IRQ Assignments

IRQ	Function	Bus Slot Required

IRQ 0	-	System Timer	No (motherboard)

IRQ 1	-	Keyboard	No (motherboard)

IRQ 2(9)	-	Cascade from IRQ 9, Video Card	No (motherboard)

IRQ 3	-	COM2, COM4	Yes (8-bit)

IRQ 4	-	COM1, COM3	Yes (8-bit)

IRQ 5	-	Available (normally LPT2 or Sound Card)	Yes (8-bit)

IRQ 6	-	FD Controller	Yes (8-bit)

IRQ 7	-	LPT1	Yes (8-bit)

IRQ 8	-	Real-time Clock	No (motherboard)

IRQ 9	-	Re-directed to IRQ 2	Yes (8-bit)

IRQ 10	-	Available (normally NICs)	Yes (16-bit)

IRQ 11	-	Available	Yes (16-bit)

IRQ 12	-	PS/2 Bus Mouse	Yes (16-bit)

IRQ 13	-	Math Coprocessor	No (motherboard)

IRQ 14	-	HD Controller	Yes (16-bit)

IRQ 15	-	Available (possibly Secondary HD Controller)	Yes (16-bit)

IRQ Assignments

David D. Scribner

2000-10-22T15:54:00

David Scribner