INT 16 - Compaq 386 - SET CPU SPEED
        AH = F0h
        AL = speed
            00h equivalent to 6 MHz 80286 (COMMON)
            01h equivalent to 8 MHz 80286 (FAST)
            02h full 16 MHz (HIGH)
            03h toggles between 8 MHz-equivalent and speed set by system board
                switch (AUTO or HIGH)
            08h full 16 MHz except 8 MHz-equivalent during floppy disk access
            09h specify speed directly
                CX = speed value, 1 (slowest) to 50 (full), 3 ~= 8088
SeeAlso: AH=F3h