INT 16 - KEYBOARD - GET 122-KEY SHIFT STATUS (122-key kbd support only)
        AH = 22h
Return: AL = shift flags 1 (see AH=12h)
        AH = shift flags 2 (see AH=12h)
Note:   use AH=09h to determine whether this function is supported
SeeAlso: AH=02h,AH=09h,AH=12h,AH=20h,AH=21h

.