INT 62 u - FGDRIVER v1.10 - "FG_INTKEY" - GET KEYSTROKE, NO WAIT
        AX = 006Fh
        ES:BX -> variable pointer record (see below)
Return: variables updated
Note:   if the keyboard buffer is empty, both the ASCII and extended keycodes
          are set to 00h
SeeAlso: AX=006Eh,AX=0070h,AX=0079h

Format of variable pointer record:
Offset  Size    Description
 00h    WORD    segment of BYTE buffer for ASCII keycode
 02h    WORD    offset of BYTE buffer for ASCII keycode
 04h    WORD    segment of BYTE buffer for extended keycode
 06h    WORD    offset of BYTE buffer for extended keycode