Int 16h, 11h            Extended Keyboard Status                         many

    Checks to see if a character is available in the buffer. This
    service is provided to support the extended keyboard (101/102-key
    keyboard).

        Entry   AH = 11h

        Return  ZF = 0, if character is available
                     1, if character is not available
                AX = If character is available, then set to
                     character as in Service 10h

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    This service is supported only on the AT dated 11/15/85 and after,
    the XT dated 1/10/86 and after, and the XT-286.

    If a character is available, the Zero Flag is cleared and AX
    contains the ASCII value in AL and the scan code in AH. The
    character is not removed from the buffer. Use Service 10h to
    remove the character from the buffer. See Service 10h for a
    complete description of the meaning of AX if a character is
    available.

    This service is excellent for clearing the keyboard or allowing a
    program to be interruptable by a specific key sequence.

    See Service 01h for an equivalent service that works with all
    keyboards, not supporting the new keys on the enhanced
    (101/102-key) keyboard.