INT 15 U - newer PS/2; various BIOSes - GET CPU TYPE AND MASK REVISION
AH = C9h
AL = 10h (may be required on some non-PS BIOSes)
Return: AH = 00h
CH = CPU type
03h 80386
04h 80486
CL = mask revision
23h 386SX
Notes:  the BIOS must save DX at startup in order to be able to support this
call; PS/2 Models 56, 57, 90, and 95 are known to support it
the PS/2 BIOS merely reads CMOS locations 190h (type) and 191h (rev)


15C9 - newer PS/2; various BIOSes - GET CPU TYPE AND MASK REVISION