INT 16 - KEYBOARD - GET EXTENDED SHIFT STATES (enh kbd support only)
AH = 12h
Return: AL = shift flags 1 (same as returned by AH=02h)
bit 7: Insert active
6: CapsLock active
5: NumLock active
4: ScrollLock active
3: Alt key pressed (either Alt on 101/102-key keyboards)
2: Ctrl key pressed (either Ctrl on 101/102-key keyboards)
1: left shift key pressed
0: right shift key pressed
AH = shift flags 2
bit 7: SysRq key pressed
6: CapsLock pressed
5: NumLock pressed
4: ScrollLock pressed
3: right Alt key pressed
2: right Ctrl key pressed
1: left Alt key pressed
0: left Ctrl key pressed
Notes:  AL bit 3 set only for left Alt key on many machines
AH bits 7 through 4 always clear on a Compaq SLT/286
SeeAlso: AH=22h,AH=51h

See also: 1602

1612 - KEYBOARD - GET EXTENDED SHIFT STATES (enh kbd support only)