INT 15,80 - Device Open

AH = 80h

BX = device id

CX = process id

on return:

CF = 0 if successful

= 1 if error

AH = 80h for PC & PCjr

= 86h for XT (BIOS after 11/8/82)

- available on the AT, XT 286, PS/2 and XT with BIOS after 11/8/82

- designed for use in simple multitasking