Int 16 Fn 00  - Keyboard - Get Keystroke                                   [B]

   AH = 00h

Return: AH = BIOS scan code
   AL = ASCII character

Notes: on extended keyboards, this function discards any extended keystrokes,
     returning only when a non-extended keystroke is available
   the BIOS scan code is usually, but not always, the same as the hardware
     scan code processed by INT 09.  It is the same for ASCII keystrokes
     and most unshifted special keys (F-keys, arrow keys, etc.), but
     differs for shifted special keys
   some (older) clone BIOSes do not discard extended keystrokes and manage
     function AH=00h and AH=10h the same
   the K3PLUS v6.00+ INT 16 BIOS replacement doesn't discard extended
     keystrokes (same as with functions 10h and 20h), but will always
     translate prefix E0h to 00h. This allows old programs to use extended
     keystrokes and should not cause compatibility problems

See Also: AH=01h,AH=05h,AH=10h,AH=20h,AX=AF4Dh"K3PLUS",INT 18/AH=00h