Index for interrupt INT 0B
Table of Contents by Order
0B - INT 0B C - IRQ3 - SERIAL COMMUNICATIONS (COM2)
0B - INT 0B CP - CPU-generated (80286+) - SEGMENT NOT PRESENT
0B - INT 0B - HP 95LX - LOW-LEVEL KEYBOARD HANDLER
INT 0B C - IRQ3 - SERIAL COMMUNICATIONS (COM2) Desc: automatically asserted by the UART when COM2 needs attention, if the UART has been programmed to generate interrupts Notes: the TOPS and PCnet adapters use this interrupt request line as an alternate on PS/2s, COM2 through COM8 share this interrupt; on many PC's, COM4 shares this interrupt may be masked by setting bit 3 on I/O port 21h DOS 3.3+ revectors IRQ3 to a stack-switching routine unless STACKS=0 has been set in CONFIG.SYS. MS/PC-DOS use the IBM Interrupt Sharing Protocol (see #02568) when hooking this IRQ SeeAlso: INT 0C"COM1",INT 53"DESQview",INT 5B"DoubleDOS",INT 7B"GO32"Top
INT 0B CP - CPU-generated (80286+) - SEGMENT NOT PRESENT Desc: generated when loading a segment register if the segment descriptor indicates that the segment is not currently in memory, unless the segment is an LDT (see INT 0A"CPU") or stack segment (see INT 0C"CPU") needed by a task switch Note: may be used to implement virtual memory by loading in segments as they are accessed, clearing the "not present" bit after loading SeeAlso: INT 0A"CPU",INT 0E"CPU"Top
INT 0B - HP 95LX - LOW-LEVEL KEYBOARD HANDLER Desc: this is the lowest-level keyboard handler on an HP 95LX palmtop Note: debounces key, places the keycode in I/O register 60h, and calls INT 09 SeeAlso: INT 09,INT 0D"HP 95LX",INT 15/AX=4DD4hTop