INT 16 - KEYBOARD - AX PC - READ SHIFT KEY STATUS
AH = 51h
Return: AL = standard shift key states (see AH=12h)
AH = Kana lock (00h off, 01h on)
SeeAlso: AH=12h,AH=22h

See also: 1602

1651 - KEYBOARD - AX PC - READ SHIFT KEY STATUS