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Path: utzoo!watmath!clyde!bonnie!akgua!mcnc!duke!amb
From: amb@duke.UUCP (A. Michael Berman)
Newsgroups: net.micro.pc
Subject: Re: Help needed on Shift, control keys
Message-ID: <6594@duke.UUCP>
Date: Tue, 19-Nov-85 08:58:14 EST
Article-I.D.: duke.6594
Posted: Tue Nov 19 08:58:14 1985
Date-Received: Thu, 21-Nov-85 07:09:40 EST
References: <395@ihdev.UUCP> <1872@watdcsu.UUCP>
Reply-To: amb@duke.UUCP (A. Michael Berman)
Organization: Duke University
Lines: 16
Summary: 

In article <1872@watdcsu.UUCP> broehl@watdcsu.UUCP (Bernie Roehl) writes:
>In article <395@ihdev.UUCP> pdg@ihdev.UUCP (P. D. Guthrie) writes:
>>
>>     Somewhere in the address-space of the IBM pc is a byte that indicates
>>     the current status of all the shift keys on the keyboard, including
>>     the normal-shifts, ctrl-key, scroll-lock, and num-lock keys.
>
...
>                               In the original PC, this bye was stored at
>offset 17H in the ROM BIOS data segment (segaddr 40H).  This may be different
>in different releases of the PC rom, it may be different in the XT, the AT
>and the JR, and will almost certainly be different in clones.  
In at least one clone (Heath/Zenith 150pc family) it is done in exactly the
same way.  In fact, virtually all the important bios memory locations are (and
must) be the same.  This is one distinction between a "true" or "near-clone"
and a generic MS-DOS machine.