From: muehlenf AT sbox DOT tu-graz DOT ac DOT at (Arndt Muehlenfeld)
Newsgroups: comp.os.msdos.djgpp
Subject: Re: Keyboard
Date: Fri, 21 Aug 1998 11:39:30 GMT
Organization: Graz University of Technology, Austria
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On Thu, 20 Aug 1998 15:09:19 -0400, "Sean Middleditch"
<aweplay AT hotmail DOT com> wrote:

>I have found that 0 is returned before extended keys, or at least the F
>keys; arrow keys; and Home, Delete, etc. keys.  As for the left-alt vs.
>right-alt, I may be completely incorrect.
This is correct if you call Int 16h to get keyboard input.
The keyboard handler for Int 9h uses key scan codes which allow to
determine every key combination pressed by the user.
The extended function byte in scan codes is E0h which is in fact 224.
Make codes (key down) are distinguished from release codes (key up) by
a F0h byte. For example, when Escape is pressed, the make code is 01h.
Upon release the scan code bytes are F0h,01h.
Extended functions:
Right-Ctrl down:	E0h,14h
Right-Ctrl up:	E0h,F0h,14h

Arndt