| Interrupt
| Description
|
| INT 00h
| CPU: Executed after an attempt to divide by zero or when the quotient does not fit in the destination
|
| INT 01h
| CPU: Executed after every instruction while the trace flag is set
|
| INT 02h
| CPU: NMI, used e.g. by POST for memory errors
|
| INT 03h
| CPU: The lowest non-reserved interrupt, it is used exclusively for debugging, and the INT 03 handler is always implemented by a debugging program
|
| INT 04h
| CPU: Numeric Overflow. Usually caused by the INTO instruction when the overflow flag is set.
|
| INT 05h
| Executed when Shift-PrintScreen is pressed, as well as when the BOUND instruction detects a bound failure.
|
| INT 06h
| CPU: Called when the Undefined Opcode (invalid instruction) exception occurs. Usually installed by the operating system.
|
| INT 07h
| CPU: Called when an attempt was made to execute a floating-point instruction and no numeric coprocessor was available.
|
| INT 08h
| IRQ0: Implemented by the system timing component; called 18.2 times per second (once every 55 ms) by the PIC
|
| INT 09h
| IRQ1: Called after every key press and release (as well as during the time when a key is being held)
|
| INT 0Bh
| IRQ3: Called by serial ports 2 and 4 (COM2/4) when in need of attention
|
| INT 0Ch
| IRQ4: Called by serial ports 1 and 3 (COM1/3) when in need of attention
|
| INT 0Dh
| IRQ5: Called by hard disk controller (PC/XT) or 2nd parallel port LPT2 (AT) when in need of attention
|
| INT 0Eh
| IRQ6: Called by floppy disk controller when in need of attention
|
| INT 0Fh
| IRQ7: Called by 1st parallel port LPT1 (printer) when in need of attention
|
| INT 10h
| Video Services - installed by the BIOS or operating system; called by software programs
| AH=00h
| Set Video Mode
|
| AH=01h
| Set Cursor Shape
|
| AH=02h
| Set Cursor Position
|
| AH=03h
| Get Cursor Position And Shape
|
| AH=04h
| Get Light Pen Position
|
| AH=05h
| Set Display Page
|
| AH=06h
| Clear/Scroll Screen Up
|
| AH=07h
| Clear/Scroll Screen Down
|
| AH=08h
| Read Character and Attribute at Cursor
|
| AH=09h
| Write Character and Attribute at Cursor
|
| AH=0Ah
| Write Character at Cursor
|
| AH=0Bh
| Set Border Color
|
| AH=0Eh
| Write Character in TTY Mode
|
| AH=0Fh
| Get Video Mode
|
| AH=13h
| Write String
|
|
| INT 11h
| Installed by the BIOS; returns equipment list
|
| INT 12h
| Installed by the BIOS or operating system; returns Conventional Memory Size
|
| INT 13h
| Low Level Disk Services; installed by the BIOS or operating system; called by software programs
| AH=00h
| Reset Disk Drives
|
| AH=01h
| Check Drive Status
|
| AH=02h
| Read Sectors From Drive
|
| AH=03h
| Write Sectors To Drive
|
| AH=04h
| Verifies Sectors On Drive
|
| AH=05h
| Format Track On Drive
|
| AH=08h
| Get Drive Parameters
|
| AH=09h
| Init Fixed Drive Parameters
|
| AH=0Ch
| Seek To Specified Track
|
| AH=0Dh
| Reset Fixed Disk Controller
|
| AH=15h
| Get Drive Type
|
| AH=16h
| Get Floppy Drive Media Change Status
|
|
| INT 14h
| Routines for communicating via the serial port. Used by software programs.
| AH=00h
| Serial Port Initialization
|
| AH=01h
| Transmit Character
|
| AH=02h
| Receive Character
|
| AH=03h
| Status
|
|
| INT 15h
| Miscellaneous (System services support routines)
| AH=4FH
| Keyboard Intercept
|
| AH=83H
| Event Wait
|
| AH=84H
| Read Joystick
|
| AH=85H
| Sysreq Key Callout
|
| AH=86H
| Wait
|
| AH=87H
| Move Block
|
| AH=88H
| Get Extended Memory Size
|
| AH=C0H
| Get System Parameters
|
| AH=C1H
| Get Extended BIOS Data Area Segment
|
| AH=C2H
| Pointing Device Functions
|
| AH=0E8h, AL=01h (AX = 0E801h)
| Get Extended Memory Size(Newer function, since 1994). Gives results for memory size above 64 Mb.
|
|
| INT 16h
| Implemented by the BIOS or operating system. Provides routines to be called by software programs which communicate with the keyboard.
| AH=00h
| Read Character
|
| AH=01h
| Read Input Status
|
| AH=02h
| Read Keyboard Shift Status
|
| AH=10h
| Read Character Extended
|
| AH=11h
| Read Input Status Extended
|
| AH=12h
| Read Keyboard Shift Status Extended
|
|
| INT 17h
| Print Services - used by software programs to communicate with the printer
| AH=00h
| Print Character to Printer
|
| AH=01h
| Initialize Printer
|
| AH=02h
| Check Printer Status
|
|
| INT 18h
| Execute Cassette BASIC: True IBM computers contain BASIC in the ROM to be interpreted and executed by this routine in the event of a boot failure (called by the BIOS)
|
| INT 19h
| After POST this interrupt is used by BIOS to load the operating system.
|
| INT 1Ah
| Real Time Clock Services - called by software programs to communicate with the RTC
| AH=00h
| Read RTC
|
| AH=01h
| Set RTC
|
| AH=02h
| Read RTC Time
|
| AH=03h
| Set RTC Time
|
| AH=04h
| Read RTC Date
|
| AH=05h
| Set RTC Date
|
| AH=06h
| Set RTC Alarm
|
| AH=07h
| Reset RTC Alarm
|
|
| INT 1Bh
| Installed by the operating system; automatically called by INT 9 when Ctrl-Break has been pressed
|
| INT 1Ch
| Called automatically by INT 08; available for use by software programs when a routine needs to be executed regularly
|
| INT 1Dh
| Not to be called; simply a pointer to the VPT (Video Parameter Table), which contains data on video modes
|
| INT 1Eh
| Not to be called; simply a pointer to the DPT (Diskette Parameter Table), containing a variety of information concerning the diskette drives
|
| INT 1Fh
| Not to be called; simply a pointer to the VGCT (Video Graphics Character Table), which contains the data for ASCII characters 80h to FFh
|
| INT 41h
| Address pointer: FDPT = Fixed Disk Parameter Table (1st hard drive)
|
| INT 46h
| Address pointer: FDPT = Fixed Disk Parameter Table (2nd hard drive)
|
| INT 4Ah
| Called by RTC for alarm
|
| INT 70h
| IRQ8: Called by RTC
|
| INT 74h
| IRQ12: Called by mouse
|
| INT 75h
| IRQ13: Called by math coprocessor
|
| INT 76h
| IRQ14: Called by primary IDE controller
|
| INT 77h
| IRQ15: Called by secondary IDE controller
|
