Real Mode IVT Map

The following is a list of the standard BIOS interrupts used in a typical BIOS.

 

Interrupt	Address	Type	Description
00h	0000:0000h	Processor	Divide by zero
01h	0000:0004h	Processor	Single step
02h	0000:0008h	Processor	Non maskable interrupt (NMI)
03h	0000:000Ch	Processor	Breakpoint
04h	0000:0010h	Processor	Arithmetic overflow
05h	0000:0014h	Software	Print screen
06h	0000:0018h	Processor	Invalid op code
07h	0000:001Ch	Processor	Coprocessor not available
08h	0000:0020h	Hardware	System timer service routine
09h	0000:0024h	Hardware	Keyboard device service routine
0Ah	0000:0028h	Hardware	Cascade from 2nd programmable interrupt controller
0Bh	0000:002Ch	Hardware	Serial port service - COM post 2
0Ch	0000:0030h	Hardware	Serial port service - COM port 1
0Dh	0000:0034h	Hardware	Parallel printer service - LPT 2
0Eh	0000:0038h	Hardware	Floppy disk service
0Fh	0000:003Ch	Hardware	Parallel printer service - LPT 1
10h	0000:0040h	Software	Video service routine
11h	0000:0044h	Software	Equipment list service routine
12h	0000:0048H	Software	Memory size service routine
13h	0000:004Ch	Software	Hard disk drive service
14h	0000:0050h	Software	Serial communications service routines
15h	0000:0054h	Software	System services support routines
16h	0000:0058h	Software	Keyboard support service routines
17h	0000:005Ch	Software	Parallel printer support services
18h	0000:0060h	Software	Load and run ROM BASIC
19h	0000:0064h	Software	DOS loading routine
1Ah	0000:0068h	Software	Real time clock service routines
1Bh	0000:006Ch	Software	CRTL - BREAK service routines
1Ch	0000:0070h	Software	User timer service routine
1Dh	00000074h	Software	Video control parameter table
1Eh	0000:0078h	Software	Floppy disk parameter routine
1Fh	0000:007Ch	Software	Video graphics character routine
20h-3Fh	0000:0080f - 0000:00FCh	SOftware	DOS interrupt points
40h	0000:0100h	Software	Floppy disk revector routine
41h	0000:0104h	Software	hard disk drive C: parameter table
42h	0000:0108h	Software	EGA default video driver
43h	0000:010Ch	Software	Video graphics characters
44h	0000:0110h	Software	Novel Netware API
45h	0000:0114h	Software	Not used
46h	0000:0118h	Software	Hard disk drive D: parameter table
47h	0000:011Ch -	Software	Not used
48h		Software	Not used
49h	0000:0124h	Software	Not used
4Ah	0000:0128h	Software	User alarm
4Bh-63h	0000:012Ch -	Software	Not used
64h		Software	Novel Netware IPX
65h-66h		Software	Not used
67h		Software	EMS support routines
68h-6Fh	0000:01BCh	Software	Not used
70h	0000:01c0h	Hardware	Real time clock
71h	0000:01C4h	Hardware	Redirect interrupt cascade
72h-74h	0000:01C8h - 0000:01D0h	Hardware	Reserved - Do not use
75h	0000:01D4h	Hardware	Math coprocessor exception
76h	0000:01D8h	Hardware	Hard disk support
77h	0000:01DCh	Hardware	Suspend request
78h-79h	0000:01E0h -	Hardware	Not used
7Ah		Software	Novell Netware API
78h-FFh	0000:03FCh	Software	Not used