Specifications

D:\D\inter61a\INTERRUP.A Saturday, January 08, 2011 11:31 AM

SeeAlso: INT 0B"HP 95LX",INT 15/AX=4DD4h,INT 15/AH=4Eh

--------V-06---------------------------------

INT 06 U - no-name clone - GRAPHICS CHARACTER TABLE (NOT A VECTOR!)

Desc: points at graphics data for characters 00h-7Fh of the current font

SeeAlso: INT 43"EGA",INT 44"VIDEO"

--------C-07---------------------------------

INT 07 C - CPU-generated (80286+) - PROCESSOR EXTENSION NOT AVAILABLE

Desc: this interrupt is automatically called if a coprocessor instruction is

encountered when no coprocessor is installed

Note: can be used to emulate a numeric coprocessor in software

SeeAlso: INT 09"CPU"

--------H-08---------------------------------

INT 08 C - IRQ0 - SYSTEM TIMER

Desc: generated 18.2 times per second by channel 0 of the 8254 system timer,

this interrupt is used to keep the time-of-day clock updated

Notes: programs which need to be invoked regularly should use INT 1C unless

they need to reprogram the timer while still keeping the time-of-day

clock running at the proper rate

default handler is at F000h:FEA5h in IBM PC and 100%-compatible BIOSes

may be masked by setting bit 0 on I/O port 21h

SeeAlso: INT 1C,INT 4A"SYSTEM",INT 50"DESQview",INT 58"DoubleDOS",INT 70"IRQ8"

SeeAlso: INT 78"GO32",INT D8"Screen Thief",MEM 0040h:0040h,MEM 0040h:006Ch

--------C-08---------------------------------

INT 08 C - CPU-generated (80286+) - DOUBLE EXCEPTION DETECTED

Desc: called when multiple exceptions occur on one instruction, or an

exception occurs in an exception handler

Notes: called in protected mode if an interrupt above the defined limit of

the interrupt vector table occurs

return address points at beginning of instruction with errors or the

beginning of the instruction which was about to execute when the

external interrupt caused the exception

if an exception occurs in the double fault handler, the CPU goes into

SHUTDOWN mode (which circuitry in the PC/AT converts to a reset);

this "triple fault" is a faster way of returning to real mode on

many 80286 machines than the standard keyboard controller reset

--------H-09---------------------------------

INT 09 C - IRQ1 - KEYBOARD DATA READY

Desc: this interrupt is generated when data is received from the keyboard.

This is normally a scan code (from either a keypress *or* a key

release), but may also be an ACK or NAK of a command on AT-class

keyboards.

-15-

http://www.foxitsoftware.com For evaluation only.