INT 16 - KEYBOARD - GET SHIFT FLAGS
AH = 02h
Return: AL = shift flags
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
SeeAlso: AH=22h,INT 18/AH=02h

See also: 1612

1602 - KEYBOARD - GET SHIFT FLAGS