DOS interrupts vs int86() invoked interrupts

[JKaur]

hello frnds,

please tell me the difference between DOS interrupts and interrupts invoked using int86() function in C (are those 8086 intrupts?). In some text i have read these are different, but how??

Do IRQs overlap between two types of interrupts or not?

[jwwicks]

There's no difference that I've ever heard of. int86 can invoke all DOS interrupts, infact that's what it's designed for. There are BIOS supported interrupts 0-15 with 2 and 9 being exclusive so effectively only 15 IRQ's available. DOS interrupts are generally associated with int21 calls.

Not sure what you mean by overlap in IRQ's/Interrupts??

IRQ's can be shared if the OS/BIOS supports the practice. IRQ 2 and 9 "overlap" in that you can use one or the other.

The definitive guide is of course Ralph Brown's list.

JW