Index for interrupt INT 31

Table of Contents by Order
31 - INT 31 - overwritten by CP/M jump instruction in INT 30
31 - INT 31 - VIRUS - "Vacsina" series - INSTALLATION CHECK (NOT A VECTOR!)
310000 - INT 31 P - DPMI 0.9+ - ALLOCATE LDT DESCRIPTORS
310001 - INT 31 P - DPMI 0.9+ - FREE LDT DESCRIPTOR
310002 - INT 31 P - DPMI 0.9+ - SEGMENT TO DESCRIPTOR
310003 - INT 31 P - DPMI 0.9+ - GET NEXT SELECTOR INCREMENT VALUE
310004 - INT 31 P - DPMI 0.9+ - LOCK SELECTOR
310005 - INT 31 P - DPMI 0.9+ - UNLOCK SELECTOR
310006 - INT 31 P - DPMI 0.9+ - GET SEGMENT BASE ADDRESS
310007 - INT 31 P - DPMI 0.9+ - SET SEGMENT BASE ADDRESS
310008 - INT 31 P - DPMI 0.9+ - SET SEGMENT LIMIT
310009 - INT 31 P - DPMI 0.9+ - SET DESCRIPTOR ACCESS RIGHTS
31000A - INT 31 P - DPMI 0.9+ - CREATE ALIAS DESCRIPTOR
31000B - INT 31 P - DPMI 0.9+ - GET DESCRIPTOR
31000C - INT 31 P - DPMI 0.9+ - SET DESCRIPTOR
31000D - INT 31 P - DPMI 0.9+ - ALLOCATE SPECIFIC LDT DESCRIPTOR
31000E - INT 31 P - DPMI 1.0+ - GET MULTIPLE DESCRIPTORS
31000F - INT 31 P - DPMI 1.0+ - SET MULTIPLE DESCRIPTORS
310100 - INT 31 P - DPMI 0.9+ - ALLOCATE DOS MEMORY BLOCK
310101 - INT 31 P - DPMI 0.9+ - FREE DOS MEMORY BLOCK
310102 - INT 31 P - DPMI 0.9+ - RESIZE DOS MEMORY BLOCK
310200 - INT 31 P - DPMI 0.9+ - GET REAL MODE INTERRUPT VECTOR
310201 - INT 31 P - DPMI 0.9+ - SET REAL MODE INTERRUPT VECTOR
310202 - INT 31 P - DPMI 0.9+ - GET PROCESSOR EXCEPTION HANDLER VECTOR
310203 - INT 31 P - DPMI 0.9+ - SET PROCESSOR EXCEPTION HANDLER VECTOR
310204 - INT 31 P - DPMI 0.9+ - GET PROTECTED MODE INTERRUPT VECTOR
310205 - INT 31 P - DPMI 0.9+ - SET PROTECTED MODE INTERRUPT VECTOR
310210 - INT 31 P - DPMI 1.0+ - GET PROTECTED MODE EXTENDED PROCESSOR EXCEPTION HANDLER
310211 - INT 31 P - DPMI 1.0+ - GET REAL MODE EXTENDED PROCESSOR EXCEPTION HANDLER
310212 - INT 31 P - DPMI 1.0+ - SET PROTECTED MODE EXTENDED PROCESSOR EXCEPTION HANDLER
310213 - INT 31 P - DPMI 1.0+ - SET REAL MODE EXTENDED PROCESSOR EXCEPTION HANDLER
310300 - INT 31 P - DPMI 0.9+ - SIMULATE REAL MODE INTERRUPT
310301 - INT 31 P - DPMI 0.9+ - CALL REAL MODE PROCEDURE WITH FAR RETURN FRAME
310302 - INT 31 P - DPMI 0.9+ - CALL REAL MODE PROCEDURE WITH IRET FRAME
310303 - INT 31 P - DPMI 0.9+ - ALLOCATE REAL MODE CALLBACK ADDRESS
310304 - INT 31 P - DPMI 0.9+ - FREE REAL MODE CALLBACK ADDRESS
310305 - INT 31 P - DPMI 0.9+ - GET STATE SAVE/RESTORE ADDRESSES
310306 - INT 31 P - DPMI 0.9+ - GET RAW MODE SWITCH ADDRESSES
310400 - INT 31 P - DPMI 0.9+ - GET DPMI VERSION
310401 - INT 31 P - DPMI 1.0+ - GET DPMI CAPABILITIES
310500 - INT 31 P - DPMI 0.9+ - GET FREE MEMORY INFORMATION
310501 - INT 31 P - DPMI 0.9+ - ALLOCATE MEMORY BLOCK
310502 - INT 31 P - DPMI 0.9+ - FREE MEMORY BLOCK
310503 - INT 31 P - DPMI 0.9+ - RESIZE MEMORY BLOCK
310504 - INT 31 P - DPMI 1.0+ - ALLOCATE LINEAR MEMORY BLOCK
310505 - INT 31 P - DPMI 1.0+ - RESIZE LINEAR MEMORY BLOCK
310506 - INT 31 P - DPMI 1.0+ - GET PAGE ATTRIBUTES
310507 - INT 31 P - DPMI 1.0+ - MODIFY PAGE ATTRIBUTES
310508 - INT 31 P - DPMI 1.0+ - MAP DEVICE IN MEMORY BLOCK
310509 - INT 31 P - DPMI 1.0+ - MAP CONVENTIONAL MEMORY IN MEMORY BLOCK
31050A - INT 31 P - DPMI 1.0+ - GET MEMORY BLOCK SIZE AND BASE
31050B - INT 31 P - DPMI 1.0+ - GET MEMORY INFORMATION
310600 - INT 31 P - DPMI 0.9+ - LOCK LINEAR REGION
310601 - INT 31 P - DPMI 0.9+ - UNLOCK LINEAR REGION
310602 - INT 31 P - DPMI 0.9+ - MARK REAL MODE REGION AS PAGEABLE
310603 - INT 31 P - DPMI 0.9+ - RELOCK REAL MODE REGION
310604 - INT 31 P - DPMI 0.9+ - GET PAGE SIZE
310700 - INT 31 Pu - DPMI 0.9+ - MARK PAGES AS PAGING CANDIDATES
310701 - INT 31 Pu - DPMI 0.9+ - DISCARD PAGES
310702 - INT 31 P - DPMI 0.9+ - MARK PAGE AS DEMAND PAGING CANDIDATE
310703 - INT 31 P - DPMI 0.9+ - DISCARD PAGE CONTENTS
310800 - INT 31 P - DPMI 0.9+ - PHYSICAL ADDRESS MAPPING
310801 - INT 31 P - DPMI 1.0+ - FREE PHYSICAL ADDRESS MAPPING
310900 - INT 31 P - DPMI 0.9+ - GET AND DISABLE VIRTUAL INTERRUPT STATE
310901 - INT 31 P - DPMI 0.9+ - GET AND ENABLE VIRTUAL INTERRUPT STATE
310902 - INT 31 P - DPMI 0.9+ - GET VIRTUAL INTERRUPT STATE
310A00 - INT 31 P - DPMI 0.9+ - GET VENDOR SPECIFIC API ENTRY POINT
310B00 - INT 31 P - DPMI 0.9+ - SET DEBUG WATCHPOINT
310B01 - INT 31 P - DPMI 0.9+ - CLEAR DEBUG WATCHPOINT
310B02 - INT 31 P - DPMI 0.9+ - GET STATE OF DEBUG WATCHPOINT
310B03 - INT 31 P - DPMI 0.9+ - RESET DEBUG WATCHPOINT
310C00 - INT 31 P - DPMI 1.0+ - INSTALL RESIDENT HANDLER INIT CALLBACK
310C01 - INT 31 P - DPMI 1.0+ - TERMINATE AND STAY RESIDENT
310D00 - INT 31 P - DPMI 1.0+ - ALLOCATE SHARED MEMORY
310D01 - INT 31 P - DPMI 1.0+ - FREE SHARED MEMORY
310D02 - INT 31 P - DPMI 1.0+ - SERIALIZE SHARED MEMORY
310D03 - INT 31 P - DPMI 1.0+ - FREE SERIALIZATION ON SHARED MEMORY
310E00 - INT 31 P - DPMI 1.0+ - GET COPROCESSOR STATUS
310E01 - INT 31 P - DPMI 1.0+ - SET EMULATION
3157 - INT 31 - Netroom3 DPMI.EXE v3.00 - ???
315702 - INT 31 - Netroom3 DPMI.EXE v3.00 - SWITCH TO PROTECTED MODE
31EE00 - INT 31 - DOS32 v3.0+ - GET DOS32 VERSION AND SELECTOR VALUES
31EE02 - INT 31 - DOS32 v3.0+ - GET DOS32 ADDRESS INFORMATION
31EE10 - INT 31 - DOS32 v3.2+ - SET UP A DOS32 LOADABLE LIBRARY
31EE11 - INT 31 - DOS32 v3.2+ - LOAD LIBRARY FILE
31EE20 - INT 31 - DOS32 v3.0+ - GET REAL MODE CALL BACK ADDRESS WITH RETF STACK FRAME
31EE21 - INT 31 - DOS32 v3.0+ - GET REAL MODE CALL BACK ADDRESS WITH IRET STACK FRAME
31EE30 - INT 31 - DOS32 v3.0+ - TERMINATE AND STAY RESIDENT
31EE40 - INT 31 - DOS32 v3.0+ - UNDO PREVIOUS MEMORY ALLOCATION or DMA BUFFER
31EE41 - INT 31 - DOS32 v3.0+ - ALLOCATE 16KB DMA BLOCK
31EE42 - INT 31 - DOS32 v3.0+ - ALLOCATE MEMORY BLOCK
31FF00 - INT 31 P - CauseWay - "Info" - GET SYSTEM SELECTORS/FLAGS
31FF01 - INT 31 P - CauseWay - "IntXX" - SIMULATE REAL-MODE INTERRUPT
31FF02 - INT 31 P - CauseWay - "FarCallReal" - SIMULATE REAL-MODE FAR CALL
31FF03 - INT 31 P - CauseWay - "GetSel" - ALLOCATE NEW SELECTOR
31FF04 - INT 31 P - CauseWay - "RelSel" - RELEASE A SELECTOR
31FF05 - INT 31 P - CauseWay - "CodeSel" - CONVERT SELECTOR TO EXECUTABLE CODE SELECTOR
31FF06 - INT 31 P - CauseWay - "AliasSel" - CREATE READ/WRITE DATA ALIAS SELECTOR
31FF07 - INT 31 P - CauseWay - "GetSelDet" - GET SELECTOR BASE AND LIMIT
31FF08 - INT 31 P - CauseWay - "GetSelDet32" - GET SELECTOR BASE AND LIMIT (32-bit)
31FF09 - INT 31 P - CauseWay - "SetSelDet" - SET SELECTOR BASE AND LIMIT
31FF0A - INT 31 P - CauseWay - "SetSelDet32" - SET SELECTOR BASE AND LIMIT (32-bit)
31FF0B - INT 31 P - CauseWay - "GetMem" - ALLOCATE BLOCK OF MEMORY
31FF0C - INT 31 P - CauseWay - "GetMem32" - ALLOCATE BLOCK OF MEMORY (32-bit)
31FF0D - INT 31 P - CauseWay - "ResMem" - RESIZE MEMORY BLOCK
31FF0E - INT 31 P - CauseWay - "ResMem32" - RESIZE MEMORY BLOCK (32-bit)
31FF0F - INT 31 P - CauseWay - "RelMem" - RELEASE PREVIOUSLY ALLOCATED MEMORY
31FF10 - INT 31 P - CauseWay - "GetMemLinear" - ALLOCATE MEMORY WITHOUT SELECTOR
31FF11 - INT 31 P - CauseWay - "GetMemLinear32" - ALLOCATE MEMORY WITHOUT SELECTOR
31FF12 - INT 31 P - CauseWay - "ResMemLinear" - RESIZE LINEAR MEMORY BLOCK
31FF13 - INT 31 P - CauseWay - "ResMemLinear32" - RESIZE LINEAR MEMORY BLOCK (32-bit)
31FF14 - INT 31 P - CauseWay - "RelMemLinear" - RELEASE LINEAR MEMORY BLOCK
31FF15 - INT 31 P - CauseWay - "RelMemLinear32" - RELEASE LINEAR MEMORY BLOCK (32-bit)
31FF16 - INT 31 P - CauseWay - "GetMemNear" - ALLOCATE APPLICATION-RELATIVE MEMORY
31FF17 - INT 31 P - CauseWay - "ResMemNear" - RESIZE APPLICATION-RELATIVE MEMORY BLOCK
31FF18 - INT 31 P - CauseWay - "RelMemNear" - RELEASE APPLICATION-RELATIVE MEMORY BLOCK
31FF19 - INT 31 P - CauseWay - "Linear2Near" - CONVERT LINEAR TO APP-RELATIVE ADDRESS
31FF1A - INT 31 P - CauseWay - "Near2Linear" - CONVERT APP-RELATIVE TO LINEAR ADDRESS
31FF1B - INT 31 P - CauseWay - "LockMem" - LOCK REGION OF MEMORY
31FF1C - INT 31 P - CauseWay - "LockMem32" - LOCK REGION OF MEMORY (32-bit)
31FF1D - INT 31 P - CauseWay - "UnLockMem" - UNLOCK REGION OF MEMORY
31FF1E - INT 31 P - CauseWay - "UnLockMem32" - UNLOCK REGION OF MEMORY (32-bit)
31FF1F - INT 31 P - CauseWay - "LockMemNear" - LOCK APPLICATION-RELATIVE MEMORY REGION
31FF20 - INT 31 P - CauseWay - "UnLockMemNear" - UNLOCK APP-RELATIVE MEMORY REGION
31FF21 - INT 31 P - CauseWay - "GetMemDOS" - ALLOCATE CONVENTIONAL MEMORY
31FF22 - INT 31 P - CauseWay - "ResMemDOS" - RESIZE CONVENTIONAL MEMORY BLOCK
31FF23 - INT 31 P - CauseWay - "RelMemDOS" - RELEASE CONVENTIONAL MEMORY BLOCK
31FF24 - INT 31 P - CauseWay - "ExecOverlay" - LOAD AND OPTIONALLY EXECUTE APP CODE
31FF25 - INT 31 P - CauseWay - "GetDOSTrans" - GET DOS TRANSFER BUFFER
31FF26 - INT 31 P - CauseWay - "SetDOSTrans" - SET DOS TRANSFER BUFFER
31FF27 - INT 31 P - CauseWay v1.3 - "GetMCBSize" - GET CURRENT MCB ALLOCATION BLOCK SIZE
31FF28 - INT 31 P - CauseWay v1.3 - "SetMCBSize" - SET MCB MEMORY ALLOCATION BLOCK SIZE
31FF29 - INT 31 P - CauseWay v1.3 - "GetSels" - ALLOCATE MULTIPLE SELECTORS
31FF2A - INT 31 P - CauseWay v1.3 - "cwLoad" - LOAD ANOTHER CAUSEWAY PROGRAM AS OVERLAY
31FF2B - INT 31 P - CauseWay v1.3 - "cwcInfo" - VALIDATE AND GET SIZE OF CWC FILE
31FF2C - INT 31 P - CauseWay v1.3 - "GetMemSO" - ALLOCATE MEMORY AND RETURN SEL:OFFSET
31FF2D - INT 31 P - CauseWay v1.3 - "ResMemSO" - RESIZE SELECTOR:OFFSET MEMORY BLOCK
31FF2E - INT 31 P - CauseWay v1.3 - "RelMemSO" - RELEASE SELECTOR:OFFSET MEMORY BLOCK
31FFFB - INT 31 P - Causeway v1.3 - "cwcLoad" - LOAD/EXPAND CWC-COMPRESSED FILE

INT 31 - overwritten by CP/M jump instruction in INT 30

INT 31 - VIRUS - "Vacsina" series - INSTALLATION CHECK (NOT A VECTOR!)
Note:	if one of the Vacsina viruses is resident, the low byte of this
	  interrupt still contains the last byte of the INT 30 CP/M JMP
	  instruction, but the remaining three bytes are 7Fh 39h followed
	  by the Vacsina version number
SeeAlso: INT 21/AX=FFFFh"VIRUS",INT 32"VIRUS"

INT 31 P - DPMI 0.9+ - ALLOCATE LDT DESCRIPTORS
	AX = 0000h
	CX = number of descriptors to allocate
Return: CF clear if successful
	    AX = base selector
	CF set on error
	    AX = error code (DPMI 1.0+) (see #03143)
Notes:	DPMI is the DOS Protected-Mode Interface
	the base and limit of the returned descriptors will be 0, and the type
	  will be "data"
	add the value returned by INT 31/AX=0003h to move to subsequent
	  descriptors if multiple descriptors were allocated
	not supported by MS Windows 3.0 in Standard mode
SeeAlso: AX=0001h,AX=000Dh,INT 21/AX=3501h

(Table 03143)
Values for DPMI 1.0 error code:
 0000h-7FFFh DOS error passed through by DPMI
 8001h	unsupported function
 8002h	object in wrong state for function
 8003h	system integrity would be endangered
 8004h	deadlock detected
 8005h	pending serialization request cancelled
 8010h	out of DPMI internal resources
 8011h	descriptor unavailable
 8012h	linear memory unavailable
 8013h	physical memory unavailable
 8014h	backing store unavailable
 8015h	callback unavailable
 8016h	handle unavailable
 8017h	maximum lock count exceeded
 8018h	shared memory already serialized exclusively by another
 8019h	shared memory already serialized shared by another client
 8021h	invalid value for numeric or flag parameter
 8022h	invalid segment selector
 8023h	invalid handle
 8024h	invalid callback
 8025h	invalid linear address
 8026h	request not supported by hardware

INT 31 P - DPMI 0.9+ - FREE LDT DESCRIPTOR
	AX = 0001h
	BX = selector to free
Return: CF clear if successful
	CF set on error
	    AX = error code (DPMI 1.0+) (8022h) (see #03143)
Notes:	only one descriptor is freed per call
	the program's initial CS, DS, and SS descriptors may be freed
	(DPMI 1.0+) any segment registers containing the freed selector are
	  set to 0000h
	not supported by MS Windows 3.0 in Standard mode
SeeAlso: AX=0000h,AX=000Ah,AX=000Dh,INT 21/AX=3502h

INT 31 P - DPMI 0.9+ - SEGMENT TO DESCRIPTOR
	AX = 0002h
	BX = real mode segment
Return: CF clear if successful
	    AX = selector corresponding to real mode segment (64K limit)
	CF set on error
	    AX = error code (DPMI 1.0+) (8011h) (see #03143)
Notes:	multiple calls for the same real mode segment return the same selector
	the returned descriptor can never be modified or freed
	not supported by MS Windows 3.0 in Standard mode

INT 31 P - DPMI 0.9+ - GET NEXT SELECTOR INCREMENT VALUE
	AX = 0003h
Return: CF clear
	    AX = value to add to get next sequential selector
Notes:	the increment will be a power of two
	not supported by MS Windows 3.0 in Standard mode
SeeAlso: AX=0000h

INT 31 P - DPMI 0.9+ - LOCK SELECTOR
	AX = 0004h
	BX = selector to lock (prevent paging)
Return: ???
Note:	although marked as reserved in versions 0.9 and 1.0 of the DPMI
	  specification, this function is called by MS Windows TASKMAN,
	  PROGMAN, and KERNEL
SeeAlso: AX=0005h,AX=0600h

INT 31 P - DPMI 0.9+ - UNLOCK SELECTOR
	AX = 0005h
	BX = selector to unlock (permit paging)
Return: ???
Note:	although marked as reserved in versions 0.9 and 1.0 of the DPMI
	  specification, this function is called by MS Windows TASKMAN,
	  PROGMAN, and KERNEL
SeeAlso: AX=0004h,AX=0601h

INT 31 P - DPMI 0.9+ - GET SEGMENT BASE ADDRESS
	AX = 0006h
	BX = selector
Return: CF clear if successful
	    CX:DX = linear base address of segment
	CF set on error
	    AX = error code (DPMI 1.0+) (8022h) (see #03143)
Note:	not supported by MS Windows 3.0 in Standard mode
SeeAlso: AX=0007h,INT 21/AX=3504h

INT 31 P - DPMI 0.9+ - SET SEGMENT BASE ADDRESS
	AX = 0007h
	BX = selector
	CX:DX = linear base address
Return: CF clear if successful
	CF set on error
	    AX = error code (DPMI 1.0+) (8022h,8025h) (see #03143)
Notes:	only modify descriptors allocated with INT 31/AX=0000h
	only the low 24 bits of the address will be used by 16-bit DPMI
	  implementations even on a 386 or higher
	DPMI 1.0+ automatically reloads any segment registers containing the
	  selector being modified
	not supported by MS Windows 3.0 in Standard mode
SeeAlso: AX=0006h,AX=0008h,AX=0009h,AX=000Ch,INT 21/AX=3503h
SeeAlso: INT 21/AH=E9h"OS/286",INT 2C/AX=0002h

INT 31 P - DPMI 0.9+ - SET SEGMENT LIMIT
	AX = 0008h
	BX = selector
	CX:DX = segment limit
Return: CF clear if successful
	CF set on error
	    AX = error code (DPMI 1.0+) (8021h,8022h,8025h) (see #03143)
Notes:	CX must be zero for 16-bit DPMI implementations
	limits greater than 1MB must be page aligned (low 12 bits set)
	only modify descriptors allocated with INT 31/AX=0000h
	DPMI 1.0+ automatically reloads any segment registers containing the
	  selector being modified
	not supported by MS Windows 3.0 in Standard mode
SeeAlso: AX=0007h,AX=0009h,AX=000Ch,INT 21/AX=3505h,INT 21/AH=E9h"OS/286"
SeeAlso: INT 2C/AX=0003h,#00501 at INT 15/AH=89h

INT 31 P - DPMI 0.9+ - SET DESCRIPTOR ACCESS RIGHTS
	AX = 0009h
	BX = selector
	CL = access rights/type byte (see #00502 at INT 15/AH=89h)
	CH = 80386 extended rights/type byte (see #00505 at INT 15/AH=89h)
	    (32-bit DPMI implementations only)
Return: CF clear if successful
	CF set on error
	    AX = error code (DPMI 1.0+) (8021h,8022h,8025h) (see #03143)
Notes:	if the Present bit is clear, CL bits 0-3 may have any value
	DPMI 1.0+ automatically reloads any segment registers containing the
	  selector being modified
	not supported by MS Windows 3.0 in Standard mode
SeeAlso: AX=0007h,AX=0008h,AX=000Ch,INT 21/AX=2514h,INT 2C/AX=0004h
SeeAlso: INT 2C/AX=0005h

INT 31 P - DPMI 0.9+ - CREATE ALIAS DESCRIPTOR
	AX = 000Ah
	BX = selector
Return: CF clear if successful
	    AX = new data selector
	CF set on error
	    AX = error code (DPMI 1.0+) (8011h,8022h) (see #03143)
Notes:	fails if selector in BX is not a code segment or is invalid
	use INT 31/AX=0001h to free new selector
	future changes to the original selector will not be reflected in the
	  returned alias selector
	not supported by MS Windows 3.0 in Standard mode
SeeAlso: AX=0001h

INT 31 P - DPMI 0.9+ - GET DESCRIPTOR
	AX = 000Bh
	BX = LDT selector
	ES:(E)DI -> 8-byte buffer for copy of descriptor
Return: CF clear if successful
	    buffer filled
	CF set on error
	    AX = error code (DPMI 1.0+) (8022h) (see #03143)
Notes:	16-bit programs use ES:DI as pointer, 32-bit must use ES:EDI
	not supported by MS Windows 3.0 in Standard mode
SeeAlso: AX=000Ch

INT 31 P - DPMI 0.9+ - SET DESCRIPTOR
	AX = 000Ch
	BX = LDT selector
	ES:(E)DI -> 8-byte buffer containing descriptor
Return: CF clear if successful
	CF set on error
	    AX = error code (DPMI 1.0+) (8021h,8022h,8025h) (see #03143)
Notes:	16-bit programs use ES:DI as pointer, 32-bit must use ES:EDI
	only modify descriptors allocated with INT 31/AX=0000h
	DPMI 1.0+ automatically reloads any segment registers containing the
	  selector being modified
	not supported by MS Windows 3.0 in Standard mode
SeeAlso: AX=000Bh

INT 31 P - DPMI 0.9+ - ALLOCATE SPECIFIC LDT DESCRIPTOR
	AX = 000Dh
	BX = LDT selector
Return: CF clear if successful
	    descriptor allocated
	CF set on error
	    AX = error code (DPMI 1.0+) (8011h,8022h) (see #03143)
Notes:	free descriptor with INT 31/AX=0001h
	the first 16 descriptors (04h-7Ch) are reserved for this function, but
	  some may already be in use by other applications under DPMI 0.9;
	  DPMI 1.0 guarantees 16 descriptors per client
	not supported by MS Windows 3.0 in Standard mode
SeeAlso: AX=0000h,AX=0001h

INT 31 P - DPMI 1.0+ - GET MULTIPLE DESCRIPTORS
	AX = 000Eh
	CX = number of descriptors to copy
	ES:(E)DI -> descriptor buffer (see #03144)
Return: CF clear if successful
	    descriptors copied
	CF set on error
	    AX = error code (8022h) (see #03143)
	    CX = number of descriptors successfully copied
Notes:	16-bit programs use ES:DI as pointer, 32-bit must use ES:EDI
	if the function fails, the first CX descriptors are valid; the
	  remainder are not modified
SeeAlso: AX=000Bh,AX=000Fh

Format of DPMI descriptor buffer entry (one per descriptor to get):
Offset	Size	Description	(Table 03144)
 00h	WORD	selector (set by client)
 02h	QWORD	descriptor (set by host)

INT 31 P - DPMI 1.0+ - SET MULTIPLE DESCRIPTORS
	AX = 000Fh
	CX = number of descriptors to copy
	ES:(E)DI -> descriptor buffer (see #03145)
Return: CF clear if successful
	    descriptors copied
	CF set on error
	    AX = error code (8021h,8022h,8025h) (see #03143)
	    CX = number of descriptors successfully copied
Notes:	16-bit programs use ES:DI as pointer, 32-bit must use ES:EDI
	if the function fails, the first CX descriptors are valid; the
	  remainder are not modified
	DPMI 1.0+ automatically reloads any segment registers containing a
	  selector being modified
SeeAlso: AX=000Ch,AX=000Eh

Format of DPMI descriptor buffer entry (one per descriptor to set):
Offset	Size	Description	(Table 03145)
 00h	WORD	selector
 02h	QWORD	descriptor

INT 31 P - DPMI 0.9+ - ALLOCATE DOS MEMORY BLOCK
	AX = 0100h
	BX = number of paragraphs to allocate
Return: CF clear if successful
	    AX = real mode segment of allocated block
	    DX = first selector for allocated block
	CF set on error
	    AX = DOS error code (07h,08h) (see #01680 at INT 21/AH=59h/BX=0000h)
		(DPMI 1.0+) DPMI error code (8011h) (see #03143)
	    BX = size (in paragraphs) of largest available block
Notes:	multiple contiguous selectors are allocated for blocks of more than 64K
	  if the caller is a 16-bit program
	never modify or deallocate returned descriptors
	not supported by MS Windows 3.0 in Standard mode
SeeAlso: AX=0101h,AX=0501h

INT 31 P - DPMI 0.9+ - FREE DOS MEMORY BLOCK
	AX = 0101h
	DX = selector of block
Return: CF set if successful
	CF set on error
	    AX = DOS error code (07h,09h) (see #01680 at INT 21/AH=59h/BX=0000h)
Notes:	all descriptors allocated for the block are automatically freed
	DPMI 1.0+ automatically zeros any segment registers containing a
	  selector freed by this function
	not supported by MS Windows 3.0 in Standard mode
SeeAlso: AX=0100h,AX=0102h,AX=0502h

INT 31 P - DPMI 0.9+ - RESIZE DOS MEMORY BLOCK
	AX = 0102h
	BX = new block size in paragraphs
	DX = selector of block
Return: CF clear if successful
	CF set on error
	    AX = DOS error code (07h,08h,09h)
		  (see #01680 at INT 21/AH=59h/BX=0000h)
		(DPMI 1.0+) DPMI error code (8011h,8022h) (see #03143)
	    BX = maximum block size (in paragraphs) possible
Notes:	increasing the size of a block past a 64K boundary will fail if the
	  next descriptor in the LDT is already in use
	shrinking a block past a 64K boundary will cause some selectors to be
	  freed; DPMI 1.0+ automatically zeros any segment registers containing
	  a selector freed by this function
	not supported by MS Windows 3.0 in Standard mode
SeeAlso: AX=0100h

INT 31 P - DPMI 0.9+ - GET REAL MODE INTERRUPT VECTOR
	AX = 0200h
	BL = interrupt number
Return: CF clear
	CX:DX = segment:offset of real mode interrupt handler
Note:	the DPMI implementation is required to support all 256 vectors
SeeAlso: AX=0201h,AX=0204h,INT 21/AX=2503h

INT 31 P - DPMI 0.9+ - SET REAL MODE INTERRUPT VECTOR
	AX = 0201h
	BL = interrupt number
	CX:DX = segment:offset of real mode handler
Return: CF clear
Note:	all memory that may be touched by a hardware interrupt handler must be
	  locked down with INT 31/AX=0600h
SeeAlso: AX=0200h,AX=0205h,AX=0600h,INT 21/AX=2505h

INT 31 P - DPMI 0.9+ - GET PROCESSOR EXCEPTION HANDLER VECTOR
	AX = 0202h
	BL = exception number (00h-1Fh)
Return: CF clear if successful
	    CX:(E)DX = selector:offset of handler
	CF set on error
	    AX = error code (DPMI 1.0+) (8021h) (see #03143)
Notes:	16-bit programs receive the pointer in CX:DX, 32-bit programs in CX:EDX
	DPMI 1.0+ supports this function only for backward compatibility; use
	   AX=0210h or AX=0211h instead
	not supported by MS Windows 3.0 in Standard mode
SeeAlso: AX=0203h,AX=0210h,AX=0211h,INT 2F/AX=FB42h/BX=0021h

INT 31 P - DPMI 0.9+ - SET PROCESSOR EXCEPTION HANDLER VECTOR
	AX = 0203h
	BL = exception number (00h-1Fh)
	CX:(E)DX = selector:offset of handler
Return: CF clear if successful
	CF set on error
	    AX = error code (DPMI 1.0+) (8021h,8022h) (see #03143)
Notes:	32-bit programs must supply an offset in EDX and use a 32-bit interrupt
	  stack frame on chaining to the next exception handler
	the handler should return using a FAR return
	all fault stack frames contain an error code, but it is only valid for
	  exceptions 08h and 0Ah-0Eh
	handlers will only be called if the exception occurs in protected mode,
	  and the DPMI host does not transparently handle the exception
	the handler may change certain values on the stack frame
	  (see #03146,#03147)
	DPMI 1.0+ supports this function only for backward compatibility; use
	   AX=0212h or AX=0213h instead
	not supported by MS Windows 3.0 in Standard mode
SeeAlso: AX=0202h,AX=0212h,AX=0213h,INT 2F/AX=FB42h/BX=0022h

Format of stack frame for 16-bit programs: (offset from SS:SP)
Offset	Size	Description	(Table 03146)
 00h	DWORD	return CS:IP (do not change)
 04h	WORD	error code
 06h	DWORD	CS:IP of exception
 0Ah	WORD	flags
 0Ch	DWORD	SS:SP

Format of stack frame for 32-bit programs: (offset from SS:ESP)
Offset	Size	Description	(Table 03147)
 00h	DWORD	return EIP (do not change)
 04h	WORD	return CS selector (do not change)
 06h	WORD	reserved (do not change)
 08h	DWORD	error code
 0Ch	DWORD	EIP of exception
 10h	WORD	CS selector of exception
 12h	WORD	reserved (do not change)
 14h	DWORD	EFLAGS
 18h	DWORD	ESP
 1Ch	WORD	SS
 1Eh	WORD	reserved (do not change)

INT 31 P - DPMI 0.9+ - GET PROTECTED MODE INTERRUPT VECTOR
	AX = 0204h
	BL = interrupt number
Return: CF clear
	CX:(E)DX = selector:offset of handler
Notes:	16-bit programs use CX:DX, 32-bit programs use CX:EDX
	DPMI implementations are required to support all 256 vectors
	not supported by MS Windows 3.0 in Standard mode
SeeAlso: AX=0200h,AX=0205h,INT 21/AX=2502h,INT 2C/AX=0006h
SeeAlso: INT 2F/AX=FB42h/BX=0024h

INT 31 P - DPMI 0.9+ - SET PROTECTED MODE INTERRUPT VECTOR
	AX = 0205h
	BL = interrupt number
	CX:(E)DX = selector:offset of handler
Return: CF clear if successful
	CF set on error
	    AX = error code (DPMI 1.0+) (8022h) (see #03143)
Notes:	16-bit programs use CX:DX, 32-bit programs use CX:EDX
	32-bit programs must use a 32-bit interrupt stack frame when chaining
	  to the next handler
	DPMI implementations are required to support all 256 vectors
	hardware interrupts are reflected to the virtual machine's primary
	  client, software interrupts to the current client
	not supported by MS Windows 3.0 in Standard mode
SeeAlso: AX=0201h,AX=0204h,INT 21/AX=2504h,INT 2C/AX=0007h
SeeAlso: INT 2F/AX=FB42h/BX=0025h

INT 31 P - DPMI 1.0+ - GET PROTECTED MODE EXTENDED PROCESSOR EXCEPTION HANDLER
	AX = 0210h
	BL = exception number (00h-1Fh)
Return: CF clear if successful
	    CX:(E)DX = selector:offset of exception handler
	CF set on error
	    AX = error code (8021h) (see #03143)
Note:	DPMI host reflects exception to current client's handler
SeeAlso: AX=0202h,AX=0211h,AX=0212h

INT 31 P - DPMI 1.0+ - GET REAL MODE EXTENDED PROCESSOR EXCEPTION HANDLER
	AX = 0211h
	BL = exception number (00h-1Fh)
Return: CF clear if successful
	    CX:(E)DX = selector:offset of exception handler
	CF set on error
	    AX = error code (8021h) (see #03143)
Notes:	returns address of protected-mode handler for real-mode exception
	DPMI host performs a switch to protected mode, reflects the exception
	  to the virtual machine's primary client, and returns to real mode
	  on the handler's completion
SeeAlso: AX=0202h,AX=0210h,AX=0213h

INT 31 P - DPMI 1.0+ - SET PROTECTED MODE EXTENDED PROCESSOR EXCEPTION HANDLER
	AX = 0212h
	BL = exception or fault number (00h-1Fh)
	CX:(E)DX = exception handler selector:offset
Return: CF clear if successful
	CF set on error
	    AX = error code (8021h,8022h) (see #03143)
Note:	DPMI host sends exception to current client's handler
SeeAlso: AX=0203h,AX=0210h,AX=0213h

INT 31 P - DPMI 1.0+ - SET REAL MODE EXTENDED PROCESSOR EXCEPTION HANDLER
	AX = 0213h
	BL = exception or fault number (00h-1Fh)
	CX:(E)DX = exception handler selector:offset
Return: CF clear if successful
	CF set on error
	    AX = error code (8021h,8022h) (see #03143)
Notes:	specifies address of protected-mode handler for real-mode exception
	DPMI host performs a switch to protected mode, reflects the exception
	  to the virtual machine's primary client, and returns to real mode
	  on the handler's completion
SeeAlso: AX=0203h,AX=0211h,AX=0212h

INT 31 P - DPMI 0.9+ - SIMULATE REAL MODE INTERRUPT
	AX = 0300h
	BL = interrupt number
	BH = flags
	    bit 0: reset the interrupt controller and A20 line (DPMI 0.9)
		    reserved, must be 0 (DPMI 1.0+)
	    others: reserved, must be 0
	CX = number of words to copy from protected mode to real mode stack
	ES:(E)DI = selector:offset of real mode call structure (see #03148)
Return: CF clear if successful
	    real mode call structure modified (all fields except SS:SP, CS:IP
	      filled with return values from real mode interrupt)
	CF set on error
	    AX = error code (DPMI 1.0+) (8012h,8013h,8014h,8021h)(see #03143)
	protected mode stack unchanged
Notes:	16-bit programs use ES:DI as pointer, 32-bit programs use ES:EDI
	CS:IP in the real mode call structure is ignored for this call,
	  instead, the indicated interrupt vector is used for the address
	the flags in the call structure are pushed on the real mode stack to
	  form an interrupt stack frame, and the trace and interrupt flags are
	  clear on entry to the handler
	DPMI will provide a small (30 words) real mode stack if SS:SP is zero
	the real mode handler must return with the stack in the same state as
	  it was on being called
SeeAlso: AX=0302h,AX=FF01h,INT 21/AX=2511h,INT 21/AH=E3h"OS/286"
SeeAlso: INT 2C/AX=0026h,INT 2F/AX=FB42h/BX=000Dh

Format of DPMI real mode call structure:
Offset	Size	Description	(Table 03148)
 00h	DWORD	EDI
 04h	DWORD	ESI
 08h	DWORD	EBP
 0Ch	DWORD	reserved (00h)
 10h	DWORD	EBX
 14h	DWORD	EDX
 18h	DWORD	ECX
 1Ch	DWORD	EAX
 20h	WORD	flags
 22h	WORD	ES
 24h	WORD	DS
 26h	WORD	FS
 28h	WORD	GS
 2Ah	WORD	IP
 2Ch	WORD	CS
 2Eh	WORD	SP
 30h	WORD	SS

INT 31 P - DPMI 0.9+ - CALL REAL MODE PROCEDURE WITH FAR RETURN FRAME
	AX = 0301h
	BH = flags
	    bit 0: reset the interrupt controller and A20 line (DPMI 0.9)
		    reserved, must be 0 (DPMI 1.0+)
	    others: reserved must be 0
	CX = number of words to copy from protected mode to real mode stack
	ES:(E)DI = selector:offset of real mode call structure
		  (see #03148 at INT 31/AX=0300h)
Return: CF clear if successful
	    real mode call structure modified (all fields except SS:SP, CS:IP
	      filled with return values from real mode interrupt)
	CF set on error
	    AX = error code (DPMI 1.0+) (8012h,8013h,8014h,8021h)(see #03143)
	protected mode stack unchanged
Notes:	16-bit programs use ES:DI as pointer, 32-bit programs use ES:EDI
	the real mode procedure must exit with a FAR return
	DPMI will provide a small (30 words) real mode stack if SS:SP is zero
	the real mode handler must return with the stack in the same state as
	  it was on being called
SeeAlso: AX=0300h,AX=0302h,AX=FF02h,INT 21/AX=250Eh,INT 21/AH=E1h"OS/286"
SeeAlso: INT 2C/AX=0025h

INT 31 P - DPMI 0.9+ - CALL REAL MODE PROCEDURE WITH IRET FRAME
	AX = 0302h
	BH = flags
	    bit 0: reset the interrupt controller and A20 line (DPMI 0.9)
		    reserved, must be 0 (DPMI 1.0+)
	    others: reserved, must be 0
	CX = number of words to copy from protected mode to real mode stack
	ES:(E)DI = selector:offset of real mode call structure
		  (see #03148 at INT 31/AX=0300h)
Return: CF clear if successful
	    real mode call structure modified (all fields except SS:SP, CS:IP
	      filled with return values from real mode interrupt)
	CF set on error
	    AX = error code (DPMI 1.0+) (8012h,8013h,8014h,8021h)(see #03143)
	protected mode stack unchanged
Notes:	16-bit programs use ES:DI as pointer, 32-bit programs use ES:EDI
	the flags in the call structure are pushed on the real mode stack to
	  form an interrupt stack frame, and the trace and interrupt flags are
	  clear on entry to the handler
	the real mode procedure must exit with an IRET
	DPMI will provide a small (30 words) real mode stack if SS:SP is zero
	the real mode handler must return with the stack in the same state as
	  it was on being called
SeeAlso: AX=0300h

INT 31 P - DPMI 0.9+ - ALLOCATE REAL MODE CALLBACK ADDRESS
	AX = 0303h
	DS:(E)SI = selector:offset of procedure to call
	ES:(E)DI = selector:offset of real mode call structure (see #03148)
Return: CF clear if successful
	    CX:DX = segment:offset of real mode call address (see #03149)
	CF set on error
	    AX = error code (DPMI 1.0+) (8015h) (see #03143)
Notes:	the real mode call structure is static, causing reentrancy problems;
	  its contents are only valid at the time of a callback
	the called procedure must modify the real mode CS:IP before returning
	values are returned to real mode by modifying the real mode call struc
	DPMI hosts must provide at least 16 callbacks per client
	the limited DPMI host built into Phar Lap's 286|DOS-Extender v2.5 does
	  not support this function
BUG:	Windows NT 4.0 either ignores or clears the high 16 bits of EDI,
	  causing an illegal instruction error if the real mode call
	  structure's offset in ES is greater than 64K
SeeAlso: AX=0304h,AX=0C00h

(Table 03149)
Values DPMI real-mode callback procedure is called with:
	DS:(E)SI = selector:offset of real mode SS:SP
	ES:(E)DI = selector:offset of real mode call structure
	SS:(E)SP = locked protected mode API stack
	interrupts disabled
Return: (with IRET)
	ES:(E)DI = selector:offset of real mode call structure to restore

INT 31 P - DPMI 0.9+ - FREE REAL MODE CALLBACK ADDRESS
	AX = 0304h
	CX:DX = real mode callback address
Return: CF clear if successful
	CF set on error
	    AX = error code (DPMI 1.0+) (8024h) (see #03143)
Note:	the limited DPMI host built into Phar Lap's 286|DOS-Extender v2.5 does
	  not support this function
SeeAlso: AX=0303h

INT 31 P - DPMI 0.9+ - GET STATE SAVE/RESTORE ADDRESSES
	AX = 0305h
Return: CF clear
	AX = size in bytes of state buffer
	BX:CX = real mode address of procedure to save/restore state
	SI:(E)DI = protected mode procedure to save/restore state (see #03150)
Notes:	the buffer size will be zero if it is not necessary to preserve state
	16-bit programs should call SI:DI, 32-bit programs should call SI:EDI
	this function is only needed if using the raw mode switch service
SeeAlso: AX=0306h

(Table 03150)
Call DPMI state-save procedures with:
	AL = direction
	    00h save state
	    01h restore state
	ES:(E)DI -> state buffer
Return: all registers preserved

INT 31 P - DPMI 0.9+ - GET RAW MODE SWITCH ADDRESSES
	AX = 0306h
Return: CF clear
	BX:CX -> procedure to switch from real to protected mode (see #03151)
	SI:(E)DI -> procedure to switch from protected to real mode
Notes:	16-bit programs should jump to SI:DI, 32-bit programs should use SI:EDI
	the caller must save and restore the state of the task with AX=0305h
	not supported by MS Windows 3.0 in Standard mode
SeeAlso: AX=0305h

(Table 03151)
Values to JUMP at mode-switch procedures with:
	AX = new DS
	CX = new ES
	DX = new SS
	(E)BX = new (E)SP
	SI:(E)DI = new CS:(E)IP
Notes:	BP/EBP is preserved across the call, but AX/EAX, BX/EBX, CX/ECX,
	  DX/EDX, SI/ESI, and DI/EDI will be undefined; FS and GS will be 0000h
	interrupts will stay disabled during the entire mode switch if they
	  are disabled on entry to the mode-switch procedure

INT 31 P - DPMI 0.9+ - GET DPMI VERSION
	AX = 0400h
Return: CF clear
	AH = major version of DPMI spec supported
	AL = two-digit minor version of DPMI spec supported
	BX = DPMI host flags (see #03152)
	CL = processor type (02h=80286, 03h=80386, 04h=80486)
	DH = curr value of virtual master interrupt controller base interrupt
	DL = curr value of virtual slave interrupt controller base interrupt
BUG:	Windows NT versions from the March 1993 beta to at least the Final
	  release with fixes to CSD002 report version 0090h (0.144); this has
	  reportedly been corrected in the Windows NT 3.5 beta
SeeAlso: AX=0401h,INT 21/AX=250Ch,INT 2F/AX=1687h,INT 4B/AX=8102h/DX=0000h
SeeAlso: INT 67/AX=DE0Ah

Bitfields for DPMI host flags:
Bit(s)	Description	(Table 03152)
 0	running under an 80386 (32-bit) implementation
 1	processor returns to real mode for reflected interrupts instead of V86
	  mode
 2	virtual memory supported
 3	reserved (undefined)
 4-15	reserved (zero)

INT 31 P - DPMI 1.0+ - GET DPMI CAPABILITIES
	AX = 0401h
	ES:(E)DI -> 128-byte buffer for host description (see #03153)
Return: CF clear if successful
	    AX = capabilities (see #03154)
	    CX = reserved (00h)
	    DX = reserved (00h)
	    buffer filled
	CF set on error (DPMI 0.9 only)
SeeAlso: AX=0400h

Format of DPMI host description:
Offset	Size	Description	(Table 03153)
 00h	BYTE	host major version number
 01h	BYTE	host minor version number
 02h 126 BYTEs	ASCIZ host vendor name

Bitfields for DPMI capabilities:
Bit(s)	Description	(Table 03154)
 0	paged accessed/dirty supported (see AX=0506h,AX=0507h)
 1	exceptions restartability supported
 2	device mapping supported (see AX=0508h)
 3	conventional memory mapping supported (see AX=0509h)
 4	demand zero-fill supported
 5	write-protect client capability supported
 6	write-protect host capability supported
 7-15	reserved

INT 31 P - DPMI 0.9+ - GET FREE MEMORY INFORMATION
	AX = 0500h
	ES:(E)DI -> buffer for memory information (see #03155)
Return: CF clear
Notes:	16-bit programs use ES:DI, 32-bit programs use ES:EDI
	this function must be considered advisory because other applications
	  may affect the results at any time after the call
	fields not supported by the DPMI implementation are filled with
	  FFFFFFFFh
	DPMI 1.0+ supports this function solely for backward compatibility; use
	  AX=050Bh instead
	the limited DPMI host built into Phar Lap's 286|DOS-Extender v2.5 only
	  returns the first field in the memory information record
SeeAlso: AX=0501h,AX=050Bh,AX=0604h

Format of DPMI memory information:
Offset	Size	Description	(Table 03155)
 00h	DWORD	largest available block in bytes
 04h	DWORD	maximum unlocked page allocation
 08h	DWORD	maximum locked page allocation
 0Ch	DWORD	total linear address space in pages
 10h	DWORD	total unlocked pages
 14h	DWORD	free pages
 18h	DWORD	total physical pages
 1Ch	DWORD	free linear address space in pages
 20h	DWORD	size of paging file/partition in pages
 24h 12 BYTEs	reserved

INT 31 P - DPMI 0.9+ - ALLOCATE MEMORY BLOCK
	AX = 0501h
	BX:CX = size in bytes
Return: CF clear if successful
	    BX:CX = linear address of block
	    SI:DI = memory block handle for resizing and freeing block
	CF set on error
	    AX = error code (DPMI 1.0+) (8012h-8014h,8016h,8021h)(see #03143)
Notes:	no selectors are allocated
	the memory block is allocated unlocked (can be locked with AX=0600h)
	allocations are often page granular (see AX=0604h)
	under MS Windows 3.10 Enhanced mode with paging enabled, it is possible
	  for this function to fail even if AX=0500h indicates that enough
	  memory is available
SeeAlso: AX=0000h,AX=0100h,AX=0500h,AX=0502h,AX=0503h,AX=0504h,AX=0D00h
SeeAlso: INT 2F/AX=FB42h/BX=0002h

INT 31 P - DPMI 0.9+ - FREE MEMORY BLOCK
	AX = 0502h
	SI:DI = handle of memory block
Return: CF clear if successful
	CF set on error
	    AX = error code (DPMI 1.0+) (8023h) (see #03143)
Note:	any selectors allocated for the memory block must also be freed,
	  preferably before freeing the memory block
SeeAlso: AX=0001h,AX=0101h,AX=0501h,AX=0D01h

INT 31 P - DPMI 0.9+ - RESIZE MEMORY BLOCK
	AX = 0503h
	BX:CX = new size in bytes (nonzero)
	SI:DI = handle of memory block
Return: CF clear if successful
	    BX:CX = new linear address
	    SI:DI = new handle of memory block
	CF set on error
	    AX = error code (DPMI 1.0+) (8012h-8014h,8016h,8021h,8023h)
		(see #03143)
Notes:	any selectors pointing at the block must be updated
	the previous memory block handle becomes invalid
	an error is returned if the new size is 0
SeeAlso: AX=0102h,AX=0501h,AX=0505h

INT 31 P - DPMI 1.0+ - ALLOCATE LINEAR MEMORY BLOCK
	AX = 0504h
	EBX = page-aligned linear address of memory block (00000000h if any
	      address is acceptable)
	ECX = size in bytes (nonzero)
	EDX = flags
	    bit 0: set to create committed pages instead of uncommitted pages
	    bits 1-31 reserved (0)
Return: CF clear if successful
	    EBX = linear address of memory block
	    ESI = memory block handle
	CF set on error
	    AX = error code (8001h,8012h-8014h,8016h,8021h,8025h)(see #03143)
Note:	only supported by 32-bit DPMI hosts, but may be used by 16-bit clients
SeeAlso: AX=0501h,AX=0505h

INT 31 P - DPMI 1.0+ - RESIZE LINEAR MEMORY BLOCK
	AX = 0505h
	ESI = memory block handle
	ECX = new size in bytes (nonzero)
	EDX = flags
	    bit 0: create committed pages rather than uncommitted pages
	    bit 1: segment descriptor update required
		ES:EBX -> buffer containing array of WORDs with selectors
		EDI = number of selectors in array
	    bits 2-31 reserved (0)
Return: CF clear if successful
	    EBX = new linear base address
	    ESI = new memory block handle
	CF set on error
	    AX = error code (8001h,8012h-8014h,8016h,8021h,8023h)(see #03143)
Notes:	only supported by 32-bit DPMI hosts, but may be used by 16-bit clients
	the old memory block handle becomes invalid
	if EDX bit 1 set and the block's base address is changed, DPMI updates
	  all descriptors for selectors in the update buffer which fall within
	  the memory block
SeeAlso: AX=0503h,AX=0504h

INT 31 P - DPMI 1.0+ - GET PAGE ATTRIBUTES
	AX = 0506h
	ESI = memory block handle
	EBX = offset in memory block of first page
	ECX = number of pages
	ES:EDX -> array of WORDs to hold page attributes (see #03156)
Return: CF clear if successful
	    buffer filled
	CF set on error
	    AX = error code (8001h,8023h,8025h) (see #03143)
Notes:	only supported by 32-bit DPMI hosts, but may be used by 16-bit clients
	if EBX is not page-aligned, it will be rounded down
SeeAlso: AX=0504h,AX=0507h,INT 21/AX=251Dh,INT 21/AX=EB00h

Bitfields for DPMI page attribute word:
Bit(s)	Description	(Table 03156)
 0-2	page type
	000 uncommitted
	001 committed
	010 mapped (see AX=0508h,AX=0509h)
	other currently unused
 3	page is read/write rather than read-only
 4	accessed/dirty bits supplied in bits 5 and 6
 5	page has been accessed (only valid if bit 4 set)
 6	page has been written (only valid if bit 4 set)
 7-15	reserved (0)

INT 31 P - DPMI 1.0+ - MODIFY PAGE ATTRIBUTES
	AX = 0507h
	ESI = memory block handle
	EBX = offset in memory block of first page
	ECX = number of pages
	ES:EDX -> array of WORDs with new page attributes (see #03156)
Return: CF clear if successful
	CF set on error
	    AX = error code (8001h,8002h,8013h,8014h,8021h,8023h,8025h)
		(see #03143)
	    ECX = number of pages which have been set
Notes:	only supported by 32-bit DPMI hosts, but may be used by 16-bit clients
	if EBX is not page-aligned, it will be rounded down
SeeAlso: AX=0504h,AX=0506h,INT 21/AX=251Eh

INT 31 P - DPMI 1.0+ - MAP DEVICE IN MEMORY BLOCK
	AX = 0508h
	ESI = memory block handle
	EBX = page-aligned offset within memory block of page(s) to be mapped
	ECX = number of pages to map
	EDX = page-aligned physical address of device
Return: CF clear if successful
	CF set on error
	    AX = error code (8001h,8003h,8023h,8025h) (see #03143)
Notes:	only supported by 32-bit DPMI hosts, but may be used by 16-bit clients
	support of this function is optional; hosts are also allowed to support
	  the function for some devices but not others
SeeAlso: AX=0504h,AX=0509h,AX=0800h,AX=0801h

INT 31 P - DPMI 1.0+ - MAP CONVENTIONAL MEMORY IN MEMORY BLOCK
	AX = 0509h
	ESI = memory block handle
	EBX = page-aligned offset within memory block of page(s) to map
	ECX = number of pages to map
	EDX = page-aligned linear address of conventional (below 1M) memory
Return: CF clear if successful
	CF set on error
	    AX = error code (8001h,8003h,8023h,8025h) (see #03143)
Notes:	only supported by 32-bit DPMI hosts, but may be used by 16-bit clients
	support of this function is optional
SeeAlso: AX=0504h,AX=0508h,AX=0801h

INT 31 P - DPMI 1.0+ - GET MEMORY BLOCK SIZE AND BASE
	AX = 050Ah
	SI:DI = memory block handle
Return: CF clear if successful
	    SI:DI = size in bytes
	    BX:CX = base address
	CF set on error
	    AX = error code (8023h) (see #03143)
SeeAlso: AX=0501h,AX=0504h

INT 31 P - DPMI 1.0+ - GET MEMORY INFORMATION
	AX = 050Bh
	ES:(E)DI -> 128-byte buffer for memory information (see #03157)
Return: CF clear if successful
	CF set on error (DPMI 0.9 only)
Note:	16-bit programs use ES:DI, 32-bit programs must use ES:EDI
SeeAlso: AX=0500h

Format of DPMI memory information:
Offset	Size	Description	(Table 03157)
 00h	DWORD	total allocated bytes of physical memory controlled by host
 04h	DWORD	total allocated bytes of virtual memory controlled by host
 08h	DWORD	total available bytes of virtual memory controlled by host
 0Ch	DWORD	total allocated bytes of virtual memory for curr virtual mach
 10h	DWORD	total available bytes of virtual memory for curr virtual mach
 14h	DWORD	total allocated bytes of virtual memory for current client
 18h	DWORD	total available bytes of virtual memory for current client
 1Ch	DWORD	total locked bytes for current client
 20h	DWORD	maximum locked bytes for current client
 24h	DWORD	highest linear address available to current client
 28h	DWORD	largest available memory block in bytes
 2Ch	DWORD	minimum allocation unit in bytes
 30h	DWORD	allocation alignment unit size in bytes
 34h 76 BYTEs	reserved (00h)

INT 31 P - DPMI 0.9+ - LOCK LINEAR REGION
	AX = 0600h
	BX:CX = starting linear address
	SI:DI = size of region in bytes
Return: CF clear if successful
	CF set on error
	    none of the memory is locked
	    AX = error code (DPMI 1.0+) (8013h,8017h,8025h) (see #03143)
Notes:	pages at beginning and end will be locked if the region overlaps them
	may be called multiple times for a given page; the DPMI host keeps a
	  lock count for each page
SeeAlso: AX=0004h,AX=0601h,INT 21/AX=251Ah,INT 21/AX=EB06h

INT 31 P - DPMI 0.9+ - UNLOCK LINEAR REGION
	AX = 0601h
	BX:CX = starting linear address
	SI:DI = size of region in bytes
Return: CF clear if successful
	CF set on error
	    none of the memory is unlocked
	    AX = error code (DPMI 1.0+) (8002h,8025h) (see #03143)
Notes:	pages at beginning and end will be unlocked if the region overlaps them
	memory whose lock count has not reached zero remains locked
SeeAlso: AX=0005h,AX=0600h,INT 21/AX=251Bh,INT 21/AX=EB07h

INT 31 P - DPMI 0.9+ - MARK REAL MODE REGION AS PAGEABLE
	AX = 0602h
	BX:CX = starting linear address
	SI:DI = size of region in bytes
Return: CF clear if successful
	CF set on error
	    none of the memory is made pageable
	    AX = error code (DPMI 1.0+) (8002h,8025h) (see #03143)
Notes:	must relock all unlocked real mode memory before terminating process
	  for DPMI 0.9; DPMI 1.0+ automatically relocks real mode memory
	pages at beginning and end will be unlocked if the region overlaps them
	pageability of real mode pages is binary, not a count
SeeAlso: AX=0600h,AX=0603h

INT 31 P - DPMI 0.9+ - RELOCK REAL MODE REGION
	AX = 0603h
	BX:CX = starting linear address
	SI:DI = size of region in bytes
Return: CF clear if successful
	CF set on error
	    none of the memory is relocked
	    AX = error code (DPMI 1.0+) (8002h,8013h,8025h) (see #03143)
Notes:	pages at beginning and end will be relocked if the region overlaps them
	pageability of real mode pages is binary, not a count
SeeAlso: AX=0602h

INT 31 P - DPMI 0.9+ - GET PAGE SIZE
	AX = 0604h
Return: CF clear if successful
	    BX:CX = page size in bytes
	CF set on error
	    AX = error code (DPMI 1.0+) (see also #03143)
		8001h unsupported, 16-bit host
BUG:	the Borland C++ 3.1 DPMILOAD returns with CF clear but BX and CX
	  unchanged

INT 31 Pu - DPMI 0.9+ - MARK PAGES AS PAGING CANDIDATES
	AX = 0700h
	BX:CX = starting linear page number
	SI:DI = number of pages to mark as paging candidates
Return: ???
Note:	although marked as reserved in versions 0.9 and 1.0 of the DPMI
	  specification, this function is called by MS Windows TASKMAN,
	  PROGMAN, and KERNEL
SeeAlso: AX=0701h,AX=0702h

INT 31 Pu - DPMI 0.9+ - DISCARD PAGES
	AX = 0701h
	BX:CX = starting linear page number
	SI:DI = number of pages to discard
Return: ???
Note:	although marked as reserved in versions 0.9 and 1.0 of the DPMI
	  specification, this function is called by MS Windows TASKMAN,
	  PROGMAN, and KERNEL
SeeAlso: AX=0700h,AX=0703h

INT 31 P - DPMI 0.9+ - MARK PAGE AS DEMAND PAGING CANDIDATE
	AX = 0702h
	BX:CX = starting linear address
	SI:DI = number of bytes to mark as paging candidates
Return: CF clear if successful
	CF set on error
	    AX = error code (DPMI 1.0+) (8025h) (see #03143)
Notes:	this function is advisory, and does not force immediate paging
	partial pages will not be discarded
SeeAlso: AX=0700h,AX=0703h

INT 31 P - DPMI 0.9+ - DISCARD PAGE CONTENTS
	AX = 0703h
	BX:CX = starting linear address
	SI:DI = number of bytes to mark as discarded
Return: CF clear if successful
	CF set on error
	    AX = error code (DPMI 1.0+) (8025h) (see #03143)
Notes:	this function is advisory, and may be ignored by DPMI implementations
	partial pages will not be discarded
SeeAlso: AX=0701h,AX=0702h

INT 31 P - DPMI 0.9+ - PHYSICAL ADDRESS MAPPING
	AX = 0800h
	BX:CX = physical address (should be above 1 MB)
	SI:DI = size in bytes
Return: CF clear if successful
	    BX:CX = linear address which maps the requested physical memory
	CF set on error
	    AX = error code (DPMI 1.0+) (8003h,8021h) (see #03143)
Notes:	implementations may refuse this call because it can circumvent protects
	the caller must build an appropriate selector for the memory
	do not use for memory mapped in the first megabyte
SeeAlso: AX=0002h,AX=0508h,AX=0509h,AX=0801h,INT 21/AX=250Ah,INT 21/AX=EB05h

INT 31 P - DPMI 1.0+ - FREE PHYSICAL ADDRESS MAPPING
	AX = 0801h
	BX:CX = linear address returned by AX=0800h
Return: CF clear if successful
	CF set on error
	    AX = error code (8025h) (see #03143)
Note:	should be called at end of access to device mapped with AX=0800h
SeeAlso: AX=0508h,AX=0509h,AX=0800h,INT 21/AX=EB03h

INT 31 P - DPMI 0.9+ - GET AND DISABLE VIRTUAL INTERRUPT STATE
	AX = 0900h
Return: CF clear
	virtual interrupts disabled
	AL = previous interrupt state (00h disabled, 01h enabled)
	AH preserved
Notes:	the previous state may be restored simply by executing another INT 31
	a CLI instruction may be used if the previous state is unimportant,
	  but should be assumed to be very slow due to trapping by the host
SeeAlso: AX=0901h,AX=0902h

INT 31 P - DPMI 0.9+ - GET AND ENABLE VIRTUAL INTERRUPT STATE
	AX = 0901h
Return: CF clear
	virtual interrupts enabled
	AL = previous interrupt state (00h disabled, 01h enabled)
	AH preserved
Notes:	the previous state may be restored simply by executing another INT 31
	a STI instruction may be used if the previous state is unimportant,
	  but should be assumed to be very slow due to trapping by the host
SeeAlso: AX=0900h,AX=0902h

INT 31 P - DPMI 0.9+ - GET VIRTUAL INTERRUPT STATE
	AX = 0902h
Return: CF clear
	AL = current interrupt state (00h disabled, 01h enabled)
Note:	should be used rather than PUSHF because that instruction yields the
	  physical interrupt state rather than the per-client virtualized
	  interrupt flag
SeeAlso: AX=0900h,AX=0901h

INT 31 P - DPMI 0.9+ - GET VENDOR SPECIFIC API ENTRY POINT
	AX = 0A00h
	DS:(E)SI -> case-sensitive ASCIZ vendor name or identifier
Return: CF clear if successful
	    ES:(E)DI -> FAR extended API entry point
	    DS, FS, GS, EAX, EBX, ECX, EDX, ESI, EBP destroyed
	CF set on error
	    AX = error code (DPMI 1.0+) (8001h) (see #03143)
Notes:	extended API parameters are vendor-specific
	DPMI 1.0+ supports this function solely for backward compatibility; use
	  INT 2F/AX=168Ah instead
	this function is not supported by MS Windows 3.10, BC++ 3.1 DPMILOAD,
	  or QDPMI v1.0x; use INT 2F/AX=168Ah instead.	It is supported by
	  386MAX v7.01.
SeeAlso: INT 2F/AX=168Ah

INT 31 P - DPMI 0.9+ - SET DEBUG WATCHPOINT
	AX = 0B00h
	BX:CX = linear address
	DL = size (1,2,4 bytes)
	DH = type (00h execute, 01h write, 02h read/write)
Return: CF clear if successful
	    BX = watchpoint handle
	CF set on error
	    AX = error code (DPMI 1.0+) (8016h,8021h,8025h) (see #03143)
SeeAlso: AX=0212h,AX=0601h

INT 31 P - DPMI 0.9+ - CLEAR DEBUG WATCHPOINT
	AX = 0B01h
	BX = watchpoint handle
Return: CF clear if successful
	CF set on error
	    AX = error code (DPMI 1.0+) (8023h) (see #03143)
Note:	the watchpoint handle is freed
SeeAlso: AX=0B00h

INT 31 P - DPMI 0.9+ - GET STATE OF DEBUG WATCHPOINT
	AX = 0B02h
	BX = watchpoint handle
Return: CF clear if successful
	    AX = status flags
		bit 0: watch point has been executed since AX=0B00h or AX=0B03h
	CF set on error
	    AX = error code (DPMI 1.0+) (8023h) (see #03143)
SeeAlso: AX=0B00h,AX=0B03h

INT 31 P - DPMI 0.9+ - RESET DEBUG WATCHPOINT
	AX = 0B03h
	BX = watchpoint handle
Return: CF clear if successful
	CF set on error
	    AX = error code (DPMI 1.0+) (8023h) (see #03143)
SeeAlso: AX=0B02h

INT 31 P - DPMI 1.0+ - INSTALL RESIDENT HANDLER INIT CALLBACK
	AX = 0C00h
	ES:(E)DI -> resident service provider structure (see #03158)
Return: CF clear if successful
	CF set on error
	    AX = error code (8015h,8021h,8025h) (see #03143 at AX=0000h)
Note:	calling this function declares an intent to provide resident
	  protected mode services after terminating with AX=0C01h
SeeAlso: AX=0303h,AX=0C01h

Format of DPMI resident service provider structure:
Offset	Size	Description	(Table 03158)
 00h	QWORD	descriptor for 16-bit data segment
 08h	QWORD	descriptor for 16-bit code segment (zeros if not supported)
 10h	WORD	offset of 16-bit callback procedure
 12h  2 BYTEs	reserved
 14h	QWORD	descriptor for 32-bit data segment
 1Ch	QWORD	descriptor for 32-bit code segment (zeros if not supported)
 24h	DWORD	offset of 32-bit callback procedure

INT 31 P - DPMI 1.0+ - TERMINATE AND STAY RESIDENT
	AX = 0C01h
	BL = return code
	DX = number of paragraphs of DOS memory to reserve (0 or >= 6)
Return: never
Notes:	should only be used if the program will only provide services to
	  other DPMI programs
	any protected mode memory remains allocated to the program unless
	  explicitly freed before this call
	must first call AX=0C00h or program will simply be terminated
SeeAlso: AX=0C00h,INT 21/AH=31h

INT 31 P - DPMI 1.0+ - ALLOCATE SHARED MEMORY
	AX = 0D00h
	ES:(E)DI -> shared memory allocation request structure (see #03159)
Return: CF clear if successful
	    request structure updated
	CF set on error
	    AX = error code (8012h,8013h,8014h,8016h,8021h) (see #03143)
Note:	first 16 bytes of memory block will be initialized to zeros on the
	  first allocation
SeeAlso: AX=0501h,AX=0D01h,AX=0D02h

Format of DPMI shared memory allocation request structure:
Offset	Size	Description	(Table 03159)
 00h	DWORD	requested length of shared memory block in bytes
 04h	DWORD	(ret) allocated length of block
 08h	DWORD	(ret) shared memory handle
 0Ch	DWORD	(ret) linear address of memory block
 10h	PWORD	selector:offset32 of ASCIZ name for memory block
		(name max 128 bytes)
 16h  2 BYTEs	reserved
 18h  4 BYTEs	reserved (00h)

INT 31 P - DPMI 1.0+ - FREE SHARED MEMORY
	AX = 0D01h
	SI:DI = shared memory block handle
Return: CF clear if successful
	CF set on error
	    AX = error code (8023h) (see #03143)
Notes:	handle becomes invalid after this call
	DPMI maintains separate global and virtual machine use counts for each
	  shared memory block; when the global use counts reaches zero, the
	  block is finally destroyed
SeeAlso: AX=0502h,AX=0D00h

INT 31 P - DPMI 1.0+ - SERIALIZE SHARED MEMORY
	AX = 0D02h
	SI:DI = shared memory block handle
	DX = flags
	    bit 0: return immediately rather than suspending if serialization
		  unavailable
	    bit 1: shared rather than exclusive serialization
	    bits 2-15 reserved (0)
Return: CF clear if successful
	CF set on error
	    AX = error code (8004h,8005h,8017h-8019h,8023h) (see #03143)
Notes:	an exclusive serialization blocks any other serialization attempts for
	  the same block by another virtual machine; a shared serialization
	  blocks attempts at exclusive serialization by another virtual machine
	hosts are not required to detect deadlock
	a client's interrupt handler can cancel a serialization call which
	  caused it to block by calling AX=0D03h
SeeAlso: AX=0D00h,AX=0D03h

INT 31 P - DPMI 1.0+ - FREE SERIALIZATION ON SHARED MEMORY
	AX = 0D03h
	SI:DI = shared memory block handle
	DX = flags
	    bit 0: release shared serialization rather than exclusive serialztn
	    bit 1: free pending serialization
	    bits 2-15 reserved (0)
Return: CF clear if successful
	CF set on error
	    AX = error code (8002h,8023h) (see #03143 at AX=0000h)
SeeAlso: AX=0D00h,AX=0D02h

INT 31 P - DPMI 1.0+ - GET COPROCESSOR STATUS
	AX = 0E00h
Return: CF clear
	AX = coprocessor status (see #03160)
Note:	supported by 386MAX v6.01, which otherwise only supports DPMI 0.9
SeeAlso: AX=0E01h

Bitfields for DPMI coprocessor status:
Bit(s)	Description	(Table 03160)
 0	numeric coprocessor enabled for current client
 1	client is emulating coprocessor
 2	numeric coprocessor is present
 3	host is emulating coprocessor instructions
 4-7	coprocessor type
	0000 none
	0010 80287
	0011 80387
	0100 80486 with numeric coprocessor
	other reserved
 8-15	not used

INT 31 P - DPMI 1.0+ - SET EMULATION
	AX = 0E01h
	BX = coprocessor flag bits (see #03161)
Return: CF clear if successful
	CF set on error
	    AX = error code (8026h) (see #03143 at AX=0000h)
Note:	supported by 386MAX v6.01, which otherwise only supports DPMI 0.9
SeeAlso: AX=0E00h

Bitfields for DPMI coprocessor flags:
Bit(s)	Description	(Table 03161)
 0	enable numeric coprocessor for current client
 1	client will emulate coprocessor
 2-15	not used

INT 31 - Netroom3 DPMI.EXE v3.00 - ???
	AH = 57h
	AL = subfunction (at least 02h,03h,04h,05h,07h,08h,09h,0Ah)
	???
Return: ???
SeeAlso: INT 2C/AX=0000h"Cloaking"

INT 31 - Netroom3 DPMI.EXE v3.00 - SWITCH TO PROTECTED MODE
	AX = 5702h
	DX = PSP segment of caller
	STACK: WORD	???
	       WORD	flags (bit 0 set if 32-bit program)
Return: as for DPMI mode-switch entry point (see #02718 at INT 2F/AX=1687h)
Note:	this function is called by the real-mode DPMI mode-switch entry point
SeeAlso: INT 2F/AX=1687h

INT 31 - DOS32 v3.0+ - GET DOS32 VERSION AND SELECTOR VALUES
	AX = EE00h
Return: AL = minor version (BCD)
	AH = major version (BCD)
	DL = system type (1=raw DOS, 2=XMS, 4=VCPI, 8=DPMI)
	BX = selector of 4GB data segment with zero base address
Program: DOS32 is a 32 bit DOS extender by Adam Seychell.
SeeAlso: AX=EE02h

INT 31 - DOS32 v3.0+ - GET DOS32 ADDRESS INFORMATION
	AX = EE02h
Return: AX = real-mode segment of temporary 8K buffer (v3.1+)
	EBX = 32bit linear address of the program segment
	EDX = Total size in bytes of the programs .EXE file after linking.
	ESI = offset address of PSP
	EDI = offset address of program environment
	ECX = offset address of the program's .EXE ASCIZ file name and path
SeeAlso: AX=EE00h,AX=EE20h

INT 31 - DOS32 v3.2+ - SET UP A DOS32 LOADABLE LIBRARY
	AX = EE10h
	EDX -> library ASCIZ path\filename
	EBX = number of bytes to seek from beginning of file
Return: CF clear if successful
	    EAX = size of memory block required to store library
	    EBX = size of library file
	CF set on error
	    AL = error code.
		01h error opening or reading file
		02h bad DOS32 library file
SeeAlso: AX=EE00h,AX=EE11h

INT 31 - DOS32 v3.2+ - LOAD LIBRARY FILE
	AX = EE11h
	EDX -> near pointer of memory block to store library
Return: CF clear if successful
	    EDX = near pointer to the dynamic library public
	CF set on error
Note:	must first successfuly call function AX=EE10h before calling this
	  function
SeeAlso: AX=EE00h,AX=EE10h

INT 31 - DOS32 v3.0+ - GET REAL MODE CALL BACK ADDRESS WITH RETF STACK FRAME
	AX = EE20h
	ESI = offset of the real mode call back function
Return: CF clear if successful
	    CX:DX = real mode address to call up to the protected mode
		  procedure
	CF set on error
SeeAlso: AX=EE00h,AX=EE02h,AX=EE21h

INT 31 - DOS32 v3.0+ - GET REAL MODE CALL BACK ADDRESS WITH IRET STACK FRAME
	AX = EE21h
	ESI = offset of the real mode call back function
Return: CF clear if successful
	    CX:DX = real mode address to call up to the protected mode
		  procedure
	CF set on error
SeeAlso: AX=EE20h

INT 31 - DOS32 v3.0+ - TERMINATE AND STAY RESIDENT
	AX = EE30h
SeeAlso: AX=EE21h,AX=EE40h,INT 21/AH=31h

INT 31 - DOS32 v3.0+ - UNDO PREVIOUS MEMORY ALLOCATION or DMA BUFFER
	AX = EE40h
Return: CF clear if successful
	CF set on error
SeeAlso: AX=EE41h,AX=EE42h

INT 31 - DOS32 v3.0+ - ALLOCATE 16KB DMA BLOCK
	AX = EE41h
Return: CF clear if successful
	    EBX -> 16KB DMA block (physical address)
	    EDX -> 16KB DMA block (offset address)
	CF set on error
SeeAlso: AX=EE40h,AX=EE42h

INT 31 - DOS32 v3.0+ - ALLOCATE MEMORY BLOCK
	AX = EE42h
	EDX = size in bytes
Return: CF clear if successful
	    EAX = size in bytes
	    EDX -> memory block
	CF set on error
Note:	size is rounded off to the next 4KB boundary
SeeAlso: AX=EE40h,AX=EE41h

INT 31 P - CauseWay - "Info" - GET SYSTEM SELECTORS/FLAGS
	AX = FF00h
Return: AX = selector for flag address space (base 00000000h, limit 4GB)
	BX = selector for current PSP segment (limit 0100h)
	(E)CX = size of DOS transfer buffer (max 64K)
	DX = real-mode segment address of DOS transfer buffer
	ES:(E)SI = protected-mode address of DOS transfer buffer
	EDI = system flags (see #03162)
Program: CauseWay is a 386 DOS extender by Michael Devore and John Wildsmith
	  for use with Watcom C++ or assembly language programs
Notes:	the entire transfer buffer can be addressed with a 16-bit offset in
	  protected mode
	CauseWay always maps selector 0040h to the BIOS data segment at
	  real-mode segment 0040h; when not running under a DPMI host, CauseWay
	  also provides selectors A000h, B000h, and B800h mapped to video
	  memory
SeeAlso: AX=FF25h

Bitfields for CauseWay system flags:
Bit(s)	Description	(Table 03162)
 0	32-bit code
 1	virtual memory manage enabled
 3-2	mode: 00 raw extended memory, 01 VCPI, 10 DPMI
 4	DPMI available
 5	VCPI available
 6	no memory managers
 7	application descriptor table type: 0 = GDT, 1 = LDT
 14-8	reserved
 15	debugging engine present

INT 31 P - CauseWay - "IntXX" - SIMULATE REAL-MODE INTERRUPT
	AX = FF01h
	BL = interrupt number
	ES:(E)DI -> real-mode register list (see #03148 at AX=0300h)
Return: register list updated
Note:	CauseWay fills in the values for SS, SP, and FLAGS itself, and ignores
	  the values specified for CS and IP
SeeAlso: AX=0300h,AX=FF02h

INT 31 P - CauseWay - "FarCallReal" - SIMULATE REAL-MODE FAR CALL
	AX = FF02h
	ES:(E)DI -> real-mode register list (see #03148 at AX=0300h)
Return: register list updated
SeeAlso: AX=0301h,AX=FF01h

INT 31 P - CauseWay - "GetSel" - ALLOCATE NEW SELECTOR
	AX = FF03h
Return: CF clear if successful
	    BX = new selector
	CF set on error
Note:	the new selector is initialized with a base address of 000000h, a limit
	  of 0000h, and attributes read/write expand-up data
SeeAlso: AX=FF04h,AX=FF05h,AX=FF06h

INT 31 P - CauseWay - "RelSel" - RELEASE A SELECTOR
	AX = FF04h
	BX = selector
Return: CF clear if successful
	CF set on error
SeeAlso: AX=FF03h,AX=FF06h

INT 31 P - CauseWay - "CodeSel" - CONVERT SELECTOR TO EXECUTABLE CODE SELECTOR
	AX = FF05h
	BX = selector
	CL = default operation size (00h = 16-bit, 01h = 32-bit)
Return: CF clear if successful
	CF set on error
SeeAlso: AX=FF03h

INT 31 P - CauseWay - "AliasSel" - CREATE READ/WRITE DATA ALIAS SELECTOR
	AX = FF06h
	BX = original selector
Return: CF clear if successful
	    AX = new data selector aliasing original selector
	CF set on error
SeeAlso: AX=FF03h,AX=FF04h

INT 31 P - CauseWay - "GetSelDet" - GET SELECTOR BASE AND LIMIT
	AX = FF07h
	BX = selector
Return: CF clear if successful
	    CX:DX = base address
	    SI:DI = limit (bytes)
	CF set on error
SeeAlso: AX=FF08h,AX=FF09h

INT 31 P - CauseWay - "GetSelDet32" - GET SELECTOR BASE AND LIMIT (32-bit)
	AX = FF08h
Return: CF clear if successful
	    EDX = base address
	    ECX = limit (bytes)
	CF set on error
SeeAlso: AX=FF07h,AX=FF0Ah

INT 31 P - CauseWay - "SetSelDet" - SET SELECTOR BASE AND LIMIT
	AX = FF09h
	BX = selector
	CX:DX = new base address
	SI:DI = new byte-granular limit
Return: CF clear if successful
	CF set on error
SeeAlso: AX=FF07h,AX=FF0Ah

INT 31 P - CauseWay - "SetSelDet32" - SET SELECTOR BASE AND LIMIT (32-bit)
	AX = FF0Ah
	BX = selector
	EDX = new base address
	ECX = new byte-granular limit
Return: CF clear if successful
	CF set on error
SeeAlso: AX=FF08h,AX=FF09h

INT 31 P - CauseWay - "GetMem" - ALLOCATE BLOCK OF MEMORY
	AX = FF0Bh
	CX:DX = size in bytes (FFFFh:FFFFh to get size of largest available)
Return: CF clear if successful
	    BX = selector for accessing block if requested size not FFFFh:FFFFh
	    CX:DX = size of largest available block if requested FFFFh:FFFFh
	CF set on error
SeeAlso: AX=FF0Ch,AX=FF0Dh,AX=FF0Fh,AX=FF10h,AX=FF2Ch

INT 31 P - CauseWay - "GetMem32" - ALLOCATE BLOCK OF MEMORY (32-bit)
	AX = FF0Ch
	ECX = size in bytes (FFFFFFFFh to get size of largest available block)
Return: CF clear if successful
	    BX = selector for accessing block if requested size not FFFFh:FFFFh
	    ECX = size of largest available block if requested FFFFh:FFFFh
	CF set on error
SeeAlso: AX=FF0Bh,AX=FF0Eh,AX=FF0Fh,AX=FF11h

INT 31 P - CauseWay - "ResMem" - RESIZE MEMORY BLOCK
	AX = FF0Dh
	BX = selector for block to be resized
	CX:DX = new size in bytes
Return: CF clear if successful
	CF set on error
Note:	the memory block may have to be copied to another location in order
	  to satisfy the requested new size, in which case the base address
	  of the selector is updated
SeeAlso: AX=FF0Bh,AX=FF0Eh,AX=FF12h

INT 31 P - CauseWay - "ResMem32" - RESIZE MEMORY BLOCK (32-bit)
	AX = FF0Eh
	BX = selector for block to be resized
	ECX = new size in bytes
Return: CF clear if successful
	CF set on error
Note:	the memory block may have to be copied to another location in order
	  to satisfy the requested new size, in which case the base address
	  of the selector is updated
SeeAlso: AX=FF0Ch,AX=FF0Dh,AX=FF13h

INT 31 P - CauseWay - "RelMem" - RELEASE PREVIOUSLY ALLOCATED MEMORY
	AX = FF0Fh
	BX = selector for block to be released
Return: CF clear if successful
	CF set on error
SeeAlso: AX=FF0Bh,AX=FF0Ch,AX=FF14h

INT 31 P - CauseWay - "GetMemLinear" - ALLOCATE MEMORY WITHOUT SELECTOR
	AX = FF10h
	CX:DX = size of block in bytes
Return: CF clear if successful
	    SI:DI = linear address of allocated block
	CF set on error
Note:	this function may return addresses above 16M
SeeAlso: AX=FF0Bh,AX=FF11h,AX=FF12h,AX=FF14h

INT 31 P - CauseWay - "GetMemLinear32" - ALLOCATE MEMORY WITHOUT SELECTOR
	AX = FF11h
	ECX = size of block in bytes
Return: CF clear if successful
	    ESI = linear address of allocated block
	CF set on error
Note:	this function may return addresses above 16M
SeeAlso: AX=FF0Ch,AX=FF10h,AX=FF13h,AX=FF14h

INT 31 P - CauseWay - "ResMemLinear" - RESIZE LINEAR MEMORY BLOCK
	AX = FF12h
	CX:DX = new size in bytes
	SI:DI = linear address of block to be resized
Return: CF clear if successful
	   SI:DI = new linear address of block
	CF set on error
SeeAlso: AX=FF0Dh,AX=FF10h,AX=FF13h

INT 31 P - CauseWay - "ResMemLinear32" - RESIZE LINEAR MEMORY BLOCK (32-bit)
	AX = FF13h
	ECX = new size in bytes
	ESI = linear address of block to be resized
Return: CF clear if successful
	   ESI = new linear address of block
	CF set on error
SeeAlso: AX=FF0Eh,AX=FF11h,AX=FF12h

INT 31 P - CauseWay - "RelMemLinear" - RELEASE LINEAR MEMORY BLOCK
	AX = FF14h
	SI:DI = linear address of block to be released
Return: CF clear if successful
	CF set on error
SeeAlso: AX=FF0Fh,AX=FF10h,AX=FF15h

INT 31 P - CauseWay - "RelMemLinear32" - RELEASE LINEAR MEMORY BLOCK (32-bit)
	AX = FF15h
	ESI = linear address of block to be released
Return: CF clear if successful
	CF set on error
SeeAlso: AX=FF0Fh,AX=FF11h,AX=FF15h

INT 31 P - CauseWay - "GetMemNear" - ALLOCATE APPLICATION-RELATIVE MEMORY
	AX = FF16h
	EBX = size in bytes of block to allocate
Return: CF clear if successful
	   ESI = application-relative linear address of allocated block
	CF set on error
SeeAlso: AX=FF17h,AX=FF18h,AX=FF19h

INT 31 P - CauseWay - "ResMemNear" - RESIZE APPLICATION-RELATIVE MEMORY BLOCK
	AX = FF17h
	EBX = size in bytes of block to allocate
	ESI = application-relative linear address of block
Return: CF clear if successful
	    ESI = new application-relative linear address of block
	CF set on error
SeeAlso: AX=FF16h,AX=FF18h,AX=FF19h

INT 31 P - CauseWay - "RelMemNear" - RELEASE APPLICATION-RELATIVE MEMORY BLOCK
	AX = FF18h
	ESI = application-relative linear address of block
Return: CF clear if successful
	CF set on error
SeeAlso: AX=FF16h,AX=FF17h,AX=FF19h

INT 31 P - CauseWay - "Linear2Near" - CONVERT LINEAR TO APP-RELATIVE ADDRESS
	AX = FF19h
	ESI = linear address
Return: ESI = application-relative linear address
SeeAlso: AX=FF1Ah

INT 31 P - CauseWay - "Near2Linear" - CONVERT APP-RELATIVE TO LINEAR ADDRESS
	AX = FF1Ah
	ESI = application-relative linear address
Return: ESI = linear address
SeeAlso: AX=FF19h

INT 31 P - CauseWay - "LockMem" - LOCK REGION OF MEMORY
	AX = FF1Bh
	BX:CX = starting linear address
	SI:DI = size of region in bytes
Return: CF clear if successful
	CF set on error
Desc:	prevent memory from being swapped out by the virtual memory manager
Note:	locks are applied on 4K page boundaries, so memory above and below
	  the specified region may be locked as well
SeeAlso: AX=FF1Ch,AX=FF1Dh

INT 31 P - CauseWay - "LockMem32" - LOCK REGION OF MEMORY (32-bit)
	AX = FF1Ch
	ESI = starting linear address
	ECX = size of region in bytes
Return: CF clear if successful
	CF set on error
Desc:	prevent memory from being swapped out by the virtual memory manager
Note:	locks are applied on 4K page boundaries, so memory above and below
	  the specified region may be locked as well
SeeAlso: AX=FF1Bh,AX=FF1Eh,AX=FF1Fh

INT 31 P - CauseWay - "UnLockMem" - UNLOCK REGION OF MEMORY
	AX = FF1Dh
	BX:CX = starting linear address
	SI:DI = size of region in bytes
Return: CF clear if successful
	CF set on error
Desc:	allow memory to be swapped out by the virtual memory manager
Note:	locks are applied on 4K page boundaries, so memory above and below
	  the specified region may be unlocked as well
SeeAlso: AX=FF1Bh,AX=FF1Eh

INT 31 P - CauseWay - "UnLockMem32" - UNLOCK REGION OF MEMORY (32-bit)
	AX = FF1Eh
	ESI = starting linear address
	ECX = size of region in bytes
Return: CF clear if successful
	CF set on error
Desc:	allow memory to be swapped out by the virtual memory manager
Note:	locks are applied on 4K page boundaries, so memory above and below
	  the specified region may be unlocked as well
SeeAlso: AX=FF1Ch,AX=FF1Dh,AX=FF20h

INT 31 P - CauseWay - "LockMemNear" - LOCK APPLICATION-RELATIVE MEMORY REGION
	AX = FF1Fh
	ESI = starting application-relative linear address
	EBX = size of region in bytes
Return: CF clear if successful
	CF set on error
Desc:	prevent memory from being swapped out by the virtual memory manager
Note:	locks are applied on 4K page boundaries, so memory above and below
	  the specified region may be locked as well
SeeAlso: AX=FF1Ch,AX=FF20h

INT 31 P - CauseWay - "UnLockMemNear" - UNLOCK APP-RELATIVE MEMORY REGION
	AX = FF20h
	ESI = starting application-relative linear address
	ECX = size of region in bytes
Return: CF clear if successful
	CF set on error
Desc:	allow memory to be swapped out by the virtual memory manager
Note:	locks are applied on 4K page boundaries, so memory above and below
	  the specified region may be unlocked as well
SeeAlso: AX=FF1Eh,AX=FF1Fh

INT 31 P - CauseWay - "GetMemDOS" - ALLOCATE CONVENTIONAL MEMORY
	AX = FF21h
	BX = number of paragraphs to allocate
Return: CF clear if successful
	    AX = real-mode segment of allocated block
	    DX = initial selector for block
	CF set on error
	    AX = DOS error code (see #01680 at INT 21/AH=59h/BX=0000h)
	    BX = size of largest available block
Note:	if the requested size is greater than 64K, contiguous selectors will
	  be allocated, one for each 64K; for 32-bit applications, the first
	  selector's limit will be set to the size of the entire block, while
	  that selector will have a limit of 64K for 16-bit applications.  All
	  selectors after the first one have a limit of 64K except the final
	  one
SeeAlso: AX=FF22h,AX=FF23h,INT 21/AH=48h

INT 31 P - CauseWay - "ResMemDOS" - RESIZE CONVENTIONAL MEMORY BLOCK
	AX = FF22h
	BX = new size in paragraphs
	DX = initial selector for block
Return: CF clear if successful
	CF set on error
	    AX = DOS error code (see #01680 at INT 21/AH=59h/BX=0000h)
	    BX = maximum number of paragraphs available
Note:	this function will also fail if the block is expanded past a 64K
	  boundary and the next selector is already in use
SeeAlso: AX=FF21h,AX=FF23h,INT 21/AH=49h

INT 31 P - CauseWay - "RelMemDOS" - RELEASE CONVENTIONAL MEMORY BLOCK
	AX = FF23h
	DX = initial selector for block
Return: CF clear if successful
	CF set on error
	    AX = DOS error code (see #01680 at INT 21/AH=59h/BX=0000h)
Note:	all descriptors allocated for the block are freed
SeeAlso: AX=FF21h,AX=FF22h,INT 21/AH=4Ah

INT 31 P - CauseWay - "ExecOverlay" - LOAD AND OPTIONALLY EXECUTE APP CODE
	AX = FF24h
	EBX = flags
	    bit 0: don't execute (overlay only)
	    bit 1: don't preserve relocation information
	ES:EDX -> filename (see also #03163)
	FS:ESI -> commandline (ESI = 00000000h if no commandline)
	GS:EDI -> name (CW's /o option)
Return: CF clear if successful
	    ---EBX bit 0 set---
	    CX:EDX = program entry point (CS:EIP)
	    SI = segment of PSP
	    ---EBX bit 1 set---
	    BX:EAX = initial SS:ESP
	    EDI high word = base segment
	    EDI low word = number of segments
	    EBP = start of segment definitions
	CF set on error
	    AX = error code
		0001h DOS file access error
		0002h not a CuaseWay 3P file
		0003h not enough memory
SeeAlso: AX=FF2Ah,INT 21/AH=4Bh

Format of CauseWay executable:
Offset	Size	Description	(Table 03163)
 00h  2 BYTEs	signature "3P"
 02h	DWORD	size of header data in bytes
 06h	DWORD	size of EXE image data in bytes
 0Ah	DWORD	number of bytes of program memory required
 0Eh	WORD	number of segment definitions (see #03165)
 10h	DWORD	number of relocation table entries
 14h	DWORD	offset of program entry point
 18h	WORD	segment list entry number for entry point's CS
 1Ah	DWORD	initial ESP
 1Eh	WORD	segment list entry number for initial SS
 20h	DWORD	control flags (see #03164)
 24h	DWORD	automatic stack size in bytes if ESP entry = 00000000h
 28h	BYTE	length of name (name follows program image)
 29h 23 BYTEs	reserved
SeeAlso: #01594,#01609 at INT 21/AH=4Bh

Bitfields for CauseWay executable control flags:
Bit(s)	Description	(Table 03164)
 0	16-bit interrupt stack frame
 7	descriptor table type (0 = GDT, 1 = LDT)
 14	16-bit default data size
 31	compressed EXE image
Note:	bits 0 and 14 should always be equal
SeeAlso: #03163

Format of CauseWay segment definition [array]:
Offset	Size	Description	(Table 03165)
 00h	DWORD	start offset within program image
 04h	DWORD	length and type
		bits 0-19: length
		bit 20:	   granularity (if set, length is in 4K pages)
		bits 21-24: type
			0000 code
			0001 read/write data
			0010 stack
			0011 read-only data
		bit 25: force segment descriptor's D bit to 0
		bit 26: force segmetn descriptor's D bit to 1
SeeAlso: #03163

INT 31 P - CauseWay - "GetDOSTrans" - GET DOS TRANSFER BUFFER
	AX = FF25h
Return: BX = real-mode segment of transfer buffer
	ECX = transfer buffer size
	DX = protected-mode selector for transfer buffer
Note:	the default buffer size of 8K is sufficient for most applications,
	  but an application performing large amounts of file I/O may benefit
	  from allocating its own, larger buffer
SeeAlso: AX=FF00h,AX=FF26h

INT 31 P - CauseWay - "SetDOSTrans" - SET DOS TRANSFER BUFFER
	AX = FF26h
	BX = real-mode segment of new transfer buffer
	ECX = new transfer buffer size
	DX = protected-mode selector for new transfer buffer
Return: nothing
Note:	the specific buffer must be located in conventional memory; only the
	  first 64K will be used
SeeAlso: AX=FF25h

INT 31 P - CauseWay v1.3 - "GetMCBSize" - GET CURRENT MCB ALLOCATION BLOCK SIZE
	AX = FF27h
Return: ECX = current threshold
Desc:	determine the memory allocation size below which CauseWay will use
	  internal MCB chains rather than allocating full 4K pages via DPMI
SeeAlso: AX=FF00h,AX=FF28h

INT 31 P - CauseWay v1.3 - "SetMCBSize" - SET MCB MEMORY ALLOCATION BLOCK SIZE
	AX = FF28h
	ECX = new threshold (0000000h to disable MCB memory allocation system)
Return: CF clear if successful
	    threshold unchanged (default 16K)
	CF set on error (threshold > 64K)
Desc:	specify the memory allocation size below which CauseWay will use
	  internal MCB chains rather than allocating full 4K pages via DPMI
Note:	the specified threshold will be rounded up to the next higher multiple
	  of 4K
SeeAlso: AX=FF00h,AX=FF27h

INT 31 P - CauseWay v1.3 - "GetSels" - ALLOCATE MULTIPLE SELECTORS
	AX = FF29h
	CX = number of selectors to allocate
Return: BX = base selector
Desc:	allocate multiple contiguous selectors, initializing each to have a
	  base address and limit of zero
SeeAlso: AX=FF00h,AX=FF04h

INT 31 P - CauseWay v1.3 - "cwLoad" - LOAD ANOTHER CAUSEWAY PROGRAM AS OVERLAY
	AX = FF2Ah
	DS:EDX -> filename
Return: CF clear if successful
	    CX:EDX = CS:EIP of entry point
	    BX:EAX = initial SS:ESP for program
	    SI = PSP for overlay program
	CF set on error
	    AX = error code (01h file error, 02h not a 3P file, 03h no memory)
Note:	the returned PSP can be given to "RelMem" (AX=FF0Fh) to release the
	  overlay's memory and selectors; only selectors and memory allocated
	  during loading will be freed by RelMem unless one switches PSPs with
	  INT 21/AH=50h
SeeAlso: AX=FF00h,AX=FF24h

INT 31 P - CauseWay v1.3 - "cwcInfo" - VALIDATE AND GET SIZE OF CWC FILE
	AX = FF2Bh
	BX = file handle for CWC-compressed file
Return: CF clear if successful
	    ECX = expanded file size
	CF set on error (not a CWC-compressed file)
SeeAlso: AX=FF00h,AX=FFFBh

INT 31 P - CauseWay v1.3 - "GetMemSO" - ALLOCATE MEMORY AND RETURN SEL:OFFSET
	AX = FF2Ch
	CX:DX = block size in bytes
Return: CF clear if successful
	   SI:DI = selector:offset of allocated memory
	CF set on error
Note:	unlike "GetMem" (AX=FF0Bh), this function will reuse selectors until a
	  segment is full, rather than allocating a new selector for each
	  memory block
SeeAlso: AX=FF00h,AX=FF2Dh,AX=FF2Eh

INT 31 P - CauseWay v1.3 - "ResMemSO" - RESIZE SELECTOR:OFFSET MEMORY BLOCK
	AX = FF2Dh
	SI:DI = selector:offset for memory block
	CX:DX = new size of block
Return: CF clear if successful
	   SI:DI = new selector:offset for memory block
	CF set on error
SeeAlso: AX=FF00h,AX=FF2Ch,AX=FF2Eh

INT 31 P - CauseWay v1.3 - "RelMemSO" - RELEASE SELECTOR:OFFSET MEMORY BLOCK
	AX = FF2Eh
	SI:DI = selector:offset for memory block
SeeAlso: AX=FF00h

INT 31 P - Causeway v1.3 - "cwcLoad" - LOAD/EXPAND CWC-COMPRESSED FILE
	AX = FFFBh
	BX = source file handle
	ES:EDI -> memory buffer into which to expand file
Return: CF clear if successful
	    ECX = expanded data length
	CF set on error
	    EAX = error code (01h file error, 02h bad data, 03h not CWC file)
Note:	the provided file may consist of the concatenation of several CWC
	  files; the one beginning at the current file position will be
	  expanded
SeeAlso: AX=FF2Bh