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From: spolsky-joel@cs.yale.edu (Joel Spolsky)
Newsgroups: comp.os.msdos.programmer
Subject: Re: Testing for ALT keypress
Message-ID: <26242@cs.yale.edu>
Date: 19 Sep 90 03:57:30 GMT
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In article <Fdatuc52@cs.psu.edu> melling@cs.psu.edu (Michael D Mellinger) writes:
>I am trying to test when a user presses ALT-h, but am not having much
>luck.  I found these two library routines in the Microsoft C 6.0
>library reference manual, but they don't seem to do the trick for ALT
>key sequences(They work fine for Cntrl and Shift keys, however).  I
>was masking ch with 0xff to get the proper ascii character and testing
>bit 3 in altpress.  Is there something else that I have to do?

You're doing it wrong; bioskey returns scancodes for the ALT keys,
not ASCII values. It sets the low byte of the result to 0.
Look at the *high* byte of the result, that reflects the keyboard
scancode of the ALT-key combination pressed.

Joel Spolsky
spolsky@cs.yale.edu                                     Silence = Death