INT 15,83 - Event Wait

AH = 83h

AL = 0 set interval

= 1 cancel interval (PS/2)

CX,DX = number of microseconds to wait (976 µs resolution)

ES:BX = pointer to memory flag (bit 7 is set

when interval expires)

(granularity is 976 microseconds)

on return:

CF = 1 if function already busy

AH = 80h for PC

= 86h for XT & AT

- available on the AT (BIOS after 1/10/84) and PS/2's except 30

- designed for use in simple multitasking