eh	BYTE	(Novell NetWare) flag: next byte initialized if CEh
		(OS/2) capabilities flag
 3Fh	BYTE	(Novell NetWare) Novell task number if previous byte is CEh
 40h  2 BYTEs	DOS 5+ version to return on INT 21/AH=30h
 42h	WORD	(MSWindows3) selector of next PSP (PDB) in linked list
		Windows keeps a linked list of Windows programs only
 44h	WORD	(MSWindows3) "PDB_Partition"
 46h	WORD	(MSWindows3) "PDB_NextPDB"
 48h	BYTE	(MSWindows3) bit 0 set if non-Windows application (WINOLDAP)
 49h	BYTE	unused by DOS versions <= 6.00
 4Ch	WORD	(MSWindows3) "PDB_EntryStack"
 4Eh  2 BYTEs	unused by DOS versions <= 6.00
 50h  3 BYTEs	DOS 2+ service request (INT 21/RETF instructions)
 53h  2 BYTEs	unused in DOS versions <= 6.00
 55h  7 BYTEs	unused in DOS versions <= 6.00; can be used to make first FCB
		  into an extended FCB
 5Ch 16 BYTEs	first default FCB, filled in from first commandline argument
		overwrites second FCB if opened
 6Ch 16 BYTEs	second default FCB, filled in from second commandline argument
		  overwrites beginning of commandline if opened
 7Ch  4 BYTEs	unused
 80h 128 BYTEs	commandline / default DTA
		command tail is BYTE for length of tail, N BYTEs for the tail,
		  followed by a BYTE containing 0Dh
Notes:	in DOS v3+, the limit on simultaneously open files may be increased by
	  allocating memory for a new open file table, filling it with FFh,
	  copying the first 20 bytes from the default table, and adjusting the
	  pointer and count at 34h and 32h.  However, DOS will only copy the
	  first 20 file handles into a child PSP (including the one created on
	  EXEC).
	in an OS/2 DOS box, values of D0h-FEh in the open file table indicate
	  device drivers
	network redirectors based on the original MS-Net implementation use
	  values of 80h-FEh in the open file table to indicate remote files;
	  Novell NetWare also uses values from FEh down to 80h or one more than
	  FILES= (whichever is greater) to indicate remote files (except on
	  OS/2, where is uses CFh down to 80h)
	MS-DOS 5.00 incorrectly fills the FCB fields when loading a program
	  high; the first FCB is empty and the second contains the first
	  parameter
	some DOS extenders place protected-mode values in various PSP fields
	  such as the "parent" field, which can confuse PSP walkers.  Always
	  check either for the CDh 20h signature or that the suspected PSP is
	  at the beginning of a memory block which owns itself (the preceding
	  paragraph should be a valid MCB with "owner" the same as the
	  suspected PSP).
	Novell NetWare updates the fields at offsets 3Eh and 3Fh without
	  checking that a legal PSP segment is current; see AH=50h for further
	  discussion
	for 4DOS and Windows95, the command tail may be more than 126
	  characters; in that case, the length byte will be set to 7Fh (with
	  an 0Dh in the	 127th position at offset FFh), and the first 126
	  characters will be stored in the PSP, with the entire command line
	  in the environment variable CMDLINE; under at least some versions
	  of 4DOS, the byte at offset FFh is *not* set to 0Dh, so there is no
	  terminating carriage return in the PSP's command tail.
BUG:	When shelling out from the Borland Pascal 7.00 IDE, overly-long
	  command lines will not be delimited by a 0Dh character, and the
	  length byte is set to 80h!  A workaround is to always patch in a
	  0Dh at the last position of the command line buffer before scanning
	  the command line.

Format of environment block:
Offset	Size	Description	(Table 01379)
 00h  N BYTEs	first environment variable, ASCIZ string of form "var=value"
      N BYTEs	second environment variable, ASCIZ string
	...
      N BYTEs	last environment variable, ASCIZ string of form "var=value"
	BYTE	00h
---DOS 3.0+ ---
	WORD	number of strings following environment (normally 1)
      N BYTEs	ASCIZ full pathname of program owning this environment
		other strings may follow

INT 21 - DOS 1+ - RANDOM BLOCK READ FROM FCB FILE
	AH = 27h
	CX = number of records to read
	DS:DX -> opened FCB (see #01345)
Return: AL = status
	    00h successful, all records read
	    01h end of file, no data read
	    02h segment wrap in DTA, no data read
	    03h end of file, partial read
	Disk Transfer Area filled with records read from file
	CX = number of records read (return AL = 00h or 03h)
Notes:	read begins at current file position as specified in FCB; the file
	  position is updated after reading
	not supported by MS Windows 3.0 DOSX.EXE DOS extender
SeeAlso: AH=21h,AH=28h,AH=3Fh"DOS"

INT 21 - DOS 1+ - RANDOM BLOCK WRITE TO FCB FILE
	AH = 28h
	CX = number of records to write
	DS:DX -> opened FCB (see #01345)
	Disk Transfer Area contains records to be written
Return: AL = status
	    00h successful
	    01h disk full or file read-only
	    02h segment wrap in DTA
	CX = number of records written
Notes:	write begins at current file position as specified in FCB; the file
	  position is updated after writing
	if CX = 0000h on entry, no data is written; instead the file size is
	  adjusted to be the same as the file position specified by the random
	  record and record size fields of the FCB
	if the data to be written is less than a disk sector, it is copied into
	  a DOS disk buffer, to be written out to disk at a later time
	not supported by MS Windows 3.0 DOSX.EXE DOS extender
SeeAlso: AH=22h,AH=27h,AH=40h,AH=59h/BX=0000h

INT 21 - DOS 1+ - PARSE FILENAME INTO FCB
	AH = 29h
	AL = parsing options (see #01380)
	DS:SI -> filename string (both '*' and '?' wildcards OK)
	ES:DI -> buffer for unopened FCB
Return: AL = result code
	    00h successful parse, no wildcards encountered
	    01h successful parse, wildcards present
	    FFh failed (invalid drive specifier)
	DS:SI -> first unparsed character
	ES:DI buffer filled with unopened FCB (see #01345)
Notes:	asterisks in the name are expanded to question marks in the FCB
	all processing stops when a filename terminator is encountered
	cannot be used with filespecs which include a path (DOS 2+)
	Novell NetWare monitors the result code since an 'invalid drive' may
	  signal an attempt to reconnect a network drive; if there are no
	  connections to the specified drive, NetWare attempts to build a
	  connection and map the drive to the SYS:LOGIN directory
SeeAlso: AH=0Fh,AH=16h,AH=26h

Bitfields for parsing options:
Bit(s)	Description	(Table 01380)
 0	skip leading separators
 1	use existing drive number in FCB if no drive is specified, instead of
	  setting field to zero
 2	use existing filename in FCB if no base name is specified, instead of
	  filling field with blanks
 3	use existing extension in FCB if no extension is specified, instead of
	  filling field with blanks
 4-7	reserved (0)

INT 21 - DOS 1+ - GET SYSTEM DATE
	AH = 2Ah
Return: CX = year (1980-2099)
	DH = month
	DL = day
---DOS 1.10+---
	AL = day of week (00h=Sunday)
SeeAlso: AH=2Bh"DOS",AH=2Ch,AH=E7h"Novell",INT 1A/AH=04h,INT 2F/AX=120Dh

INT 21 - DOS 1+ - SET SYSTEM DATE
	AH = 2Bh
	CX = year (1980-2099)
	DH = month (1-12)
	DL = day (1-31)
Return: AL = status
	    00h successful
	    FFh invalid date, system date unchanged
Note:	DOS 3.3+ also sets CMOS clock; due to the limitations of the CLOCK$
	  driver interface, the CMOS time is also updated to the current
	  DOS time (which is the BIOS time-of-day clock with the default
	  CLOCK$ driver)
SeeAlso: AH=2Ah,AH=2Dh,INT 1A/AH=05h

INT 21 - AI Architects - ??? - INSTALLATION CHECK
	AH = 2Bh
	CX = 4149h ('AI')
	DX = 413Fh ('A?')
Return: AL <> FFh if installed
Note:	Borland's TKERNEL makes this call

INT 21 - Super PC-Kwik v3.20+ - INSTALLATION CHECK
	AH = 2Bh
	CX = 4358h ('CX')
Return: AL = FFh if PC-Kwik/PC-Cache not installed
	AL = 00h if installed
	    CF clear
	    CX = 6378h ('cx')
	    BX = ???
	    DX = version (DH = major version, DL = binary minor version)
Note:	PC Tools PC-Cache v5.x and Qualitas Qcache v4.00 are OEM versions of
	  Super PC-Kwik, and thus support this call (PC-Cache 5.1 corresponds
	  to PC-Kwik v3.20)
SeeAlso: INT 13/AH=A0h,INT 13/AH=B0h,INT 16/AX=FFA5h/CX=1111h
Index:	PC-Cache;installation check|Qualitas Qcache;installation check
Index:	installation check;PC-Cache 5.x|installation check;Qualitas Qcache

INT 21 - DESQview - INSTALLATION CHECK
	AH = 2Bh
	CX = 4445h ('DE')
	DX = 5351h ('SQ')
	AL = subfunction (DV v2.00+)
	    01h get version
		Return: BX = version (BH = major, BL = minor)
		Note: early copies of v2.00 return 0002h
	    02h get shadow buffer info, and start shadowing
		Return: BH = rows in shadow buffer
			BL = columns in shadow buffer
			DX = segment of shadow buffer
	    04h get shadow buffer info
		Return: BH = rows in shadow buffer
			BL = columns in shadow buffer
			DX = segment of shadow buffer
	    05h stop shadowing
Return: AL = FFh if DESQview not installed
Notes:	in DESQview v1.x, there were no subfunctions; this call only identified
	  whether or not DESQview was loaded.  DESQview v2.52 performs function
	  01h for all subfunction requests 0Ch and higher and appears to ignore
	  all lower-numbered functions not listed here.
	DESQview versions 2.50-2.52 are part of DESQview/X v1.0x; version 2.53
	  is part of DESQview/X v1.10; and version 2.63 is part of DESQview/X
	  v2.00.
BUG:	subfunction 05h does not appear to work correctly in DESQview 2.52
SeeAlso: INT 10/AH=FEh,INT 10/AH=FFh,INT 15/AX=1024h,INT 15/AX=DE30h

INT 21 - ELRES v1.1 - INSTALLATION CHECK
	AH = 2Bh
	CX = 454Ch ('EL')
	DX = 5253h ('RS')
Return: ES:BX -> ELRES history structure (see #01381)
	DX = DABEh (signature, DAve BEnnett)
Program: ELRES is an MS-DOS return code (errorlevel) recorder by David H.
	  Bennett which stores recent errorlevel values, allows them to be
	  retrieved for use in batch files, and can place them in an
	  environment variable
SeeAlso: AH=4Bh"ELRES",AH=4Dh

Format of ELRES history structure:
Offset	Size	Description	(Table 01381)
 00h	WORD	number of return codes which can be stored by following buffer
 02h	WORD	current position in buffer (treated as a ring)
 04h  N BYTEs	ELRES buffer

INT 21 - The Volkov Commander - GET POINTER TO LEFT PANEL DATA STRUCTURE
	AX = 2B00h
	CX = 5643h ('VC')
	DX = 4F4Dh ('OM')
Return: AL = 0
	ES:BX -> left panel data structure
Program: Volcov Commander is a shell for MS-DOS by Vsevolod V. Volkov
SeeAlso: AX=2B01h/CX=5643h,AX=2B02h/CX=5643h

INT 21 - The Volkov Commander - GET POINTER TO RIGHT PANEL DATA STRUCTURE
	AX = 2B01h
	CX = 5643h ('VC')
	DX = 4F4Dh ('OM')
Return: AL = 0
	ES:BX -> right panel data structure
SeeAlso: AX=2B00h/CX=5643h,AX=2B02h/CX=5643h

INT 21 - The Volkov Commander - GET POINTER TO GLOBAL VARIABLES
	AX = 2B02h
	CX = 5643h ('VC')
	DX = 4F4Dh ('OM')
Return: AL = 0
	ES:BX -> global variables
SeeAlso: AX=2B00h/CX=5643h,AX=2B01h/CX=5643h

INT 21 - Quarterdeck DOS-UP.SYS v2.00 - INSTALLATION CHECK
	AX = 2B01h
	CX = 444Dh ('DM')
	DX = 4158h ('AX')
Return: AX = 0000h if installed
	    BX = DOS-UP version (BH = minor, BL = major)
	    CX = 4845h ('HE')
	    DX = 5245h ('RE')
	    ES = DOS-UP driver segment

INT 21 - TAME v2.10+ - INSTALLATION CHECK
	AX = 2B01h
	CX = 5441h ('TA')
	DX = 4D45h ('ME')
---v2.60---
	BH = ???
	    00h skip ???, else do
Return: AL = 02h if installed
	ES:DX -> data area in TAME-RES (see #01382,#01386,#01388)
Program: TAME is a shareware program by David G. Thomas which gives up CPU
	  time to other partitions under a multitasker when the current
	  partition's program incessantly polls the keyboard or system time

Format of TAME 2.10-2.20 data area:
Offset	Size	Description	(Table 01382)
 00h	BYTE	data structure minor version number (01h in TAME 2.20)
 01h	BYTE	data structure major version number (07h in TAME 2.20)
 02h	DWORD	number of task switches
 06h	DWORD	number of keyboard polls
 0Ah	DWORD	number of time polls
 0Eh	DWORD	number of times DESQview told program runs only in foreground
 12h	DWORD	original INT 10h
 16h	DWORD	original INT 14h
 1Ah	DWORD	original INT 15h
 1Eh	DWORD	original INT 16h
 22h	DWORD	original INT 17h
 26h	DWORD	original INT 21h
 2Ah	DWORD	original INT 28h
 2Eh	WORD	offset of TAME INT 10h handler
 30h	WORD	offset of TAME INT 14h handler
 32h	WORD	offset of TAME INT 15h handler
 34h	WORD	offset of TAME INT 16h handler
 36h	WORD	offset of TAME INT 17h handler
 38h	WORD	offset of TAME INT 21h handler
 3Ah	WORD	offset of TAME INT 28h handler
 3Ch	WORD	X in /max:X,Y or /freq:X,Y
 3Eh	WORD	Y in /max:X,Y or /freq:X,Y
 40h	WORD	number of polls remaining before next task switch
 42h	WORD	/KEYIDLE value
 44h	BYTE	interrupts already grabbed by TAME (see #01383)
 45h	BYTE	flags for interrupts which may be acted on (same bits as above)
 46h	BYTE	TAME enabled (01h) or disabled (00h)
 47h	BYTE	/TIMEPOLL (01h) or /NOTIMEPOLL (00h)
 48h	BYTE	/NOTIMER (01h) or /TIMER (00h)
 49h	BYTE	window or task number for this task
 4Ah	BYTE	multitasker type (see #01384)
 4Bh	BYTE	type of task switching selected
		bit 0: DESQview???
		bit 1: DoubleDOS???
		bit 2: TopView???
		bit 3: KeySwitch
		bit 4: HLT instruction
 4Ch	BYTE	???
 4Dh	BYTE	flags
		bit 1: /FREQ instead of /MAX
 4Eh	BYTE	/FG: value
 4Fh	BYTE	task switches left until next FGONLY DESQview API call
 50h	BYTE	???

Bitfields for interrupts already grabbed by TAME:
Bit(s)	Description	(Table 01383)
 0	INT 10h
 1	INT 14h
 2	INT 15h
 3	INT 16h
 4	INT 17h
 5	INT 21h
 6	INT 28h

(Table 01384)
Values for multitasker type:
 01h	DESQview
 02h	DoubleDOS
 03h	TopView
 04h	OmniView
 05h	VM/386

Bitfields for type of task switching selected:
Bit(s)	Description	(Table 01385)
 0	DESQview
 1	DoubleDOS
 2	TopView
 3	OmniView
 4	KeySwitch
 5	HLT instruction

Format of TAME 2.30 data area:
Offset	Size	Description	(Table 01386)
 00h	BYTE	data structure minor version number (02h in TAME 2.30)
 01h	BYTE	data structure major version number (0Ah in TAME 2.30)
 02h	DWORD	number of task switches
 06h	DWORD	number of keyboard polls
 0Ah	DWORD	number of time polls
 0Eh	DWORD	number of times DESQview told program runs only in foreground
 12h	DWORD	time of last /CLEAR or TAME-RES load
 16h	DWORD	time yielded
 1Ah	DWORD	time spent polling
 1Eh	DWORD	time spent waiting on key input with INT 16/AH=01h,11h
 22h	DWORD	original INT 10h
 26h	DWORD	original INT 14h
 2Ah	DWORD	original INT 15h
 2Eh	DWORD	original INT 16h
 32h	DWORD	original INT 17h
 36h	DWORD	original INT 21h
 3Ah	DWORD	original INT 28h
 3Eh	WORD	offset of TAME INT 10h handler
 40h	WORD	offset of TAME INT 14h handler
 42h	WORD	offset of TAME INT 15h handler
 44h	WORD	offset of TAME INT 16h handler
 46h	WORD	offset of TAME INT 17h handler
 48h	WORD	offset of TAME INT 21h handler
 4Ah	WORD	offset of TAME INT 28h handler
 4Ch	WORD	X in /max:X,Y or /freq:X,Y
 4Eh	WORD	Y in /max:X,Y or /freq:X,Y
 50h	WORD	number of polls remaining before next task switch
 52h	WORD	/KEYIDLE value
 54h	WORD	/FG: value
 56h	WORD	task switches left until next FGONLY DESQview API call
 58h	WORD	multitasker version
 5Ah	WORD	virtual screen segment
 5Ch	BYTE	interrupts already grabbed by TAME (see #01383)
 5Dh	BYTE	flags for interrupts which may be acted on (same bits as above)
 5Eh	BYTE	window or task number for this task
 5Fh	BYTE	multitasker type (see #01384)
 60h	BYTE	type of task switching selected (bit flags) (see #01385)
 61h	BYTE	watch_DOS
 62h	BYTE	action flags (see #01387)
 63h	BYTE	old status
 64h	WORD	signature DA34h

Bitfields for TAME action flags:
Bit(s)	Description	(Table 01387)
 0	TAME enabled
 1	/FREQ instead of /MAX (X and Y count fields are per tick)
 2	/TIMEPOLL
 3	/KEYPOLL
 4	inhibit timer
 5	enable status monitoring
SeeAlso: #01386,#01388

Format of TAME 2.60 data area:
Offset	Size	Description	(Table 01388)
 00h	BYTE	data structure minor version number (02h in TAME 2.60)
 01h	BYTE	data structure major version number (0Bh in TAME 2.60)
 02h	DWORD	number of task switches
 06h	DWORD	number of keyboard polls
 0Ah	DWORD	number of time polls
 0Eh	DWORD	number of times DESQview told program runs only in foreground
 12h	DWORD	time of last /CLEAR or TAME-RES load
 16h	DWORD	time yielded
 1Ah	DWORD	time spent polling
 1Eh	DWORD	time spent waiting on key input with INT 16/AH=01h,11h
 22h  4 BYTEs	???
 26h	DWORD	original INT 10h
 2Ah	DWORD	original INT 14h
 2Eh	DWORD	original INT 15h
 32h	DWORD	original INT 16h
 36h	DWORD	original INT 17h
 3Ah	DWORD	original INT 21h
 3Eh	DWORD	original INT 28h
 42h	WORD	offset of TAME INT 10h handler
 44h	WORD	offset of TAME INT 14h handler
 46h	WORD	offset of TAME INT 15h handler
 48h	WORD	offset of TAME INT 16h handler
 4Ah	WORD	offset of TAME INT 17h handler
 4Ch	WORD	offset of TAME INT 21h handler
 4Eh	WORD	offset of TAME INT 28h handler
 50h	WORD	X in /max:X,Y or /freq:X,Y
 52h	WORD	Y in /max:X,Y or /freq:X,Y
 54h	WORD	number of polls remaining before next task switch
 56h	WORD	/KEYIDLE value
 58h  4 BYTEs	???
 5Ch	WORD	X in /boost:X,Y
 5Eh	WORD	Y in /boost:X,Y
 60h	WORD	/FG: value
 62h	WORD	task switches remaining until next FGONLY DESQview API call
 64h	WORD	multitasker version ???
 66h	WORD	virtual screen segment
 68h	BYTE	interrupts already grabbed by TAME (see #01383)
 69h	BYTE	flags for interrupts which may be acted on (same bits as above)
 6Ah	BYTE	window or task number for this task
 6Bh	BYTE	multitasker type (see #01384)
 6Ch	BYTE	type of task switching selected (bit flags) (see #01385)
 6Dh	BYTE	watch_DOS
 6Eh	BYTE	action flags (see #01387)
 6Fh	BYTE	old status
 70h	WORD	signature DA34h

INT 21 - VIRUS - "Maltese Amoeba" - INSTALLATION CHECK
	AX = 2B16h
	CX = 0643h
Return: AX = 1603h if installed

INT 21 - pcANYWHERE IV/LAN - INSTALLATION CHECK
	AX = 2B44h ('D')
	BX = 4D41h ('MA')
	CX = 7063h ('pc')
	DX = 4157h ('AW')
Return: AX = resident program
	    4F4Bh ('OK') if large host resident
	    6F6Bh ('ok') if small host resident
	CX:DX -> API entry point (see #01389)
SeeAlso: INT 16/AH=79h

(Table 01389)
Call pcANYWHERE API entry point with:
	AX = 0000h get pcANYWHERE IV version
	    DS:SI -> BYTE buffer for host type code
	    Return: AH = version number
		    AL = revision number
		    DS:DI buffer byte filled with
			00h full-featured host
			01h limited-feature LAN host
			other API may not be supported
	AX = 0001h initialize operation
	    DS:SI -> initialization request structure (see #01390)
	    Return: AX = function status (see #01393)
	AX = 0002h get status
	    Return: AH = current operating mode (see #01390)
		    AL = current connection status (see #01392)
	AX = 0003h suspend remote screen updates
	    Return: AX = function status (see #01393)
	AX = 0004h resume screen updates
	    Return: AX = function status (see #01393)
	AX = 0005h end current remote access session
	    DS:SI -> termination request structure (see #01391)
	    Return: AX = function status (see #01393)
	AX = 0006h remove pcANYWHERE IV from memory
	    Return: AX = status (see #01393)
	AX = 8000h read data from communications channel
	    DS:BX -> buffer
	    CX = buffer size
	    Return: AX >= number of characters read/available
		    AX < 0 on error
	AX = 8001h write data to communications channel
	    DS:BX -> buffer
	    CX = buffer size
	    Return: AX >= number of characters written
		    AX < 0 on error
	AX = 8002h get connection status
	    Return: AX = status
			> 0000h if connection active
			= 0000h if connection lost
			< 0000h on error

Format of pcANYWHERE initialization request structure:
Offset	Size	Description	(Table 01390)
 00h	BYTE	operating mode
		00h wait for a call
		01h hot key activates
		02h incoming call activates
		03h initiate a call
 01h  3 BYTEs	user ID to append to config file names
 04h	WORD	DS-relative pointer to path for config files
 06h	WORD	DS-relative pointer to path for program files

Format of pcANYWHERE termination request structure:
Offset	Size	Description	(Table 01391)
 00h	BYTE	operating mode after termination
		00h wait for a call
		01h hot key activates
		02h incoming call activates
		80h use current mode
		FFh remove from memory

Bitfields for current connection status:
Bit(s)	Description	(Table 01392)
 0	a physical connection is active
 1	remove screen updating is active
 2	connection checking is active
 3	hot key detection is active
 4	background file transfer is active

(Table 01393)
Values for pcANYWHERE function status:
 0000h	function completed successfully
 FFD1h	unable to release interrupt vectors
 FFD2h	unable to release allocated memory
 FFF2h	unable to establish a connection when operating mode is
	  "Initiate a call"
 FFF3h	modem configuration is invalid (corrupt config)
 FFF4h	modem initialization failed (no modem response)
 FFF5h	the communications device could not be initialized
 FFF6h	the host operator aborted the function
 FFF7h	the communications driver type specified in the configuration file is
	  different than the one loaded when pcANYWHERE IV was started
 FFF9h	the configuration file is invalid
 FFFAh	the configuration file could not be found
 FFFBh	no session is active
 FFFCh	a remote access session is active
 FFFDh	the specified operating mode is invalid

INT 21 - Volkov Commander - INSTALLATION CHECK
	AH = 2Bh
	CX = 5643h ('VC')
	DX = 4F4Dh ('OM')
	AL = function number
	    00h get left window data address
	    01h get right window data address
	    02h get address of general variables
Return: AL = 00h if Volkov Commander installed
	    AH = version code (27h for v4.00.039)
	    ES:BX -> requested data
Program: Volkov Commander is a Norton Commander-like DOS shell

INT 21 - WDTSR.COM - INSTALLATION CHECK
	AH = 2Bh
	CX = 6269h ('bi')
	DX = 742Dh ('t-')
Return: AL = FFh if not installed
	AL = 77h ('w') if WDTSR is installed
	    CX = 6174h ('at')
	    DX = 6368h ('ch')
	    ES = resident code segment
	    ES:DI -> identification and configuration data
Program: WDTSR is a driver for the bitWatch watchdog hardware by bit-design
	  GmbH
SeeAlso: AH=2Bh/CX=6269h"bitFOSSI",INT 14/AH=14h"FOSSIL",INT 15/AH=C3h

INT 21 - bitFOSS - INSTALLATION CHECK
	AH = 2Bh
	CX = 6269h ('bi')
	DX = 7446h ('tF')
Return: AL = FFh if not installed
	AL = 4Fh ('O') if bitFOSS is installed
	    CX = 5353h ('SS')
	    DX = 494Ch ('IL')
	    ES = resident code segment
	    ES:DI -> identification data
Program: bitFOSS is a revision 5 FOSSIL driver
SeeAlso: AH=2Bh/CX=6269h"bitFOSSI",INT 11/AH=BCh

INT 21 - bitFOSSI - INSTALLATION CHECK
	AH = 2Bh
	CX = 6269h ('bi')
	DX = 7449h ('tI')
Return: AL = FFh if not installed
	AL = 53h ('S') if bitFOSSI is installed
	    CX = 444Eh ('DN')
	    DX = 2D46h ('-F')
	    ES = resident code segment
	    ES:DI -> identification data
Program: bitFOSSI is a revision 5 FOSSIL driver for ???'s ISDN board
SeeAlso: AH=2Bh/CX=6269h"bitFOSS",INT 11/AH=BCh

INT 21 - DOS 1+ - GET SYSTEM TIME
	AH = 2Ch
Return: CH = hour
	CL = minute
	DH = second
	DL = 1/100 seconds
Note:	on most systems, the resolution of the system clock is about 5/100sec,
	  so returned times generally do not increment by 1
	on some systems, DL may always return 00h
SeeAlso: AH=2Ah,AH=2Dh,AH=E7h"Novell",INT 1A/AH=00h,INT 1A/AH=02h,INT 1A/AH=FEh
SeeAlso: INT 2F/AX=120Dh

INT 21 - VIRUS - "Anti Pode 2.0" - INSTALLATION CHECK
	AH = 2Ch
Return: DL = F2h if resident
SeeAlso: AX=1812h"VIRUS",AX=2C2Ch

INT 21 - SKUDO - INSTALLATION CHECK
	AX = 2C00h
	CX = 534Bh ('SK')
	DX = 5544h ('UD')
	BX = 4F21h ('O!')
Return: AX = 5349h ('SI') if installed
	    CH = version number
	    CL = subversion
Program: SKUDO is an antivirus TSR by Jordi Mas

INT 21 - VIRUS - "LockJaw/Proto-T" - INSTALLATION CHECK
	AX = 2C2Ch
Return: AX = 0DCDh if resident
SeeAlso: AH=2Ch"VIRUS",AX=3000h"VIRUS"

INT 21 - DOS 1+ - SET SYSTEM TIME
	AH = 2Dh
	CH = hour
	CL = minute
	DH = second
	DL = 1/100 seconds
Return: AL = result
	    00h successful
	    FFh invalid time, system time unchanged
Note:	DOS 3.3+ also sets CMOS clock; due to the limitations of the CLOCK$
	  driver interface, the CMOS date is also updated to the current
	  DOS date
SeeAlso: AH=2Bh"DOS",AH=2Ch,INT 1A/AH=01h,INT 1A/AH=03h,INT 1A/AH=FFh"AT&T"

INT 21 - PC-Mix - INSTALLATION CHECK
	AX = 2D01h
	CX = 7820h ('X ')
	DX = 6D69h ('MI')
Return: AL = 00h if installed

INT 21 - DOS 1+ - SET VERIFY FLAG
	AH = 2Eh
	DL = 00h (DOS 1.x/2.x only)
	AL = new state of verify flag
	    00h off
	    01h on
Notes:	default state at system boot is OFF
	when ON, all disk writes are verified provided the device driver
	  supports read-after-write verification
SeeAlso: AH=54h

INT 21 - DOS 2+ - GET DISK TRANSFER AREA ADDRESS
	AH = 2Fh
Return: ES:BX -> current DTA
Note:	under the FlashTek X-32 DOS extender, the pointer is in ES:EBX
SeeAlso: AH=1Ah

INT 21 - DOS 2+ - GET DOS VERSION
	AH = 30h
---DOS 5+ ---
	AL = what to return in BH
	    00h OEM number (see #01394)
	    01h version flag
Return: AL = major version number (00h if DOS 1.x)
	AH = minor version number
	BL:CX = 24-bit user serial number (most versions do not use this)
---if DOS <5 or AL=00h---
	BH = MS-DOS OEM number (see #01394)
---if DOS 5+ and AL=01h---
	BH = version flag
	    bit 3: DOS is in ROM
	    other: reserved (0)
Notes:	the OS/2 v1.x Compatibility Box returns major version 0Ah (10)
	the OS/2 v2.x Compatibility Box returns major version 14h (20)
	OS/2 Warp 3.0 Virtual DOS Machines report v20.30; Warp 4 VDMs report
	  v20.40.
	the Windows NT DOS box returns version 5.00, subject to SETVER
	DOS 4.01 and 4.02 identify themselves as version 4.00; use
	  INT 21/AH=87h to distinguish between the original European MS-DOS 4.0
	  and the later PC-DOS 4.0x and MS-DOS 4.0x
	IBM DOS 6.1 reports its version as 6.00; use the OEM number to
	  distinguish between MS-DOS 6.00 and IBM DOS 6.1 (there was never an
	  IBM DOS 6.0)
	IBM's PC DOS 7 and Y2K updates report themselves as IBM 7.0 to be
	  distinguished from the MS-DOS 7.0 portion of Windows 95.
	MS-DOS 6.21 reports its version as 6.20; version 6.22 returns the
	  correct value
	Windows95 returns version 7.00 (the underlying MS-DOS), as did the
	  "Chicago" beta (reported in _Microsoft_Systems_Journal_,August 1994);
	  Windows95 OSR2 and OSR2.5 (OPK3) return MS version 7.10
	DR DOS 5.0 and 6.0 report version 3.31; Novell DOS 7 reports IBM v6.00,
	  which some software displays as IBM DOS v6.10 (because of the version
	  mismatch in true IBM DOS, as mentioned above).  The Novell DOS 7
	  SETVER.EXE has an undocumented option /G x.y which sets the "global"
	  DOS version returned by this function for all executables not given
	  a specific version number in SETVER to major version x and minor
	  version y.
	Heiko Goeman's Advanced WinDOS 2.10/2.11/2.21 returns "IBM" DOS 5.00
	  (subject to SETVER) and serial number 0.
	All versions of CCI Multiuser DOS up to "CCI Multiuser DOS 7.22 Gold"
	  as of 1997-02-10 report DOS 3.31.
	DR DOS 3.31, 3.32, 3.33, 3.34, 3.35, 3.40, 3.41, 5.0, 6.0 and
	  DR PalmDOS/NetWare PalmDOS 1.0 report version 3.31;
	  DR DOS "Panther" BETA 1 and "StarTrek" report as 5.0.
	  Novell DOS 7, OpenDOS 7.01, DR-OpenDOS 7.02, DR-DOS 7.02, DR-DOS 7.03
	  all report themselves as IBM 6.00, which some software displays as
	  IBM DOS 6.10 (because of the version mismatch in true IBM DOS,
	  as mentioned above). Use INT 21/AX=4452h to distinguish the DR-DOS
	  family from PC DOS.
	The Novell DOS 7 and OpenDOS 7.01 SETVER.EXE has an undocumented
	  option /G x.y which sets the "global" DOS version returned by this
	  function for all executables not given a specific version number in
	  SETVER to major version x >= 5 and minor version y = 0..254,
	  y = 255 is used to disable the BDOS version check at INT 21/AX=4452h.
	A slightly modified option has been documented for DR-OpenDOS 7.02+:
	  in /X mode it now allows for x >= 1, while y >= 100 requires /X mode,
	  and y >= 128 is used to control advanced version control means now
	  (see below).
	DR-DOS 7.02+ IBMDOS.COM (since 1998-01-10) now recognizes optional
	  paths to filenames stored in the SETVER list. Previously such entries
	  were never found. This allows for a three staged model for SETVERed
	  versions:
	  highest priority = entry with path is matching.
	  middle priority = entry without path is matching.
	  lowest priority = use global version (SETVER /G).
	The DR-DOS 7.02+ SETVER 1.01+ (1998-01-12) has also been enhanced to
	  allow DOS *and* BDOS version faking (see INT 21/AX=4452h): In /X mode,
	  setting a sub-version of y = 128..255 will be reported as 0..127 DOS
	  sub-version, sub-versions of y = 100..127 will instead be used to
	  report this value as BDOS version (64h..7Fh) via INT 21/AX=4452h, and
	  the DOS revision stored in PCM_HEADER in the IBMDOS.COM file will
	  be used to report the DOS sub-version (usually this holds 0, but it
	  can be patched to other values, see INT 21/AX=4452h !!!).
	  Note, that DR-DOS SHARE 2.05+ (1998-01-05) has relaxed version
	  checking, and will install on any DOS revision 0..127, as long as
	  run on a DR-DOS 72h+ kernel (formerly it was bound to a revision
	  byte of 0 only).
	Under Novell DOS 7+, the SETVERing also affects the version number
	  WORD stored at offset +40h in each program's PSP (see #01378).
	  This holds true even for special sub-versions of 100..255
	  (see INT 21/AX=4452h).
	generic MS-DOS 3.30, Compaq MS-DOS 3.31, and others identify themselves
	  as PC-DOS by returning OEM number 00h
	the version returned under DOS 4.0x may be modified by entries in
	  the special program list (see #01662 at AH=52h); the version returned
	  under DOS 5+ may be modified by SETVER--use AX=3306h to get the true
	  version number
SeeAlso: AX=3000h/BX=3000h,AX=3306h,AX=4452h,AH=87h,INT 15/AX=4900h
SeeAlso: AH=20h"S/DOS",INT 2F/AX=122Fh,INT 2F/AX=4010h,INT 2F/AX=4A33h
SeeAlso: INT 2F/AX=E002h

(Table 01394)
Values for DOS OEM number:
 00h *	IBM
     -	(Novell DOS, Caldera OpenDOS, DR-OpenDOS, and DR-DOS 7.02+ report IBM
	  as their OEM)
 01h *	Compaq
 02h *	MS Packaged Product
 04h *	AT&T
 05h *	ZDS (Zenith Electronics, Zenith Electronics)
	Note:	Zenith DOS 3.30 supports >32MB hard disks; this OEM ID can be
		  used to detect that support
 06h *	Hewlett-Packard
 07h *	Zenith Data Systems (ZDS, Groupe Bull), for DOS 5.0+
 08h *	Tandon
 09h *	AST (AST Europe Ltd.)
 0Ah *	Asem
 0Bh *	Hantarex
 0Ch *	SystemsLine
 0Dh *	Packard-Bell
 0Eh *	Intercomp
 0Fh *	Unibit
 10h *	Unidata
 16h *	DEC
 17h *	Olivetti DOS
 23h *	Olivetti (may have been a typo, since 23 = 17h)
 28h *	Texas Instruments
 29h *	Toshiba
 33h -	Novell (Windows/386 device IDs only)
 34h *	MS Multimedia Systems (Windows/386 device IDs only)
 35h *	MS Multimedia Systems (Windows/386 device IDs only)
 4Dh *	Hewlett-Packard (HP)
 5Eh -	RxDOS (Api Software & Mike Podanoffsky)	 http://www.freedos.org/
 66h -	PhysTechSoft (PTS-DOS)	http://www.phystechsoft.com/
	probably Paragon Technology Systems Corporation PTS-DOS as well
 99h -	General Software's Embedded DOS
 CDh -	Paragon Technology Systems Corporation ("Source DOS" S/DOS 1.0+)
	(see also INT 21/AH=20h"S/DOS")
 EDh -	reserved for future OpenDOS/DR-DOS based projects  http://www.drdos.org
 EEh	DR DOS
 EFh	Novell DOS
	Note:	released versions of Novell DOS 7 use OEM ID 00h instead
 FDh	FreeDOS	 http://www.freedos.org/
 FFh *	Microsoft, Phoenix (listed as "undefined" by Microsoft)
Notes:	'*' indicates an OEM release of MS-DOS, while '-' indicates an OEM
	  number used by a non-Microsoft DOS
	known OEM releases of MS-DOS:
	    AT&T DOS 3.10 (uses DOS 2.x cluster sizes and FAT structures)
	    Commodore DOS 3
	    Compaq DOS 3.31 (>32MB partitions similar to MS-DOS 4+)
	    Computerland DOS 3.10 (mix of DOS 2.x and 3.x disk mechanisms)
	    Eagle MS-DOS 1.25 (DOS 1.x with some hard disk support and built-in
		  ANSI.SYS functionality)
	    Epson Equity III DOS 3.10 (different clustering)
	    Leading Edge
	    NEC DOS 3.3
	    Olivetti DOS 2.11
	    Phoenix DOS 3.3, 4.01
	    Sanyo DOS 3.2
	    Tandy
	    Toshiba DOS
	    Unisys
	    Wyse MS-DOS 3
	    Zenith DOS 2.x (uses Zenith disk mechanism, extra drives at G:)
	    Zenith DOS 3.x (can be configured for Zenith or MS-DOS mechanism)
	    Zenith DOS 3.3 PLUS (>32MB partitions similar to MS-DOS 4+)

INT 21 - Phar Lap 386/DOS-Extender, Intel Code Builder - INSTALLATION CHECK
	AH = 30h
	EAX = 00003000h
	EBX = 50484152h ("PHAR")
Return: AL = major DOS version
	AH = minor DOS version
	EAX bits 31-16 = 4458h ('DX') if 386/DOS-extender installed
	    BL = ASCII major version number
	EAX bits 31-16 = 4243h ('BC') if Intel Code Builder installed
	    EDX = address of GDA
SeeAlso: AX=2501h,AX=FF00h,INT 2F/AX=F100h

INT 21 - VIRUS - "Possessed" - INSTALLATION CHECK
	AH = 30h
	DX = ABCDh
Return: DX = DCBAh if installed
SeeAlso: AX=0D20h,AH=30h/SI=1234h,AX=3000h"VIRUS",AX=30F1h

INT 21 - VIRUS - "ANDROMEDA-758" -INSTALLATION CHECK
	AH = 30h
	SI = 1234h
Return: AX = FFDDh if resident
SeeAlso: AH=30h/DX=ABCDh,AX=3000h"VIRUS"

INT 21 - CTask 2.0+ - INSTALLATION CHECK
	AX = 3000h
	BX = 1234h
	DS:DX -> 8-byte version string (DX < FFF0h) "CTask21",00h for v2.1-2.2
Return: AL = DOS major version
	AH = DOS minor version
	CX:BX -> Ctask global data block
Program: CTask is a multitasking kernel for C written by Thomas Wagner
Note:	if first eight bytes of returned data block equal eight bytes passed
	  in, CTask is resident

INT 21 - PC-MOS/386 v3.0 - INSTALLATION CHECK/GET VERSION
	AX = 3000h
	BX = 3000h
	CX = DX = 3000h
Return: AX = PC-MOS version
Program: PC-MOS/386 is a multitasking/multiuser MS-DOS-compatible operating
	  system by The Software Link, Inc.
SeeAlso: AH=30h,INT D4/AH=02h,INT D4/AH=10h

INT 21 - VIRUS - "Jackal" - INSTALLATION CHECK
	AX = 3000h
	BX = 614Ah ('aJ')
	CX = 6B63h ('kc')
	DX = 6C61h ('la')
Return: BX = ???
SeeAlso: AX=2C2Ch"VIRUS",AX=3030h"VIRUS"

INT 21 - StopPrg v2.0 - INSTALLATION CHECK
	AX = 3022h
Return: AX = DOS version (see AH=30h)
	CX = 1112h if StopPrg installed
	    BX = segment of resident code
Program: StopPrg is a resident program aborter by MAK-TRAXON's Prophet
Note:	StopPrg may be temporarily disabled by storing 9090h in the word at
	  0000h:04FEh

INT 21 - VIRUS - "IMTC" -INSTALLATION CHECK
	AX = 3030h
	BX = 694Dh
Return: DX = 7443h if resident
SeeAlso: AX=3000h/BX=614Ah"VIRUS",AX=3032h"VIRUS"

INT 21 - VIRUS - "Uruguay" - INSTALLATION CHECK
	AX = 3032h
	DX = 1234h
Return: AX = 5678h if resident
SeeAlso: AX=3030h"VIRUS",AX=30F1h"VIRUS"

INT 21 - VIRUS - "Dutch-555"/"Quit 1992" - INSTALLATION CHECK
	AX = 30F1h
Return: AL = 00h if resident
SeeAlso: AH=30h/DX=ABCDh,AX=3032h,AX=330Fh,AX=33DAh

INT 21 - DESQ??? - INSTALLATION CHECK
	AX = 30FFh
	CX = 4445h ("DE")
	DX = 5351h ("SQ")
Return: BH = 05h if installed
	???
Note:	called by DUBLDISK.COM v2.6; this function is not supported by
	  DESQview, so it may be for DESQview's precursor DESQ.
SeeAlso: AX=4404h"DUBLDISK"

INT 21 - DOS 2+ - TERMINATE AND STAY RESIDENT
	AH = 31h
	AL = return code
	DX = number of paragraphs to keep resident
Return: never
Notes:	the value in DX only affects the memory block containing the PSP;
	  additional memory allocated via AH=48h is not affected
	the minimum number of paragraphs which will remain resident is 11h
	  for DOS 2.x and 06h for DOS 3.0+
	most TSRs can save some memory by releasing their environment block
	  before terminating (see #01378 at AH=26h,AH=49h)
	any open files remain open, so one should close any files which will
	  not be used before going resident; to access a file which is left
	  open from the TSR, one must switch PSP segments first (see AH=50h)
SeeAlso: AH=00h,AH=4Ch,AH=4Dh,INT 20,INT 22,INT 27

INT 21 - DOS 2+ - GET DOS DRIVE PARAMETER BLOCK FOR SPECIFIC DRIVE
	AH = 32h
	DL = drive number (00h = default, 01h = A:, etc)
Return: AL = status
	    00h successful
		DS:BX -> Drive Parameter Block (DPB) (see #01395) for specified
			  drive
	    FFh invalid or network drive
Notes:	the OS/2 compatibility box supports the DOS 3.3 version of this call
	  except for the DWORD at offset 12h
	this call updates the DPB by reading the disk; the DPB may be accessed
	  via the DOS list of lists (see #01627 at AH=52h) if disk access is not
	  desirable.
	undocumented prior to the release of DOS 5.0; only the DOS 4.0+
	  version of the DPB has been documented, however
	supported by DR DOS 3.41+; DR DOS 3.41-6.0 return the same data as
	  MS-DOS 3.31
	IBM ROM-DOS v4.0 also reports invalid/network (AL=FFh) on the ROM drive
SeeAlso: AH=1Fh,AH=52h,AX=7302h

Format of DOS Drive Parameter Block:
Offset	Size	Description	(Table 01395)
 00h	BYTE	drive number (00h = A:, 01h = B:, etc)
 01h	BYTE	unit number within device driver
 02h	WORD	bytes per sector
 04h	BYTE	highest sector number within a cluster
 05h	BYTE	shift count to convert clusters into sectors
 06h	WORD	number of reserved sectors at beginning of drive
 08h	BYTE	number of FATs
 09h	WORD	number of root directory entries
 0Bh	WORD	number of first sector containing user data
 0Dh	WORD	highest cluster number (number of data clusters + 1)
		16-bit FAT if greater than 0FF6h, else 12-bit FAT
 0Fh	BYTE	number of sectors per FAT
 10h	WORD	sector number of first directory sector
 12h	DWORD	address of device driver header (see #01646)
 16h	BYTE	media ID byte (see #01356)
 17h	BYTE	00h if disk accessed, FFh if not
 18h	DWORD	pointer to next DPB
---DOS 2.x---
 1Ch	WORD	cluster containing start of current directory, 0000h=root,
		FFFFh = unknown
 1Eh 64 BYTEs	ASCIZ pathname of current directory for drive
---DOS 3.x---
 1Ch	WORD	cluster at which to start search for free space when writing
 1Eh	WORD	number of free clusters on drive, FFFFh = unknown
---DOS 4.0-6.0---
 0Fh	WORD	number of sectors per FAT
 11h	WORD	sector number of first directory sector
 13h	DWORD	address of device driver header (see #01646)
 17h	BYTE	media ID byte (see #01356)
 18h	BYTE	00h if disk accessed, FFh if not
 19h	DWORD	pointer to next DPB
 1Dh	WORD	cluster at which to start search for free space when writing,
		usually the last cluster allocated
 1Fh	WORD	number of free clusters on drive, FFFFh = unknown
SeeAlso: #01357,#01663,#01787 at AX=7302h,#04039 at INT E0/CL=71h

INT 21 - DOS 2+ - EXTENDED BREAK CHECKING
	AH = 33h
	AL = subfunction
	    00h get current extended break state
		Return: DL = current state, 00h = off, 01h = on
	    01h set state of extended ^C/^Break checking
		DL = new state
		    00h off, check only on character I/O functions
		    01h on, check on all DOS functions
		Return: (Novell DOS 7) DL = old state of extended Break checks
Note:	under DOS 3.1+ and DR DOS, this function does not use any of the
	  DOS-internal stacks and may thus be called at any time
SeeAlso: AX=3302h

INT 21 - DOS 3.x+ internal - GET AND SET EXTENDED CONTROL-BREAK CHECKING STATE
	AX = 3302h
	DL = new state (00h for OFF, 01h for ON)
Return: DL = old state of extended BREAK checking
Notes:	this function does not use any of the DOS-internal stacks and may thus
	  be called at any time; one possible use is modifying Control-Break
	  checking from within an interrupt handler or TSR
	not supported by DR DOS through version 6.0 (error code 01h);
	  newly-supported by Novell DOS 7
SeeAlso: AH=33h

INT 21 - DOS 3.4/4.0 - GET CURRENT CPSW STATE
	AX = 3303h
Return: DL = current CPSW
Notes:	this function and AX=3304h were intended to support a proposed
	  code-page switching flag (using the WORD at offset 0Ch in the DOS
	  directory entry for codepage information); however, this function
	  has always been a NOP in public releases of DOS and OS/2.
	  See _DOS_Internals_ Chapter 2 for more information.
	the released MS-DOS 4.00 IO.SYS has an undocumented CONFIG.SYS
	  directive named CPSW= and that beside others the MS-DOS 4.00 ATTRIB
	  supported a number of undocumented special parameters for
	  "predefined" Extended Attributes (EAs) e.g.
	  ATTRIB filename [(CODEPAGE|CP)[=new_value]].
	this function does not use any of the DOS-internal stacks and may
	   thus be called at any time. It is directly dispatched from
	   the INT 21h entry point with interrupts disabled.
SeeAlso: AX=3304h

INT 21 - DOS 3.4/4.0 - SET CPSW STATE
	AX = 3304h
	DL = new CPSW state
Return: nothing
Notes:	this function and AX=3303h were intended to support a proposed
	  code-page switching flag (using the WORD at offset 0Ch in the DOS
	  directory entry for codepage information); however, this function
	  has always been a NOP in public releases of DOS and OS/2.
	  See _DOS_Internals_ Chapter 2 for more information.
	the released MS-DOS 4.00 IO.SYS has an undocumented CONFIG.SYS
	  directive named CPSW= and that beside others the MS-DOS 4.00 ATTRIB
	  supported a number of undocumented special parameters for
	  "predefined" Extended Attributes (EAs) e.g.
	  ATTRIB filename [(CODEPAGE|CP)[=new_value]].
	this function does not use any of the DOS-internal stacks and may
	   thus be called at any time. It is directly dispatched from
	   the INT 21h entry point with interrupts disabled.
SeeAlso: AX=3303h,AH=11h,AX=5702h

INT 21 - DOS 4.0+ - GET BOOT DRIVE
	AX = 3305h
Return: DL = boot drive (1=A:,...)
Notes:	This function does not use any of the DOS-internal stacks and may
	   thus be called at any time.  It is directly dispatched from
	   the INT 21h entry point with interrupts disabled.
	NEC 9800-series PCs always call the boot drive A: and assign the other
	  drive letters sequentially to the other drives in the system
	this call is supported by OS/2 Warp 3.0, but not earlier versions of
	  OS/2; it is also supported by Novell DOS 7

INT 21 - DOS 5+ - GET TRUE VERSION NUMBER
	AX = 3306h
Return: BL = major version
	BH = minor version
	DL = revision (bits 2-0, all others 0)
	DH = version flags
	    bit 3: DOS is in ROM
	    bit 4: DOS is in HMA
	AL = FFh if true DOS version < 5.0
Notes:	this function always returns the true version number, unlike AH=30h,
	  whose return value may be changed with SETVER
	because of the conflict from the CBIS redirector (see next
	  entry), programs should check whether BH is less than 100 (64h)
	  and BL is at least 5 before accepting the returned BX as the true
	  version number; however, even this is not entirely reliable when
	  that redirector is loaded
	Under MS-DOS/PC DOS, DR DOS, PTS-DOS, S/DOS this function does not
	  use any of the DOS internal stacks and thus is fully reentrant
	OS/2 v2.1 will return BX=0A14h (version 20.10)
	Windows 95 and Windows 95 SP1 return version 7.00; Windows 95 OSR2
	  and OPK3 (OSR2.5) return version MS 7.10.
	the Windows NT DOS box returns BX=3205h (version 5.50)
	Novell DOS 7 returns IBM v6.00, which some software displays as
	  IBM DOS v6.10 (because of the version mismatch in true IBM DOS
	  mentioned for INT 21/AH=30h); versions through Update 15 all
	  return revision code 00h
	Windows95 and Windows95 SP1 return version 7.00; Windows95 OSR2 returns
	  version 7.10
	Heiko Goeman's Advanced WinDOS 2.10/2.11/2.21 returns DOS 5.00, 
	  revision 0.
	Novell DOS 7, OpenDOS 7.01, DR-OpenDOS 7.02, DR-DOS 7.02, DR-DOS 7.03
	  all return IBM 6.00, which some software displays as IBM DOS 6.10
	  (because of the version mismatch in true IBM DOS mentioned for
	  INT 21/AH=30h); versions through Novell DOS 7 Update 15.2 (01/1996)
	  all return revision code 00h. The DOS revision is stored in bits 7-0
	  of the "patch_version" field in the PCM_HEADER structure in the
	  IBMDOS.COM file (see also INT 21/AX=4452h !!!). The version
	  flags (DH) are stored in bits 15-8 of "patch_version", but is updated
	  at runtime to reflect the actual status. "patch_version" is also
	  reported as DX in INT 21/AX=4452h.
	Unlike MS-DOS, under Novell DOS 7+ IBMDOS.COM will also allow to
	  SETVER the returned "true" DOS version same as with INT 21/AX=3000h
	  and INT 21/AX=3001h.
	DR-DOS 7.02+ IBMDOS.COM (since 1998-01-10) now recognizes optional
	  paths to filenames stored in the SETVER list. Previously such
	  entries were never found. This enables a three staged model of
	  SETVERed versions:
	  highest priority = entry with path is matching.
	  middle priority = entry without path is matching.
	  lowest priority = use global version (SETVER /G).
	The DR-DOS 7.02+ SETVER 1.01+ (1998-01-12) has also been enhanced to
	  allow BDOS and DOS version faking (see INT 21/AX=4452h). In /X mode,
	  a set sub-version of y = 128..255 will be reported as 0..127 DOS
	  sub-version, sub-versions of y = 100..127 will be used to report this
	  value as BDOS version (64h..7Fh) with INT 21/AX=4452h instead while
	  bits 6-0 of the DOS revision stored in PCM_HEADER in the IBMDOS.COM
	  file will be used to report the BH DOS sub-version 0..127 (usually
	  this holds 0, but it can be patched to other values).
	DR-DOS SHARE 2.05 (1998-01-05) has relaxed version checking now, and
	  will install on any DOS revision 0..127 (formerly it was bound to
	  DOS revision 0 only), as long as run on a DR-DOS 72h or 73h BDOS
	  kernel.  Hence, if there will be changes in the SHARE implementation
	  without changing the BDOS version, DR-DOS SHARE 2.05 can still be
	  stopped from installing by changing the DOS revision in PCM_HEADER
	  to something in the range 128..255.
	Under Novell DOS 7+, the version SETVERing also affects the version
	  number WORD stored at offset +40h in each program's PSP (see
	  Table xxxx at INT 21/AH=26h). This holds true even for special
	  sub-versions of 100..255 (see INT 21/AX=4452h).
	S/DOS 1.0 (1995) returns a DOS revision of 9, while its own PTS OEM
	  revision still defaults to 0 (see also INT 21/AH=20h"S/DOS").
BUG:	DR DOS 5.0 and 6.0 return CF set/AX=0001h for INT 21/AH=33h
	  subfunctions other than 00h-02h and 05h, while MS-DOS returns AL=FFh
	  for invalid subfunctions
SeeAlso: AH=30h,INT 2F/AX=122Fh,INT 2F/AX=E000h"SETDRVER"

INT 21 - CBIS network - NETWORK REDIRECTOR - ???
	AX = 3306h
Return: AX = 3306h
	BL = ??? (usually 00h)
	BH = ??? (usually 00h or FFh)
Note:	unknown function, is in conflict with DOS 5+ version call
SeeAlso: AX=3306h"DOS"

INT 21 - Windows95 - SET/CLEAR DOS_FLAG
	AX = 3307h
	DL = subfunction
	    00h clear bit 5 of "DOS_FLAG"
	    01h set bit 5 of "DOS_FLAG"
Return: ???

INT 21 - VIRUS - "Burghofer" - INSTALLATION CHECK
	AX = 330Fh
Return: AL = 0Fh if resident (DOS returns AL=FFh)
SeeAlso: AX=30F1h,AX=33DAh,AX=33E0h

INT 21 - Diet Disk v1.0 - INSTALLATION CHECK
	AX = 3341h
Return: DX = 1234h if installed
	    CX = resident code segment
Program: Diet Disk is a public domain transparent data file compressor by
	  Barry Nance

INT 21 - VIRUS - "CoffeeShop" - INSTALLATION CHECK
	AX = 33DAh
Return: AH = A5h if resident
	    AL = virus version
SeeAlso: AX=33DB,AX=33DCh,AX=330Fh,AX=33E0h,AX=5643h"VIRUS"

INT 21 - VIRUS - "CoffeeShop" - GENERATE RANDOM NUMBER
	AX = 33DBh
Return:	???
SeeAlso: AX=33DAh,AX=33DCh

INT 21 - VIRUS - "CoffeeShop" - DISPLAY "LEGALIZE CANNABIS" GRAPHIC
	AX = 33DCh
Return:	???
SeeAlso: AX=33DAh,AX=33DBh

INT 21 - VIRUS - "Oropax" - INSTALLATION CHECK
	AX = 33E0h
Return: AL = E0h if resident (DOS returns AL=FFh)
SeeAlso: AX=330Fh,AX=33DAh,AX=357Fh

INT 21 - DOS 2+ - GET ADDRESS OF INDOS FLAG
	AH = 34h
Return: ES:BX -> one-byte InDOS flag
Notes:	this function executes on the DOS stack, and thus cannot be called
	  while another DOS function is already executing; you should use
	  this function once at the beginning of the program and store the
	  returned pointer rather than calling it when requiring DOS access
	the value of InDOS is incremented whenever an INT 21 function begins
	  and decremented whenever one completes
	during an INT 28 call, it is safe to call some INT 21 functions even
	  though InDOS may be 01h instead of zero
	InDOS alone is not sufficient for determining when it is safe to
	  enter DOS, as the critical error handling decrements InDOS and
	  increments the critical error flag for the duration of the critical
	  error.  Thus, it is possible for InDOS to be zero even if DOS is
	  busy.
	SMARTDRV 4.0 sets the InDOS flag while flushing its buffers to disk,
	  then zeros it on completion
	the critical error flag is the byte immediately following InDOS in
	  DOS 2.x, and the byte BEFORE the InDOS flag in DOS 3.0+ and
	  DR DOS 3.41+ (except COMPAQ DOS 3.0, where the critical error flag
	  is located 1AAh bytes BEFORE the critical section flag)
	for DOS 3.1+, an undocumented call exists to get the address of the
	  critical error flag (see AX=5D06h)
	this function was undocumented prior to the release of DOS 5.0.
SeeAlso: AX=5D06h,AX=5D0Bh,INT 15/AX=DE1Fh,INT 28

INT 21 - DOS 2+ - GET INTERRUPT VECTOR
	AH = 35h
	AL = interrupt number
Return: ES:BX -> current interrupt handler
Note:	under DR DOS 5.0+, this function does not use any of the DOS-internal
	  stacks and may thus be called at any time
SeeAlso: AH=25h,AX=2503h

INT 21 P - FlashTek X-32VM - ALLOCATE PROTECTED-MODE SELECTOR
	AX = 3501h
Return: CF clear if successful
	    BX = new selector
	CF set on error (no more selectors available)
Note:	the new selector will be an expand-up read/write data selector with
	  undefined base and limit
SeeAlso: AX=3502h,INT 31/AX=0000h

INT 21 P - FlashTek X-32VM - DEALLOCATE PROTECTED-MODE SELECTOR
	AX = 3502h
	BX = selector
Return: CF clear if successful
	CF set on error (invalid selector)
Note:	only selectors allocated via AX=3501h should be deallocated
SeeAlso: AX=3501h,INT 31/AX=0001h

INT 21 P - FlashTek X-32VM - SET SELECTOR BASE ADDRESS
	AX = 3503h
	BX = selector
	ECX = base address
Return: CF clear if successful
	CF set on error (invalid selector)
SeeAlso: AX=3504h,AX=3505h,INT 31/AX=0007h

INT 21 P - FlashTek X-32VM - GET SELECTOR BASE ADDRESS
	AX = 3504h
	BX = selector
Return: CF clear if successful
	    ECX = absolute base address of selector
	CF set on error (invalid selector)
SeeAlso: AX=3503h,INT 31/AX=0006h

INT 21 P - FlashTek X-32VM - SET SELECTOR LIMIT
	AX = 3505h
	BX = selector
	ECX = desired limit
Return: CF clear if successful
	    ECX = actual limit set
	CF set on error (no more selectors available)
Note:	the limit will be rounded down to nearest 4K boundary if the requested
	  limit is greater than 1MB
SeeAlso: AX=3503h,INT 31/AX=0008h

INT 21 P - FlashTek X-32VM - PHYSICAL ADDRESS MAPPING
	AX = 350Ah
	EBX = absolute physical address
	ECX = size in bytes of area to map
Return: CF clear if successful
	CF set on error (insufficient memory or service refused by DPMI host)
Notes:	should not make repeated calls for the same physical address
	there is no provision for unmapping memory

INT 21 P - FlashTek X-32VM - UPDATE AND RETURN AVAILABLE FREE MEMORY
	AX = 350Bh
	DS = default selector for DS
Return: CF clear
	EAX = maximum amount of memory which can be allocated via AX=350Ch
SeeAlso: AX=350Ch

INT 21 P - FlashTek X-32VM - ALLOCATE A BLOCK OF MEMORY
	AX = 350Ch
	ECX = size of block in bytes
	DS = default DS
Return: CF clear if successful
	    EAX = near pointer to new block
	    EDX = new lowest legal value for stack
	CF set on error (requested size not multiple of 4K)
SeeAlso: AX=350Bh,AX=350Dh

INT 21 P - FlashTek X-32VM - RESERVE BLOCK OF MEMORY FOR 32-BIT STACK
	AX = 350Dh
	EBX = current ESP value
	ECX = size of block in bytes
	DS = default DS
Return: CF clear if successful
	    EBX = new value for ESP
	    EDX = suggested new limit for SS
	CF set on error
Note:	this function should only be called once during initialization
SeeAlso: AX=350Bh,AX=350Ch

INT 21 - VIRUS - "Agiplan"/"Month 4-6" - INSTALLATION CHECK
	AX = 357Fh
Return: DX = FFFFh if installed
SeeAlso: AX=33E0h,AX=3DFFh

INT 21 - DOS 2+ - GET FREE DISK SPACE
	AH = 36h
	DL = drive number (00h = default, 01h = A:, etc)
Return: AX = FFFFh if invalid drive
	else
	    AX = sectors per cluster
	    BX = number of free clusters
	    CX = bytes per sector
	    DX = total clusters on drive
Notes:	free space on drive in bytes is AX * BX * CX
	total space on drive in bytes is AX * CX * DX
	"lost clusters" are considered to be in use
	according to Dave Williams' MS-DOS reference, the value in DX is
	  incorrect for non-default drives after ASSIGN is run
	this function does not return proper results on CD-ROMs;
	  use AX=4402h"CD-ROM" instead
	(FAT32 drive) the reported total and free space are limited to 2G-32K
	  should they exceed that value
SeeAlso: AH=1Bh,AH=1Ch,AX=4402h"CD-ROM",AX=7303h

INT 21 - DOS 2+ - "SWITCHAR" - GET SWITCH CHARACTER
	AX = 3700h
Return: AL = status
	    00h successful
		DL = current switch character
	    FFh unsupported subfunction
Desc:	Determine the character which is used to introduce command switches.
	  This setting is ignored by MS-DOS commands in version 4.0 and higher,
	  but is honored by many third-party programs and by Novell DOS 7
	  external commands
BUG:	Novell DOS 7's COMMAND.COM (prior to Update 15) fails to honor the
	  SwitChar setting for internal commands even though COMMAND.COM
	  honors it in its own command tail (i.e. COMMAND /?); even in Update
	  15, internal commands fail to honor SwitChar for the /? help option
Notes:	documented in some OEM versions of some releases of DOS
	supported by OS/2 compatibility box
	always returns AL=00h/DL=2Fh for MS-DOS 5+ and DR DOS 3.41-6.0
	Novell DOS 7 COMMAND.COM indicates switch characters other than '/'
	  by changing the first backslash (and only the first one) in the
	  path it prints for PROMPT $p with a forward slash
SeeAlso: AX=3701h

INT 21 - DOS 2+ - "SWITCHAR" - SET SWITCH CHARACTER
	AX = 3701h
	DL = new switch character
Return: AL = status
	    00h successful
	    FFh unsupported subfunction
Notes:	documented in some OEM versions of some releases of DOS; DOS 2.x had
	  a SWITCHAR=c setting in CONFIG.SYS
	supported by OS/2 compatibility box and Novell DOS 7
	ignored by MS-DOS 5+ and DR DOS 3.41-6.0; DR DOS 6.0 and Novell DOS 7
	  leave AX unchanged
SeeAlso: AX=3700h

INT 21 - DOS 2.x and 3.3+ only - "AVAILDEV" - SPECIFY \DEV\ PREFIX USE
	AH = 37h
	AL = subfunction
	    02h get availdev flag
		Return: DL = 00h \DEV\ must precede character device names
			   = nonzero \DEV\ is optional
	    03h set availdev flag
		DL = new state
		    00h		\DEV\ is mandatory
		    nonzero	\DEV\ is optional
Return: AL = status
	    00h successful
	    FFh unsupported subfunction
Notes:	all versions of DOS from 2.00 allow \DEV\ to be prepended to device
	  names without generating an error even if the directory \DEV does
	  not actually exist (other paths generate an error if they do not
	  exist); DOS 2.x has an AVAILDEV= option in CONFIG.SYS to make \DEV
	  mandatory
	although MS-DOS 3.3+, DR DOS 3.41+, and Novell DOS 7 accept these
	  calls, they have no effect, and AL=02h always returns DL=FFh (except
	  for Novell DOS 7, which leaves AX unchanged for both subfunctions)

INT 21 - XPACK v1.52+ - TSR INSTALLATION CHECK
	AX = 37A0h
	BX = 6A6Dh ('jm')
Return: AL = FFh if not present as TSR (default return value from DOS)
	AX = 0000h if installed as a TSR
	    CX = 6A6Dh ('jm')
	    DX = version ID (0152h)
Program: XPACK is a transparent file compressor/decompressor by JauMing Tseng
SeeAlso: AX=37A1h/BX=6A6Dh,AX=37A3h/BX=6A6Dh

INT 21 - XPACK v1.52+ - UNINSTALL
	AX = 37A1h
	BX = 6A6Dh ('jm')
Return: AX = status
	    0000h successful
	    FFFFh failed
Program: XPACK is a transparent file compressor/decompressor by JauMing Tseng
SeeAlso: AX=37A0h/BX=6A6Dh

INT 21 - XPACK v1.52+ - GET TSR STATUS
	AX = 37A2h
	BX = 6A6Dh ('jm')
Return: AX = 0000h (successful)
	DL = status (01h active, 00h disabled)
SeeAlso: AX=37A3h/BX=6A6Dh

INT 21 - XPACK v1.52+ - SET TSR STATUS
	AX = 37A3h
	BX = 6A6Dh ('jm')
	DL = status (01h active, 00h disabled)
Return: AX = 0000h (successful)
SeeAlso: AX=37A0h/BX=6A6Dh,AX=37A2h/BX=6A6Dh

INT 21 - XPACK v1.65 - GET TEMPORARY DIRECTORY NAME
	AX = 37A6h
	BX = 6A6Dh ('jm')
Return: AX = 0000h
	DS:DX -> name of temporary directory
Program: XPACK is a transparent file compressor/decompressor by JauMing Tseng
SeeAlso: AX=37A0h/BX=6A6Dh,AX=37A7h/BX=6A6Dh

INT 21 - XPACK v1.65 - SET TEMPORARY DIRECTORY NAME
	AX = 37A7h
	BX = 6A6Dh ('jm')
	DS:DX -> ASCIZ name of temporary directory (max 64 chars)
Return: AX = 0000h
Note:	the specified directory name must include a drive letter and end with
	  a backslash (e.g. 'c:\dos\',0)
SeeAlso: AX=37A0h/BX=6A6Dh,AX=37A6h/BX=6A6Dh

INT 21 - DIET v1.43e - TSR INSTALLATION CHECK
	AX = 37D0h
	BX = 899Dh ('DI' + 'ET')
Return: AL = FFh if not present as TSR (default return value from DOS)
	AX = 0000h if installed as a TSR
	    CX = 899Dh
	    DX = version ID
Program: DIET is a transparent file compressor/decompressor by Teddy Matsumoto
SeeAlso: AX=37D1h,AX=37D2h,AX=37D4h,AX=37D6h,AX=37DFh,AX=4BF0h,AX=4BF1h

INT 21 - DIET v1.43e - GET DIET.EXE RESIDENT SEGMENT
	AX = 37D1h
	BX = 899Dh ('DI' + 'ET')
Return: AX = 0000h
	CX = code segment of TSR part of DIET.EXE
	DX = memory block segment of TSR DIET.EXE
		(0000h if installed as device driver)
SeeAlso: AX=37D0h,AX=37DFh

INT 21 - DIET v1.43e - GET TSR CONTROL FLAGS
	AX = 37D2h
	BX = 899Dh ('DI' + 'ET')
Return: AX = 0000h
	DL = control flag (00h active, else disabled)
	DH = skip flag (nonzero while TSR active)
SeeAlso: AX=37D0h,AX=37D3h,AX=37D4h

INT 21 - DIET v1.43e - SET TSR CONTROL FLAGS
	AX = 37D3h
	BX = 899Dh ('DI' + 'ET')
	DL = control flag (00h active, else disabled)
	DH = skip flag (00h)
Return: AX = 0000h
SeeAlso: AX=37D0h,AX=37D2h,AX=37D5h

INT 21 - DIET v1.43e - GET TSR OPTIONS
	AX = 37D4h
	BX = 899Dh ('DI' + 'ET')
Return: AX = 0000h
	DX = TSR options (see #01396)
SeeAlso: AX=37D0h,AX=37D2h,AX=37D5h

Bitfields for DIET TSR options:
Bit(s)	Description	(Table 01396)
 0	automated compression of DIETed file
 1	automated compression of newly-created file
 2	suppress DIET message
 3	display original file size
 4-15	reserved (0)

INT 21 - DIET v1.43e - SET TSR OPTIONS
	AX = 37D5h
	BX = 899Dh ('DI' + 'ET')
	DX = TSR options (see #01396)
Return: AX = 0000h
Program: DIET is a transparent file compressor/decompressor by Teddy Matsumoto
SeeAlso: AX=37D0h,AX=37D3h,AX=37D4h

INT 21 - DIET v1.43e - GET TEMPORARY DIRECTORY NAMES
	AX = 37D6h
	BX = 899Dh ('DI' + 'ET')
Return: AX = 0000h
	DS:DX -> name of temporary directory or 0000h:0000h for current dir
SeeAlso: AX=37D0h,AX=37D7h

INT 21 - DIET v1.43e - SET TEMPORARY DIRECTORY NAMES
	AX = 37D7h
	BX = 899Dh ('DI' + 'ET')
	DS:DX -> ASCIZ name of temporary directory (max 61 chars)
		0000h:0000h for current directory
Return: AX = 0000h
Note:	the specified directory name must include a drive letter and end with
	  a backslash
SeeAlso: AX=37D0h,AX=37D6h

INT 21 - DIET v1.43e - SET ADDRESS OF EXTERNAL PROCEDURE
	AX = 37DCh
	BX = 899Dh ('DI' + 'ET')
	DS:DX -> external procedure (see #01397)
Return: AX = 0000h
Note:	the resident code will call the specified external procedure at the
	  beginning of decompression and when compression is exited on failure
SeeAlso: AX=37DDh

(Table 01397)
Values DIET external procedure is called with:
	STACK:	WORD	class
			FFFDh creation failed for unknown reasons
			FFFEh creation failed due to lack of space
			FFFFh file creation error
			else file handle of DIETed file to be decompressed
		DWORD	-> compressed filename
		DWORD	-> decompressed or temporary filename
Return: SI,DI,BP,DS,ES must be preserved by external procedure

INT 21 - DIET v1.43e - RELEASE EXTERNAL PROCEDURE
	AX = 37DDh
	BX = 899Dh ('DI' + 'ET')
Program: DIET is a transparent file compressor/decompressor by Teddy Matsumoto
Note:	unlinks the external procedure specified by AX=37DCh
SeeAlso: AX=37DCh

INT 21 - DIET v1.43e - READ EMS STATUS
	AX = 37DEh
	BX = 899Dh ('DI' + 'ET')
Return: AX = 0000h
	CX = EMS status
	    0000h not used
	    0001h used as work area
	    0002h used for code and as work area
	DX = EMM handle when EMS is in use

INT 21 - DIET v1.43e - UNINSTALL TSR
	AX = 37DFh
	BX = 899Dh ('DI' + 'ET')
Return: AX = status
	    0000h successful
	    00FFh failed
Program: DIET is a transparent file compressor/decompressor by Teddy Matsumoto
SeeAlso: AX=37D0h
Index:	uninstall;DIET

INT 21 - DOS 2+ - GET COUNTRY-SPECIFIC INFORMATION
	AH = 38h
--DOS 2.x--
	AL = 00h get current-country info
	DS:DX -> buffer for returned info (see #01398,#01399)
Return: CF set on error
	    AX = error code (02h)
	CF clear if successful
	    AX = country code (MS-DOS 2.11 only)
	    buffer at DS:DX filled
--DOS 3.0+--
	AL = 00h for current country
	AL = 01h thru 0FEh for specific country with code <255 (see #01400)
	AL = 0FFh for specific country with code >= 255
	   BX = 16-bit country code (see #01400)
	DS:DX -> buffer for returned info (see #01399)
Return: CF set on error
	    AX = error code (02h)
	CF clear if successful
	    AX = country code (Novell NWDOS v7.0)
	    BX = country code
	    DS:DX buffer filled
Note:	this function is not supported by the Borland DPMI host, but no error
	  is returned; as a workaround, one should allocate a buffer in
	  conventional memory with INT 31/AX=0100h and simulate an INT 21 with
	  INT 31/AX=0300h
SeeAlso: AH=65h,INT 10/AX=5001h,INT 2F/AX=1404h

Format of DOS 2.00-2.10 country info:
Offset	Size	Description	(Table 01398)
 00h	WORD	date format  0 = USA	mm dd yy
			     1 = Europe dd mm yy
			     2 = Japan	yy mm dd
 02h	BYTE	currency symbol
 03h	BYTE	00h
 04h	BYTE	thousands separator char
 05h	BYTE	00h
 06h	BYTE	decimal separator char
 07h	BYTE	00h
 08h 24 BYTEs	reserved

Format of DOS 2.11+ country info:
Offset	Size	Description	(Table 01399)
 00h	WORD	date format (see #01398)
 02h  5 BYTEs	ASCIZ currency symbol string
 07h  2 BYTEs	ASCIZ thousands separator
 09h  2 BYTEs	ASCIZ decimal separator
 0Bh  2 BYTEs	ASCIZ date separator
 0Dh  2 BYTEs	ASCIZ time separator
 0Fh	BYTE	currency format
		bit 2 = set if currency symbol replaces decimal point
		bit 1 = number of spaces between value and currency symbol
		bit 0 = 0 if currency symbol precedes value
			1 if currency symbol follows value
 10h	BYTE	number of digits after decimal in currency
 11h	BYTE	time format
		bit 0 = 0 if 12-hour clock
			1 if 24-hour clock
 12h	DWORD	address of case map routine
		(FAR CALL, AL = character to map to upper case [>= 80h])
 16h  2 BYTEs	ASCIZ data-list separator
 18h 10 BYTEs	reserved

(Table 01400)
Values for country code:
 001h (1)	United States
 002h (2)	Canadian-French
 003h (3)	Latin America
 004h (4)	Canada (English)
 007h (7)	Russia
 014h (20)	Egypt
 01Bh (27)	South Africa
 01Eh (30)	Greece
 01Fh (31)	Netherlands
 020h (32)	Belgium
 021h (33)	France
 022h (34)	Spain
 023h (35)	Bulgaria???
 024h (36)	Hungary (not supported by DR DOS 5.0)
 026h (38)	Yugoslavia (not supported by DR DOS 5.0) -- obsolete
 027h (39)	Italy / San Marino / Vatican City
 028h (40)	Romania
 029h (41)	Switzerland / Liechtenstein
 02Ah (42)	Czechoslovakia / Tjekia / Slovakia (not supported by DR DOS 5.0)
 02Bh (43)	Austria (DR DOS 5.0)
 02Ch (44)	United Kingdom
 02Dh (45)	Denmark
 02Eh (46)	Sweden
 02Fh (47)	Norway
 030h (48)	Poland (not supported by DR DOS 5.0)
 031h (49)	Germany
 033h (51)	Peru
 034h (52)	Mexico
 035h (53)	Cuba
 036h (54)	Argentina
 037h (55)	Brazil (not supported by DR DOS 5.0)
 038h (56)	Chile
 039h (57)	Columbia
 03Ah (58)	Venezuela
 03Ch (60)	Malaysia
 03Dh (61)	International English / Australia
 03Eh (62)	Indonesia / East Timor
 03Fh (63)	Philippines
 040h (64)	New Zealand
 041h (65)	Singapore
 042h (66)	Thailand (or Taiwan???)
 051h (81)	Japan (DR DOS 5.0, MS-DOS 5.0+)
 052h (82)	South Korea (DR DOS 5.0)
 054h (84)	Vietnam
 056h (86)	China (MS-DOS 5.0+)
 058h (88)	Taiwan (MS-DOS 5.0+)
 05Ah (90)	Turkey (MS-DOS 5.0+)
 05Bh (91)	India
 05Ch (92)	Pakistan
 05Dh (93)	Afghanistan
 05Eh (94)	Sri Lanka
 062h (98)	Iran
 063h (99)	Asia (English)
 066h (102)	??? (Hebrew MS-DOS 5.0)
 070h (112)	Belarus
 0C8h (200)	Thailand (PC DOS 6.1+)
		(reported as 01h due to a bug in PC DOS COUNTRY.SYS)
 0D4h (212)	Morocco
 0D5h (213)	Algeria
 0D8h (216)	Tunisia
 0DAh (218)	Libya
 0DCh (220)	Gambia
 0DDh (221)	Senegal
 0DEh (222)	Maruitania
 0DFh (223)	Mali
 0E0h (224)	African Guinea
 0E1h (225)	Ivory Coast
 0E2h (226)	Burkina Faso
 0E3h (227)	Niger
 0E4h (228)	Togo
 0E5h (229)	Benin
 0E6h (230)	Mauritius
 0E7h (231)	Liberia
 0E8h (232)	Sierra Leone
 0E9h (233)	Ghana
 0EAh (234)	Nigeria
 0EBh (235)	Chad
 0ECh (236)	Centra African Republic
 0EDh (237)	Cameroon
 0EEh (238)	Cape Verde Islands
 0EFh (239)	Sao Tome and Principe
 0F0h (240)	Equatorial Guinea
 0F1h (241)	Gabon
 0F2h (242)	Congo
 0F3h (243)	Zaire
 0F4h (244)	Angola
 0F5h (245)	Guinea-Bissau
 0F6h (246)	Diego Garcia
 0F7h (247)	Ascension Isle
 0F8h (248)	Seychelles
 0F9h (249)	Sudan
 0FAh (250)	Rwhanda
 0FBh (251)	Ethiopia
 0FCh (252)	Somalia
 0FDh (253)	Djibouti
 0FEh (254)	Kenya
 0FFh (255)	Tanzania
 100h (256)	Uganda
 101h (257)	Burundi
 103h (259)	Mozambique
 104h (260)	Zambia
 105h (261)	Madagascar
 106h (262)	Reunion Island
 107h (263)	Zimbabwe
 108h (264)	Namibia
 109h (265)	Malawi
 10Ah (266)	Lesotho
 10Bh (267)	Botswana
 10Ch (268)	Swaziland
 10Dh (269)	Comoros
 10Eh (270)	Mayotte
 122h (290)	St. Helena
 129h (297)	Aruba
 12Ah (298)	Faroe Islands
 12Bh (299)	Greenland
 15Eh (350)	Gibraltar
 15Fh (351)	Portugal
 160h (352)	Luxembourg
 161h (353)	Ireland
 162h (354)	Iceland
 163h (355)	Albania
 164h (356)	Malta
 165h (357)	Cyprus
 166h (358)	Finland
 167h (359)	Bulgaria
 172h (370)	Lithuania (reported as 372 due to a bug in MS-DOS COUNTRY.SYS)
 173h (371)	Latvia (reported as 372 due to a bug in MS-DOS COUNTRY.SYS)
 174h (372)	Estonia
 175h (373)	Moldova
 177h (375)	??? (MS-DOS 7.10 / Windows98)
 17Ch (380)	Ukraine
 17Dh (381)	Serbia / Montenegro
 180h (384)	Croatia
 181h (385)	Croatia (PC DOS 7+)
 182h (386)	Slovenia
 183h (387)	Bosnia-Herzegovina (Latin)
 184h (388)	Bosnia-Herzegovina (Cyrillic) (PC DOS 7+)
		(reported as 381 due to a bug in PC DOS COUNTRY.SYS)
 185h (389)	FYR Macedonia
 1A5h (421)	Czech Republic / Tjekia (PC DOS 7+)
 1A6h (422)	Slovakia
		(reported as 421 due to a bug in COUNTRY.SYS)
 1F4h (500)	Falkland Islands
 1F5h (501)	Belize
 1F6h (502)	Guatemala
 1F7h (503)	El Salvador
 1F8h (504)	Honduras
 1F9h (505)	Nicraragua
 1FAh (506)	Costa Rica
 1FBh (507)	Panama
 1FCh (508)	St. Pierre and Miquelon
 1FDh (509)	Haiti
 24Eh (590)	Guadeloupe
 24Fh (591)	Bolivia
 250h (592)	Guyana
 251h (593)	Ecuador
 252h (594)	rench Guiana
 253h (595)	Paraguay
 254h (596)	Martinique / French Antilles
 255h (597)	Suriname
 256h (598)	Uruguay
 257h (599)	Netherland Antilles
 29Ah (666)	Russia??? (PTS-DOS 6.51 KEYB)
 29Bh (667)	Poland??? (PTS-DOS 6.51 KEYB)
 29Ch (668)	Poland??? (Slavic???) (PTS-DOS 6.51 KEYB)
 29Eh (670)	Saipan / N. Mariana Island
 29Fh (671)	Guam
 2A0h (672)	Norfolk Island (Australia) / Christmas Island/Cocos Islands / Antartica
 2A1h (673)	Brunei Darussalam
 2A2h (674)	Nauru
 2A3h (675)	Papua New Guinea
 2A4h (676)	Tonga Islands
 2A5h (677)	Solomon Islands
 2A6h (678)	Vanuatu
 2A7h (679)	Fiji
 2A8h (680)	Palau
 2A9h (681)	Wallis & Futuna
 2AAh (682)	Cook Islands
 2ABh (683)	Niue
 2ACh (684)	American Samoa
 2ADh (685)	Western Samoa
 2AEh (686)	Kiribati
 2AFh (687)	New Caledonia
 2B0h (688)	Tuvalu
 2B1h (689)	French Polynesia
 2B2h (690)	Tokealu
 2B3h (691)	Micronesia
 2B4h (692)	Marshall Islands
 2C7h (711)	??? (currency = EA$, code pages 437,737,850,852,855,857)
 311h (785)	Arabic (Middle East/Saudi Arabia/etc.)
 324h (804)	Ukraine
 329h (809)	Antigua and Barbuda / Anguilla / Bahamas / Barbados / Bermuda
		British Virgin Islands / Cayman Islands / Dominica
		Dominican Republic / Grenada / Jamaica / Montserra
		St. Kitts and Nevis / St. Lucia / St. Vincent and Grenadines
		Trinidad and Tobago / Turks and Caicos
 352h (850)	North Korea
 354h (852)	Hong Kong
 355h (853)	Macao
 357h (855)	Cambodia
 358h (856)	Laos
 370h (880)	Bangladesh
 376h (886)	Taiwan (MS-DOS 6.22+)
 3C0h (960)	Maldives
 3C1h (961)	Lebanon
 3C2h (962)	Jordan
 3C3h (963)	Syria / Syrian Arab Republic
 3C4h (964)	Iraq
 3C5h (965)	Kuwait
 3C6h (966)	Saudi Arabia
 3C7h (967)	Yemen
 3C8h (968)	Oman
 3C9h (969)	Yemen??? (Arabic MS-DOS 5.0)
 3CBh (971)	United Arab Emirates
 3CCh (972)	Israel (Hebrew) (DR DOS 5.0,MS-DOS 5.0+)
 3CDh (973)	Bahrain
 3CEh (974)	Qatar
 3CFh (975)	Bhutan
 3D0h (976)	Mongolia
 3D1h (977)	Nepal
 3E3h (995)	Myanmar (Burma)
      (10xxx)	reserved for ISO 28601/ISO 8601 or derivative national stds
      (11xxx)	reserved for Euro currency support
      (12xxx)	reserved for ISO 28601 + Euro currency
      (1xxxx)	not yet defined
      (20xxx)	reserved for ISO 28601/ISO 8601 or derivative national stds
      (21xxx)	reserved for Euro currency support
      (22xxx)	reserved for ISO 28601 + Euro currency
      (2xxxx)	not yet defined
      (30xxx)	reserved for user-definable country codes
      (31xxx)	reserved for OEM-defined country codes
      (32000+)	reserved for future expansion
Note:	not all country codes are supported by all versions of DOS

INT 21 - DOS 3.0+ - SET COUNTRY CODE
	AH = 38h
	DX = FFFFh
	AL = 01h thru FEh for specific country with code <255
	AL = FFh for specific country with code >= 255
	   BX = 16-bit country code (see #01400)
Return: CF set on error
	    AX = error code (see #01680 at AH=59h/BX=0000h)
	CF clear if successful
Note:	not supported by OS/2
SeeAlso: INT 2F/AX=1403h

INT 21 - DOS 2+ - "MKDIR" - CREATE SUBDIRECTORY
	AH = 39h
	DS:DX -> ASCIZ pathname
Return: CF clear if successful
	    AX destroyed
	CF set on error
	    AX = error code (03h,05h) (see #01680 at AH=59h/BX=0000h)
Notes:	all directories in the given path except the last must exist
	fails if the parent directory is the root and is full
	DOS 2.x-3.3 allow the creation of a directory sufficiently deep that
	  it is not possible to make that directory the current directory
	  because the path would exceed 64 characters
	under the FlashTek X-32 DOS extender, the pointer is in DS:EDX
SeeAlso: AH=3Ah,AH=3Bh,AH=6Dh,AX=7139h,AH=E2h/SF=0Ah,AX=43FFh/BP=5053h
SeeAlso: INT 2F/AX=1103h,INT 60/DI=0511h

INT 21 - DOS 2+ - "RMDIR" - REMOVE SUBDIRECTORY
	AH = 3Ah
	DS:DX -> ASCIZ pathname of directory to be removed
Return: CF clear if successful
	    AX destroyed
	CF set on error
	    AX = error code (03h,05h,06h,10h) (see #01680 at AH=59h/BX=0000h)
Notes:	directory must be empty (contain only '.' and '..' entries)
	under the FlashTek X-32 DOS extender, the pointer is in DS:EDX
SeeAlso: AH=39h,AH=3Bh,AX=713Ah,AH=E2h/SF=0Bh,INT 2F/AX=1101h,INT 60/DI=0512h

INT 21 - DOS 2+ - "CHDIR" - SET CURRENT DIRECTORY
	AH = 3Bh
	DS:DX -> ASCIZ pathname to become current directory (max 64 bytes)
Return: CF clear if successful
	    AX destroyed
	CF set on error
	    AX = error code (03h) (see #01680 at AH=59h/BX=0000h)
Notes:	if new directory name includes a drive letter, the default drive is
	  not changed, only the current directory on that drive
	changing the current directory also changes the directory in which
	  FCB file calls operate
	under the FlashTek X-32 DOS extender, the pointer is in DS:EDX
SeeAlso: AH=47h,AX=713Bh,INT 2F/AX=1105h

INT 21 - DOS 2+ - "CREAT" - CREATE OR TRUNCATE FILE
	AH = 3Ch
	CX = file attributes (see #01401)
	DS:DX -> ASCIZ filename
Return: CF clear if successful
	    AX = file handle
	CF set on error
	    AX = error code (03h,04h,05h) (see #01680 at AH=59h/BX=0000h)
Notes:	if a file with the given name exists, it is truncated to zero length
	under the FlashTek X-32 DOS extender, the pointer is in DS:EDX
	DR DOS checks the system password or explicitly supplied password at
	  the end of the filename against the reserved field in the directory
	  entry before allowing access
SeeAlso: AH=16h,AH=3Dh,AH=5Ah,AH=5Bh,AH=93h,INT 2F/AX=1117h

Bitfields for file attributes:
Bit(s)	Description	(Table 01401)
 0	read-only
 1	hidden
 2	system
 3	volume label (ignored)
 4	reserved, must be zero (directory)
 5	archive bit
 7	if set, file is shareable under Novell NetWare

INT 21 - DOS 2+ - "OPEN" - OPEN EXISTING FILE
	AH = 3Dh
	AL = access and sharing modes (see #01402)
	DS:DX -> ASCIZ filename
	CL = attribute mask of files to look for (server call only)
Return: CF clear if successful
	    AX = file handle
	CF set on error
	    AX = error code (01h,02h,03h,04h,05h,0Ch,56h) (see #01680 at AH=59h)
Notes:	file pointer is set to start of file
	if SHARE or a network is loaded, the file open may fail if the file
	  is already open, depending on the combination of sharing modes
	  (see #01403,#01404)
	file handles which are inherited from a parent also inherit sharing
	  and access restrictions
	files may be opened even if given the hidden or system attributes
	under the FlashTek X-32 DOS extender, the pointer is in DS:EDX
	DR DOS checks the system password or explicitly supplied password at
	  the end of the filename (following a semicolon) against the reserved
	  field in the directory entry before allowing access
	sharing modes are only effective on local drives if SHARE is loaded
BUG:	Novell DOS 7 SHARE v1.00 would refuse file access in the cases in
	  #01403 marked with [1] (read-only open of a read-only file
	  which had previously been opened in compatibility mode); this was
	  fixed in SHARE v1.01 of 09/29/94
SeeAlso: AH=0Fh,AH=3Ch,AX=4301h,AX=5D00h,INT 2F/AX=1116h,INT 2F/AX=1226h

Bitfields for access and sharing modes:
Bit(s)	Description	(Table 01402)
 2-0	access mode
	000 read only
	001 write only
	010 read/write
	011 (DOS 5+ internal) passed to redirector on EXEC to allow
		case-sensitive filenames
 3	reserved (0)
 6-4	sharing mode (DOS 3.0+) (see #01403)
	000 compatibility mode
	001 "DENYALL" prohibit both read and write access by others
	010 "DENYWRITE" prohibit write access by others
	011 "DENYREAD" prohibit read access by others
	100 "DENYNONE" allow full access by others
	111 network FCB (only available during server call)
 7	inheritance
	if set, file is private to current process and will not be inherited
	  by child processes
SeeAlso: #01782,#01403

(Table 01403)
Values of DOS 2-6.22 file sharing behavior:
	  |	Second and subsequent Opens
 First	  |Compat  Deny	  Deny	 Deny	Deny
 Open	  |	   All	  Write	 Read	None
	  |R W RW R W RW R W RW R W RW R W RW
 - - - - -| - - - - - - - - - - - - - - - - -
 Compat R |Y Y Y  N N N	 1 N N	N N N  1 N N
	W |Y Y Y  N N N	 N N N	N N N  N N N
	RW|Y Y Y  N N N	 N N N	N N N  N N N
 - - - - -|
 Deny	R |C C C  N N N	 N N N	N N N  N N N
 All	W |C C C  N N N	 N N N	N N N  N N N
	RW|C C C  N N N	 N N N	N N N  N N N
 - - - - -|
 Deny	R |2 C C  N N N	 Y N N	N N N  Y N N
 Write	W |C C C  N N N	 N N N	Y N N  Y N N
	RW|C C C  N N N	 N N N	N N N  Y N N
 - - - - -|
 Deny	R |C C C  N N N	 N Y N	N N N  N Y N
 Read	W |C C C  N N N	 N N N	N Y N  N Y N
	RW|C C C  N N N	 N N N	N N N  N Y N
 - - - - -|
 Deny	R |2 C C  N N N	 Y Y Y	N N N  Y Y Y
 None	W |C C C  N N N	 N N N	Y Y Y  Y Y Y
	RW|C C C  N N N	 N N N	N N N  Y Y Y
Legend: Y = open succeeds, N = open fails with error code 05h
	C = open fails, INT 24 generated
	1 = open succeeds if file read-only, else fails with error code
	2 = open succeeds if file read-only, else fails with INT 24
SeeAlso: #01636,#01404

(Table 01404)
Values for DOS 7.x file sharing behavior:
	  |	Second and subsequent Opens
 First	  |Compat    Deny      Deny	 Deny	   Deny
 Open	  |	     All       Write	 Read	   None
	  |R W RW A  R W RW A  R W RW A	 R W RW A  R W RW A
 - - - - -| - - - - - - - - - - - - - - - - - - - - - - - -
 Compat R |Y Y Y Y   N N N N   Y N N Y	 N N N Y   Y N N Y
	W |Y Y Y C   N N N N   N N N N	 N N N Y   Y N N Y
	RW|Y Y Y C   N N N N   N N N N	 N N N Y   Y N N Y
	NA|Y C C Y   N N N N   Y N N Y	 N N N Y   Y N N Y
 - - - - -|
 Deny	R |C C C C   N N N N   N N N N	 N N N N   N N N N
 All	W |C C C C   N N N N   N N N N	 N N N N   N N N N
	RW|C C C C   N N N N   N N N N	 N N N N   N N N N
	NA|C C C C   N N N N   N N N N	 N N N N   N N N N
 - - - - -|
 Deny	R |Y C C Y   N N N N   Y N N Y	 N N N Y   Y N N Y
 Write	W |C C C C   N N N N   N N N N	 Y N N Y   Y N N Y
	RW|C C C C   N N N N   N N N N	 N N N Y   Y N N Y
	NA|Y C C Y   N N N N   Y N N Y	 N N N Y   Y N N Y
 - - - - -|
 Deny	R |C C C C   N N N N   N Y N N	 N N N N   N Y N N
 Read	W |C C C C   N N N N   N N N N	 N Y N N   N Y N N
	RW|C C C C   N N N N   N N N N	 N N N N   N Y N N
	NA|Y Y Y Y   N N N N   Y Y Y Y	 N N N Y   Y Y Y Y
 - - - - -|
 Deny	R |Y Y Y Y   N N N N   Y Y Y Y	 N N N Y   Y Y Y Y
 None	W |C C C C   N N N N   N N N N	 Y Y Y Y   Y Y Y Y
	RW|C C C C   N N N N   N N N N	 N N N Y   Y Y Y Y
	NA|Y Y Y Y   N N N N   Y Y Y Y	 N N N Y   Y Y Y Y
Legend: R -> reading, W -> writing, RW -> both reading & writing,
	A/NA -> reading without access time update
	Y = open succeeds, N = open fails with error code 05h
	C = open fails, INT 24 generated
SeeAlso: #01403,#01636

INT 21 - VIRUS - "GT-SPOOF" -INSTALLATION CHECK
	AX = 3D76h
Return: AX = 763Dh if resident
SeeAlso: AX=357Fh,AX=3DFFh

INT 21 - VIRUS - "JD-448" - INSTALLATION CHECK
	AX = 3DFFh
Return: AX = 4A44h if resident
SeeAlso: AX=3D76h,AX=4203h

INT 21 - DOS 2+ - "CLOSE" - CLOSE FILE
	AH = 3Eh
	BX = file handle
Return: CF clear if successful
	    AX destroyed
	CF set on error
	    AX = error code (06h) (see #01680 at AH=59h/BX=0000h)
Notes:	if the file was written to, any pending disk writes are performed, the
	  time and date stamps are set to the current time, and the directory
	  entry is updated
	recent versions of DOS preserve AH because some versions of Multiplan
	  had a bug which depended on AH being preserved
SeeAlso: AH=10h,AH=3Ch,AH=3Dh,INT 2F/AX=1106h,INT 2F/AX=1227h

INT 21 - DOS 2+ - "READ" - READ FROM FILE OR DEVICE
	AH = 3Fh
	BX = file handle
	CX = number of bytes to read
	DS:DX -> buffer for data
Return: CF clear if successful
	    AX = number of bytes actually read (0 if at EOF before call)
	CF set on error
	    AX = error code (05h,06h) (see #01680 at AH=59h/BX=0000h)
Notes:	data is read beginning at current file position, and the file position
	  is updated after a successful read
	the returned AX may be smaller than the request in CX if a partial
	  read occurred
	if reading from CON, read stops at first CR
	under the FlashTek X-32 DOS extender, the pointer is in DS:EDX
BUG:	Novell NETX.EXE v3.26 and 3.31 do not set CF if the read fails due to
	  a record lock (see AH=5Ch), though it does return AX=0005h; this
	  has been documented by Novell
SeeAlso: AH=27h,AH=40h,AH=93h,INT 2F/AX=1108h,INT 2F/AX=1229h

INT 21 - Turbo Debug HARDWARE BREAKPOINTS - READ STATUS BLOCK
	AH = 3Fh
	BX = handle for character device "TDHDEBUG"
	CX = number of bytes to read
	DS:DX -> buffer for status block (see #01406)
Return: CF clear if successful
	    AX = number of bytes actually read
	CF set on error
	    AX = error code (05h,06h) (see #01680 at AH=59h/BX=0000h)
SeeAlso: AH=40h"Turbo Debug"

(Table 01405)
Values for status of Turbo Debugger command:
 00h	successful
 01h	invalid handle
 02h	no more breakpoints available
 03h	hardware does not support specified breakpoint type
 04h	previous command prevents execution
 05h	debugger hardware not found
 06h	hardware failure
 07h	invalid command
 08h	driver not initialized yet
 FEh	recursive entry (hardware breakpoint inside hw bp handler)

Format of Turbo Debugger status block:
Offset	Size	Description	(Table 01406)
 00h	BYTE	status of command (see #01405)
---status for command 01h---
 01h	WORD	device driver interface version number (currently 1)
 03h	WORD	device driver software version
 05h	BYTE	maximum simultaneous hardware breakpoints
 06h	BYTE	configuration bits (see #01407)
 07h	BYTE	supported breakpoint types (see #01408)
 08h	WORD	supported addressing match modes (see #01409)
 0Ah	WORD	supported data matches (see #01410)
 0Ch	BYTE	maximum data match length (01h, 02h, or 04h)
 0Dh	WORD	size of onboard memory (in KB)
 0Fh	WORD	maximum number of trace-back events
 11h	WORD	hardware breakpoint enable byte address segment (0000h if not
		  supported)
---status for command 04h---
 01h	BYTE	handle to use when referring to the just-set breakpoint

Bitfields for Turbo Debugger configuration bits:
Bit(s)	Description	(Table 01407)
 0	CPU and DMA accesses are distinct
 1	can detect DMA transfers
 2	supports data mask
 3	hardware pass counter on breakpoints
 4	can match on data as well as addresses

Bitfields for Turbo Debugger supported breakpoint types:
Bit(s)	Description	(Table 01408)
 0	memory read
 1	memory write
 2	memory read/write
 3	I/O read
 4	I/O write
 5	I/O read/write
 6	instruction fetch

Bitfields for Turbo Debugger supported addressing match modes:
Bit(s)	Description	(Table 01409)
 0	any address
 1	equal to test value
 2	not equal
 3	above test value
 4	below test value
 5	below or equal
 6	above or equal
 7	within range
 8	outside range

Bitfields for Turbo Debugger supported data matches:
Bit(s)	Description	(Table 01410)
 0	any data
 1	equal to test value
 2	not equal
 3	above test value
 4	below test value
 5	below or equal
 6	above or equal
 7	within range
 8	outside range

INT 21 - PC/TCP IPCUST.SYS - READ CONFIGURATION DATA
	AH = 3Fh
	BX = handle for character device "$IPCUST"
	CX = number of bytes to read
	DS:DX -> buffer for configuration data (see #01411)
Return: CF clear if successful
	    AX = number of bytes actually read
	CF set on error
	    AX = error code (05h,06h) (see #01680 at AH=59h/BX=0000h)
Notes:	if less than the entire data is read or written, the next read/write
	  continues where the previous one ended; IOCTL calls AX=4402h and
	  AX=4403h both reset the location at which the next operation starts
	  to zero
	the data pointer is also reset to zero if the previous read or write
	  reached or exceeded the end of the data, when the current function
	  is read and the previous was write, or vice versa
	v2.1+ uses a new configuration method, but allows the installation
	  of IPCUST.SYS for backward compatibility with other software which
	  must read the PC/TCP configuration
SeeAlso: AH=40h"IPCUST",AX=4402h"IPCUST",AX=4402h"FTPSOFT"

Format of PC/TCP configuration data:
Offset	Size	Description	(Table 01411)
 00h 12 BYTEs	IPCUST.SYS device driver header (see #01646)
 12h	BYTE	???
 13h	BYTE	???
 14h	WORD	???
 16h	BYTE	bit flags
		bit 0: send BS rather than DEL for BackSpace key
		bit 1: wrap long lines
 17h	BYTE	???
 18h 64 BYTEs	ASCIZ hostname
 58h 64 BYTEs	ASCIZ domain name
		(fully qualified domain name is hostname.domain-name)
 98h 16 BYTEs	ASCIZ username
 A8h 64 BYTEs	ASCIZ full name
 E8h 64 BYTEs	ASCIZ office address
128h 32 BYTEs	ASCIZ phone number
148h	WORD	offset from GMT in minutes
14Ah  4 BYTEs	ASCIZ timezone name
14Eh	WORD	number of time servers
150h  ? DWORDs	(big-endian) IP addresses for time servers
	???
164h	WORD	number of old-style name servers
166h  3 DWORDs	(big-endian) IP addresses for name servers
172h	WORD	number of domain name servers
174h  3 DWORDs	(big-endian) IP addresses for domain name servers
180h	DWORD	(big-endian) IP address of default gateway
184h	DWORD	(big-endian) IP address of log server
188h	DWORD	(big-endian) IP address of cookie server
18Ch	DWORD	(big-endian) IP address of lpr server
190h	DWORD	(big-endian) IP address of imagen print server
194h 54 BYTEs	???
1E8h	WORD	TCP default window size in bytes
1EAh	WORD	TCP low window size
1ECh 64 BYTEs	ASCIZ host tabel filename
22Ch  2 BYTEs	???
22Eh 80 BYTEs	ASCIZ mail relay host name
27Eh	BYTE	???
27Fh	BYTE	??? bit flags
280h 44 BYTEs	???
2ACh	WORD	???
2AEh 202 BYTEs	???

INT 21 - WORKGRP.SYS - GET ENTRY POINT
	AH = 3Fh
	BX = file handle for device "NET$HLP$"
	CX = 0008h
	DS:DX -> buffer for entry point record (see #01485)
Return: CF clear if successful
	    AX = number of bytes actually read (0 if at EOF before call)
	CF set on error
	    AX = error code (05h,06h) (see #01680 at AH=59h/BX=0000h)
Program: WORKGRP.SYS is the portion of Microsoft's Workgroup Connection which
	  permits communication with PCs running Windows for Workgroups or
	  LAN Manager
SeeAlso: AX=4402h"WORKGRP.SYS",INT 2F/AX=9400h

INT 21 - BW-TCP - GET DRIVER INFO
	AH = 3Fh
	BX = file handle for device "ETHDEV27"
	CX = 002Bh
	DS:DX -> buffer for driver info (see #01412)
Return: CF clear if successful
	    AX = number of bytes actually read (0 if at EOF before call)
	CF set on error
	    AX = error code (05h,06h) (see #01680 at AH=59h/BX=0000h)
Program: BW-TCP is a TCP/IP protocol stack by Beame & Whiteside Software
InstallCheck:	for the TCP/IP stack, test for the existence of the character
	  device UDP-IP10
Note:	the B&W socket library performs an INT 21/AX=4401h with DX=0060h before
	  making this call to retrieve the driver information; one should also
	  call the private API interrupt with AH=15h
SeeAlso: INT 14/AH=56h,INT 62/AH=00h"ETHDEV",INT 63/AH=03h,INT 64/AH=01h
Index:	installation check;BW-TCP hardware driver
Index:	installation check;BW-TCP TCPIP.SYS

Format of BW-TCP driver info:
Offset	Size	Description	(Table 01412)
 00h	WORD	I/O base address
 02h	BYTE	shared memory page (01h = segment 0100h, etc.)
 03h	BYTE	interrupt vector for private API
 04h	BYTE	IRQ used by board
 05h	WORD	size of data buffer
 07h	WORD	maximum transfer window
 09h	WORD	time zone
 0Bh	BYTE	address type (01h user, 04h RARP, 05h BOOTP)
 0Ch	DWORD	internet address
 10h	WORD	"value" ???
 12h	BYTE	subnet mask
 13h	WORD	"ether_pointer" ???
 15h	WORD	offset in device driver of log server records (see #01413)
 17h	WORD	offset in device driver of name server records (see #01413)
 19h	WORD	offset in device driver of print server records (see #01413)
 1Bh	WORD	offset in device driver of time server records (see #01413)
 1Dh	WORD	offset in device driver of gateway records (see #01413)
 1Fh	WORD	segment address of device driver
 21h	BYTE	transfer size
 22h  9 BYTEs	network adapter board name
---11/21/91+ ---
 23h	BYTE	ETHDEV version (major in high nybble, minor in low nybble)
 24h	BYTE	ETHDEV revision
 25h	BYTE	TCPIP version (major in high nybble, minor in low nybble)
 26h	BYTE	TCPIP revision
 27h	BYTE	BWRPC version (major in high nybble, minor in low nybble)
 28h	BYTE	BWRPC revision
 29h	BYTE	BWNFS version (major in high nybble, minor in low nybble)
 2Ah	BYTE	BWNFS revision
 2Bh	BYTE	Telnet version (major in high nybble, minor in low nybble)
 2Ch	BYTE	Telnet revision
 2Dh	BYTE	NETBIOS version (major in high nybble, minor in low nybble)
 2Eh	BYTE	NETBIOS revision
Note:	for each driver, if version=0, the driver is not installed or does
	  not support the version check

Format of BW-TCP server records:
Offset	Size	Description	(Table 01413)
 00h	BYTE	number of server records following
 01h  N DWORDs	internet addresses of servers

INT 21 - Trusted Access - NB.SYS - GET STATE
	AH = 3Fh
	BX = file handle for device "$$NB$$NB"
	CX = 0002h (size of state)
	DS:DX -> buffer for state record (see #01414)
Return: CF clear if successful
	    AX = number of bytes actually read (0 if at EOF before call)
	CF set on error
	    AX = error code (05h,06h) (see #01680 at AH=59h/BX=0000h)
Program: Trusted Access is a security and access-control package by Lassen
	  Software, Inc.; NB.SYS is a device driver to prevent the user from
	  terminating CONFIG.SYS or AUTOEXEC.BAT with Ctrl-Break
SeeAlso: AH=40h"NB.SYS",AX=4101h

Format of Trusted Access state record:
Offset	Size	Description	(Table 01414)
 00h	BYTE	00h off, 01h on
 01h	BYTE	keys being disabled
		bit 0: Ctrl-Break
		bit 1: SysReq
		bit 2: Ctrl and Alt
		bit 3: Ctrl-Alt-Del
		bit 7: all keys (overrides other bits)

INT 21 U - IFSHLP.SYS - GET ENTRY POINT
	AH = 3Fh
	BX = file handle for device "IFS$HLP$"
	CX = 0008h (size of buffer in bytes)
	DS:DX -> buffer for entry point record (see #01415)
Return: CF clear if successful
	    AX = number of bytes actually read (0 if at EOF before call)
	CF set on error
	    AX = error code (05h,06h) (see #01680 at AH=59h/BX=0000h)
Program: IFSHLP.SYS is a support driver for Microsoft Windows for Workgroups
SeeAlso: AX=4402h"IFSHLP"

Format of IFSHLP.SYS entry point record:
Offset	Size	Description	(Table 01415)
 00h  4 BYTEs	(call) required signature if called via IOCTL
			70h E9h 34h 37h for Windows 3.11
			70h E9h 35h 37h for Windows 3.11
		(ret) signature 34h 37h 70h EFh (Windows 3.11)
		(ret) signature 35h 37h 70h EFh (Windows95)
 04h	DWORD	(ret) pointer to FAR call entry point (see #01416)

(Table 01416)
Call IFSHLP.SYS entry point with:
	STACK:	WORD	function number (00h-0Ch)
			00h get ??? data
			01h set interrupt intercepts (trap)
			02h remove interrupt intercepts (untrap)
			03h ??? LPT2
			04h ??? LPT1
			05h revector INT 2F to trap and remove trap for others
			06h set ??? flag
			07h clear ??? flag
			08h get ??? flag word
			---Windows 3.11 only---
			09h ???
			0Ah ???
			0Bh ???
			0Ch get ???
---if function 00h---
Return: DX:AX -> ??? data (see #01417)
	BX destroyed
---if function 01h---
	STACK:	DWORD	new intercept (trap) address
Return: AX = status
	    0000h successful
	    0001h failed (already set)
		DX = 0000h
	BX destroyed
Note:	the trap handler is called with a function number in BX, and the
	  original BX on top of the stack; a null handler must perform a
	  POP BX and an IRET
---if function 02h---
Return: AX = status
	    0000h successful
	    0001h failed (not set)
	DX = 0000h
	BX destroyed
---if function 03h,04h---
	STACK:	WORD	???
Return: AX = 0000h
	DX = 0000h
	BX destroyed
---if function 05h---
	???
Return:	BX destroyed
---if function 06h---
Return: AX = 0001h and DX = 0000h if already set
	AX,DX unchanged if successful
	BX destroyed
---if function 07h---
Return: AX = 0001h and DX = 0000h if not set
	AX,DX unchanged if successful
	BX destroyed
---if function 08h---
Return: DX = 0000h
	AX = flags
	    bit 0: set/cleared by functions 06h and 07h
	    bit 1: trap is currently set (refer to functions 01h/02h)
	BX destroyed
---if function 09h---
Return: AX = status
	    0000h successful
	    0001h failed (already called)
	BX destroyed
---if function 0Ah---
	STACK:	WORD	???
	???
Return:	BX destroyed
---if function 0Bh---
Return: AX = status
	    0000h successful
	    0001h failed (not set)
	BX destroyed
---if function 0Ch---
Return: AX = 0000h
	ES:BX -> ??? data
---if function > 0Ch---
Return: AX = 0001h
	DX = 0000h
	BX destroyed

Format of IFSHLP ??? data:
Offset	Size	Description	(Table 01417)
 00h	DWORD	-> DOS Swappable Data Area (see #01687,#01689)
 02h	WORD	??? offset in DOS data segment?
 04h	WORD	offset in DOS data segment of current-PSP WORD
 06h	WORD	???
 08h	WORD	???
 0Ah	WORD	???
 0Ch	DWORD	-> DOS List of Lists (see #01627)
 10h	???
SeeAlso: #01416

INT 21 - VIRUS - "KYZ/LieWait" - INSTALLATION CHECK
	AH = 3Fh
	BX = FEB0h
Return: BX = 1212h if resident
SeeAlso: AX=3032h"VIRUS",AX=4BF1h"VIRUS"

INT 21 - DOS 2+ - "WRITE" - WRITE TO FILE OR DEVICE
	AH = 40h
	BX = file handle
	CX = number of bytes to write
	DS:DX -> data to write
Return: CF clear if successful
	    AX = number of bytes actually written
	CF set on error
	    AX = error code (05h,06h) (see #01680 at AH=59h/BX=0000h)
Notes:	if CX is zero, no data is written, and the file is truncated or
	  extended to the current position
	data is written beginning at the current file position, and the file
	  position is updated after a successful write
	for FAT32 drives, the file must have been opened with AX=6C00h with
	  the "extended size" flag in order to expand the file beyond 2GB;
	  otherwise the write will fail with error code 0005h (access denied)
	the usual cause for AX < CX on return is a full disk
BUG:	a write of zero bytes will appear to succeed when it actually failed
	  if the write is extending the file and there is not enough disk
	  space for the expanded file (DOS 5.0-6.0); one should therefore check
	  whether the file was in fact extended by seeking to 0 bytes from
	  the end of the file (INT 21/AX=4202h/CX=0000h/DX=0000h)
	under the FlashTek X-32 DOS extender, the pointer is in DS:EDX
SeeAlso: AH=28h,AH=3Fh"DOS",AH=93h,INT 2F/AX=1109h

INT 21 - Turbo Debug HARDWARE BREAKPOINTS - SEND CMD TO HARDWARE BRKPNT DRIVER
	AH = 40h
	BX = handle for character device "TDHDEBUG"
	CX = number of bytes to write
	DS:DX -> hardware breakpoint command (see #01418)
Return: CF clear if successful
	    AX = number of bytes actually written
	CF set on error
	    AX = error code (05h,06h) (see #01680 at AH=59h/BX=0000h)
Note:	results are retrieved by reading from the device
SeeAlso: AH=3Fh"Turbo Debug"

Format of Turbo Debugger hardware breakpoint commands:
Offset	Size	Description	(Table 01418)
 00h	BYTE	command code
		00h install interrupt vectors
		01h get hardware capabilities
		02h enable hardware breakpoints
		03h disable hardware breakpoints
		04h set hardware breakpoint
		05h clear hardware breakpoint
		06h set I/O base address and reset hardware
		07h restore interrupt vectors
---command code 00h---
 01h	DWORD	pointer to Turbo Debugger entry point to be jumped to on
		  hardware breakpoint; call with CPU state the same as on
		  the breakpoint except for pushing AX and placing an entry
		  code (FFh if breakout button or breakpoint handle) in AH
---command code 04h---
 01h	BYTE	breakpoint type
		00h memory read
		01h memory write
		02h memory read/write
		03h I/O read
		04h I/O write
		05h I/O read/write
		06h instruction fetch
 02h	BYTE	address matching mode (see #01419)
 03h	DWORD	32-bit linear low address
 07h	DWORD	32-bit linear high address
 0Bh	WORD	pass count
 0Dh	BYTE	data size (01h, 02h, or 04h)
 0Eh	BYTE	source of matched bus cycle (01h CPU, 02h DMA, 03h either)
 0Fh	BYTE	data-matching mode (see #01419)
 10h	DWORD	low data value
 14h	DWORD	high data value
 18h	DWORD	data mask specifying which bits of the data are tested
---command code 05h---
 01h	BYTE	handle of breakpoint to clear (breakpoint returned from command
		  04h)
---command code 06h---
 01h	WORD	base address of hardware debugger board

(Table 01419)
Values for Turbo Debugger address/data matching mode:
 00h	match any
 01h	equal to test value
 02h	different from test value
 03h	above test value
 04h	below test value
 05h	below or equal to test value
 06h	above or equal to test value
 07h	within inclusive range
 08h	outside specified range

INT 21 - PC/TCP IPCUST.SYS - WRITE CONFIGURATION DATA
	AH = 40h
	BX = handle for character device "$IPCUST"
	CX = number of bytes to write
	DS:DX -> buffer for configuration data (AH=3Fh"IPCUST")
Return: CF clear if successful
	    AX = number of bytes actually written
	CF set on error
	    AX = error code (05h,06h) (see #01680 at AH=59h/BX=0000h)
Notes:	if less than the entire data is read or written, the next read/write
	  continues where the previous one ended; IOCTL calls AX=4402h and
	  AX=4403h both reset the location at which the next operation starts
	  to zero
	the data pointer is also reset to zero if the previous read or write
	  reached or exceeded the end of the data, when the current function
	  is read and the previous was write, or vice versa
	v2.1+ uses a new configuration method, but allows the installation
	  of IPCUST.SYS for backward compatibility with other software which
	  must read the PC/TCP configuration
SeeAlso: AH=3Fh"IPCUST",AX=4402h"IPCUST"

INT 21 U - Trusted Access - NB.SYS - SET STATE
	AH = 40h
	BX = handle for character device "$$NB$$NB"
	DS:DX -> state record (see #01414)
	CX ignored
Return: CF clear if successful
	    AX = number of bytes actually written
	CF set on error
	    AX = error code (05h,06h) (see #01680 at AH=59h/BX=0000h)
Program: Trusted Access is a security and access-control package by Lassen
	  Software, Inc.; NB.SYS is a device driver to prevent the user from
	  terminating CONFIG.SYS or AUTOEXEC.BAT with Ctrl-Break
SeeAlso: AH=3Fh"NB.SYS"

INT 21 - FARTBELL.EXE - INSTALLATION CHECK
	AX = 4000h
	BX = 0002h
	CX = 0000h
	DS:DX = 0000h:0000h
Return: CF clear if installed
	    AX = CS of resident code
Program: FARTBELL is a joke program by Guenther Thiele which makes various
	  noises when programs output a bell
SeeAlso: AX=4001h

INT 21 - FARTBELL.EXE - FORCE NOISE
	AX = 4001h
	BX = 0002h
	CX = 0000h
	DS:DX = 0000h:0000h
Program: FARTBELL is a joke program by Guenther Thiele which makes various
	  noises when programs output a bell
SeeAlso: AX=4000h

INT 21 - DOS 2+ - "UNLINK" - DELETE FILE
	AH = 41h
	DS:DX -> ASCIZ filename (no wildcards, but see notes)
	CL = attribute mask for deletion (server call only, see notes)
Return: CF clear if successful
	    AX destroyed (DOS 3.3) AL seems to be drive of deleted file
	CF set on error
	    AX = error code (02h,03h,05h) (see #01680 at AH=59h/BX=0000h)
Notes:	(DOS 3.1+) wildcards are allowed if invoked via AX=5D00h, in which case
	  the filespec must be canonical (as returned by AH=60h), and only
	  files matching the attribute mask in CL are deleted
	DR DOS 5.0-6.0 returns error code 03h if invoked via AX=5D00h; DR DOS
	  3.41 crashes if called via AX=5D00h with wildcards
	DOS does not erase the file's data; it merely becomes inaccessible
	  because the FAT chain for the file is cleared
	deleting a file which is currently open may lead to filesystem
	  corruption.  Unless SHARE is loaded, DOS does not close the handles
	  referencing the deleted file, thus allowing writes to a nonexistant
	  file.
	under DR DOS and DR Multiuser DOS, this function will fail if the file
	  is currently open
	under the FlashTek X-32 DOS extender, the pointer is in DS:EDX
BUG:	DR DOS 3.41 crashes if called via AX=5D00h
SeeAlso: AH=13h,AX=4301h,AX=4380h,AX=5D00h,AH=60h,AX=7141h,AX=F244h
SeeAlso: INT 2F/AX=1113h

INT 21 - SoftLogic Data Guardian - ???
	AX = 4101h
	DX = FFFEh
Return: AX = 0000h if installed
Note:	resident code sets several internal variables on this call
SeeAlso: AH=3Fh"NB.SYS",INT 16/AX=FFA3h/BX=0000h

INT 21 - DOS 2+ - "LSEEK" - SET CURRENT FILE POSITION
	AH = 42h
	AL = origin of move
	    00h start of file
	    01h current file position
	    02h end of file
	BX = file handle
	CX:DX = (signed) offset from origin of new file position
Return: CF clear if successful
	    DX:AX = new file position in bytes from start of file
	CF set on error
	    AX = error code (01h,06h) (see #01680 at AH=59h/BX=0000h)
Notes:	for origins 01h and 02h, the pointer may be positioned before the
	  start of the file; no error is returned in that case (except under
	  Windows NT), but subsequent attempts at I/O will produce errors
	if the new position is beyond the current end of file, the file will
	  be extended by the next write (see AH=40h); for FAT32 drives, the
	  file must have been opened with AX=6C00h with the "extended size"
	  flag in order to expand the file beyond 2GB
BUG:	using this method to grow a file from zero bytes to a very large size
	  can corrupt the FAT in some versions of DOS; the file should first
	  be grown from zero to one byte and then to the desired large size
SeeAlso: AH=24h,INT 2F/AX=1228h

INT 21 - VIRUS - "Shake" - INSTALLATION CHECK
	AX = 4203h
Return: AX = 1234h if resident
SeeAlso: AX=3DFFh,AX=4243h

INT 21 - VIRUS - "Invader" - INSTALLATION CHECK
	AX = 4243h
Return: AX = 5678h if resident
SeeAlso: AX=4203h,AX=44A0h,AX=4B04h

INT 21 - DOS 2+ - GET FILE ATTRIBUTES
	AX = 4300h
	DS:DX -> ASCIZ filename
Return: CF clear if successful
	    CX = file attributes (see #01420)
	    AX = CX (DR DOS 5.0)
	CF set on error
	    AX = error code (01h,02h,03h,05h) (see #01680 at AH=59h)
Notes:	under the FlashTek X-32 DOS extender, the filename pointer is in DS:EDX
	under DR DOS 3.41 and 5.0, attempts to change the subdirectory bit are
	  simply ignored without an error
BUG:	Windows for Workgroups returns error code 05h (access denied) instead
	  of error code 02h (file not found) when attempting to get the
	  attributes of a nonexistent file.  This causes open() with O_CREAT
	  and fopen() with the "w" mode to fail in Borland C++.
SeeAlso: AX=4301h,AX=4310h,AX=7143h,AH=B6h,INT 2F/AX=110Fh,INT 60/DI=0517h

INT 21 - DOS 2+ - "CHMOD" - SET FILE ATTRIBUTES
	AX = 4301h
	CX = new file attributes (see #01420)
	DS:DX -> ASCIZ filename
Return: CF clear if successful
	    AX destroyed
	CF set on error
	    AX = error code (01h,02h,03h,05h) (see #01680 at AH=59h)
Notes:	will not change volume label or directory attribute bits, but will
	  change the other attribute bits of a directory (the directory
	  bit must be cleared to successfully change the other attributes of a
	  directory, but the directory will not be changed to a normal file as
	  a result)
	MS-DOS 4.01 reportedly closes the file if it is currently open
	for security reasons, the Novell NetWare execute-only bit can never
	  be cleared; the file must be deleted and recreated
	under the FlashTek X-32 DOS extender, the filename pointer is in DS:EDX
	DOS 5.0 SHARE will close the file if it is currently open in sharing-
	  compatibility mode, otherwise a sharing violation critical error is
	  generated if the file is currently open
	DR DOS 3.41/5.0 will silently ignore attempts to change the 'directory'
	  attribute bit
SeeAlso: AX=4300h,AX=4311h,AX=7143h,INT 2F/AX=110Eh

Bitfields for file attributes:
Bit(s)	Description	(Table 01420)
 7	shareable (Novell NetWare)
 7	pending deleted files (Novell DOS, OpenDOS)
 6	unused
 5	archive
 4	directory
 3	volume label
	execute-only (Novell NetWare)
 2	system
 1	hidden
 0	read-only

INT 21 - MS-DOS 7 - GET COMPRESSED FILE SIZE
	AX = 4302h
	DS:DX -> ASCIZ pathname for file or directory
Return: CF clear if successful
	    ??? = compressed size of file/directory in bytes
	CF set on error
	    AX = error code
Note:	on volumes which do not support compression, the returned size is the
	  actual file size rounded up to the next cluster boundary
SeeAlso: AH=71h,AH=72h

INT 21 - DR DOS 3.41+ internal - GET ACCESS RIGHTS
	AX = 4302h
	DS:DX -> ASCIZ pathname
Return: CF clear if successful
	    CX = access rights (see #01421)
	    AX = CX (DR DOS 5.0)
	CF set on error
	    AX = error code
Desc:	Determine which operations the calling program may perform on a
	  specified file without being required to provide a password.
Notes:	this protection scheme has been coordinated on all current Digital
	  Research/Novell operating systems (DR DOS 3.41+, DRMDOS 5.x, and
	  FlexOS 2+)
	this function is documented in DR DOS 6.0 and corresponds to the
	  "Get/Set File Attributes" function, subfunction 2, documented in
	  Concurrent DOS.
	only FlexOS actually uses the "execution" bits; DR DOS 3.41+ treats
	  them as "read" bits.
	DR DOS 3.41-5.x only use bits 0-3.  Only DR DOS 6.0 using a
	  DRMDOS 5.x security system allowing for users and groups uses bits
	  4-11.
SeeAlso: AX=4303h,#01354 at INT 21/AH=11h

Bitfields for DR DOS file access rights:
Bit(s)	Description	(Table 01421)
 0	owner delete requires password
 1	owner execution requires password (FlexOS)
 2	owner write requires password
 3	owner read requires password
 4	group delete requires password
 5	group execution requires password (FlexOS)
 6	group write requires password
 7	group read requires password
 8	world delete requires password
 9	world execution requires password (FlexOS)
 10	world write requires password
 11	world read requires password

INT 21 - DR DOS 3.41+ internal - SET ACCESS RIGHTS AND PASSWORD
	AX = 4303h
	CX = access rights
	     bits 11-0: access rights (see #01421)
	     bit 15: new password is to be set
	DS:DX -> ASCIZ pathname
	[DTA] = new password if CX bit 15 is set (blank-padded to 8 characters)
Return: CF clear if successful
	CF set on error
	    AX = error code
Notes:	if the file is already protected, the old password must be added after
	  the pathname, separated by a ";".  As with all password handling in
	  DR DOS, the old password is processed by the kernel, not any
	  applications or utilities making the call.
	this function is documented in DR DOS 6.0 and corresponds to the
	  "Get/Set File Attributes" function, subfunction 3, documented in
	  Concurrent DOS.
SeeAlso: AH=0Fh,AH=17h,AX=4302h"DR DOS",AX=4305h,AX=4454h

INT 21 U - DR DOS 5.0-6.0 internal - GET ENCRYPTED PASSWORD
	AX = 4304h
	DS:DX -> ASCIZ filename
	???
Return: CF clear if successful
	    CX = AX = 0000h if no password assigned to file
	CF set on error
	    AX = error code (see #01680 at AH=59h/BX=0000h)
Note:	this function is only supported by DR DOS 5.0 and 6.0 and DRMDOS 5.1
SeeAlso: AX=4303h,AX=4305h

INT 21 U - DR DOS 5.0-6.0 internal - SET EXTENDED FILE ATTRIBUTES
	AX = 4305h
	DS:DX -> ASCIZ filename
	???
Return: CF clear if successful
	CF set on error
	    AX = error code (see #01680 at AH=59h/BX=0000h)
Desc:	this function allows the extended attributes, and optionally the
	  encrypted password, of a file to be set.
Note:	this function is only supported by DR DOS 5.0 and 6.0 and DRMDOS 5.1
SeeAlso: AX=4304h,AX=4311h

INT 21 O - DR DOS 6.0 - GET FILE OWNER
	AX = 4306h
	DS:DX -> ASCIZ filename
Return: CF clear if successful
	    AX = CX = value set with AX=4307h
	CF set on error
	    AX = error code (see #01680 at AH=59h/BX=0000h)
Note:	no longer supported by Novell DOS 7 / OpenDOS
SeeAlso: AX=4307h

INT 21 O - DR DOS 6.0 - SET FILE OWNER
	AX = 4307h
	CX = ??? (owner identification number?)
	DS:DX -> ASCIZ filename
Return: CF clear if successful
	CF set on error
	    AX = error code (see #01680 at AH=59h/BX=0000h)
Note:	no longer supported by Novell DOS 7 / OpenDOS
SeeAlso: AX=4306h

INT 21 - Banyan VINES 2.1+ - GET EXTENDED FILE ATTRIBUTES
	AX = 4310h
	DS:DX -> ASCIZ filename
Return: CF clear if successful
	    CH = attributes (see #01422)
	CF set on error
	    AX = error code (01h,02h,03h,05h) (see #01680 at AH=59h/BX=0000h)
Note:	the filename may be a directory but must be on a VINES file service
SeeAlso: AX=4300h,AX=4311h,AH=B6h,INT 2F/AX=110Fh

INT 21 - Banyan VINES 2.1+ - SET EXTENDED FILE ATTRIBUTES
	AX = 4311h
	CH = new attributes (see #01422)
	DS:DX -> ASCIZ filename
Return: CF clear if successful
	CF set on error
	    AX = error code (01h,02h,03h,05h) (see #01680 at AH=59h/BX=0000h)
Note:	the filename may be a directory but must be on a VINES file service
SeeAlso: AX=4301h,AX=4305h,AX=4310h,INT 2F/AX=110Eh

Bitfields for VINES extended file attributes:
Bit(s)	Description	(Table 01422)
 7	unused
 6	shareable
 5	execute-only
 4-0	unused

INT 21 - Q87, Q387 - INSTALLATION CHECK
	AX = 4321h
	BX = 0000h
	EAX = 87654321h (entire EAX value is required, not just AX)
Return: EAX = 12345678h if installed
Program: Q387 (renamed to Q87 as of v3.7) is a math coprocessor emulator from
	  Quickware
Note:	this function is available only in virtual-86 mode in older versions;
	  newer versions also provide it in MS Windows 16- and 32-bit protected
	  mode
SeeAlso: AX=4321h/BX=0001h,AX=4321h/BX=0002h,INT 67/AX=4321h

INT 21 - Q87, Q387 - ENABLE EMULATOR
	AX = 4321h
	BX = 0001h
	EAX = 87654321h (entire EAX value is required, not just AX)
Desc:	enable the emulator by setting the CPU MSW's EM bit and updating
	  the BIOS equipment list
Note:	this function is available only in virtual-86 mode in older versions;
	  newer versions also provide it in MS Windows 16- and 32-bit protected
	  mode
SeeAlso: AX=4321h/BX=0000h,AX=4321h/BX=0002h

INT 21 - Q87, Q387 - DISABLE EMULATOR
	AX = 4321h
	BX = 0002h
	EAX = 87654321h (entire EAX value is required, not just AX)
Desc:	disable the emulator by clearing the CPU MSW's EM bit and updating
	  the BIOS equipment list
Note:	this function is available only in virtual-86 mode in older versions;
	  newer versions also provide it in MS Windows 16- and 32-bit protected
	  mode
SeeAlso: AX=4321h/BX=0000h,AX=4321h/BX=0001h

INT 21 - Novell DOS 7 - UNDELETE PENDING DELETE FILE
	AX = 4380h
	???
Return: ???
SeeAlso: AH=41h,AX=4381h

INT 21 - Novell DOS 7 - PURGE PENDING DELETE FILE
	AX = 4381h
	???
Return: ???
SeeAlso: AH=41h,AX=4380h

INT 21 - DR-DOS >7.03 - RESERVED
	AX = 4382h-438Fh
Notes:	These previously unused functions are reserved for future versions of
	  DR-DOS (post 7.03).
	AX=4382h will be identical to the previous AX=4302h, which is now also
	  used by MS-DOS 7+ for a different purpose.
SeeAlso: INT 21h/4302h

INT 21 - MS-DOS 7.20 (Win98) - EXTENDED-LENGTH FILENAME OPERATIONS
	AX = 43FFh
	BP = 5053h ('PS')
	CL = function
	    39h "mkdir" create directory
		DS:DX -> ASCIZ pathname
	    56h rename file
		DS:DX -> ASCIZ filename of existing file (no wildcards)
		ES:DI -> ASCIZ new filename (no wildcards)
Return: CF clear if successful
	    AX destroyed
	CF set on error
	    AX = error code (03h,05h) (see #01680 at AH=59h/BX=0000h)
Note:	these functions are equivalent to INT 21/AH=39h and INT 21/AH=56h,
	  but with a maximum path length of 128 characters instead of 67;
	  unlike INT 21/AX=71xxh, these functions are available under bare
	  DOS and not just in a Windows DOS box
SeeAlso: AH=39h,AH=56h,AX=7139h,AX=7156h