INT 15,C4 - Programmable Option Select (PS/2)

AH = C4

AL = 0 get Programmable Option Select adapter register address

= 1 enable slot for setup

= 2 adapter enable

on return:

CF = 0 if successful

= 1 if error

AH = when CF set, 80h for PC & PCjr, 86h for XT, AT & 30

BL = slot number (function AL=1)

DL = POS adapter register address (function AL=0)

- allows access to PS/2 Programmable Option Select registers

- available on 80286 and 80386 PS/2's