Int 16 Fn 51  - Keyboard - Ax Pc - Read Shift Key Status                   [J]

   AH = 51h

Return: AL = standard shift key states (see #0506,#0511)
   AH = Kana lock (00h off, 01h on)

Note:  also supported by K3PLUS v6.00+, but K3PLUS always returns AH=00h

See Also: AH=02h,AH=12h,AH=22h