From:	"Mr A Appleyard" <MCLSSAA2 AT fs2 DOT mt DOT umist DOT ac DOT uk>
Organization:	Materials Science Centre
To:	DJGPP AT delorie DOT com
Date:	Tue, 12 May 1998 15:36:01 GMT
Subject:	I wrote a TSR to read the raw keyboard events in DOS mode
Message-ID:	<7F92846091@fs2.mt.umist.ac.uk>

  If anyone wants it, I wrote a program AAKEYS.COM which drops a TSR which
hooks interrupt 9 and adds more options to interrupt 0x16, so DOS programs can
read the raw keyboard events:-
    AX = 0x0600 : read from the key-event buffer one keyboard event and return
it in AL. Carry is clear. Prefix-code combinations are sent on as two events
as they are and are not decoded. Note two special return codes:-
      AL==0xff :  Here the key-event buffer got full. Note that the sequence
                  `prefix, 0xff' may occur.
      AL==0x00 and carry set : The key-event buffer was empty.
    AX = 0x0601 : Empty the key-event buffer.
    AX = 0x0602 : Try to remove this TSR.
    AX = 0x0603 : On return ES:BX points to AAKEYS's 256-byte circular buffer,
                  ES:AX points to that buffer's read & write pointers.
    AX = 0x0604 : Empty the ordinary keyboard buffer by resetting its pointers
    AX = 0x0605 : Stop sending the keyboard events on for usual processing.
    AX = 0x0606 : Resume sending the keyboard events on for usual processing.
    AX = any other 0x06** value: set AX to 0xBEEF (installation check).
    AX = any other value: what it did before.

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