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Path: utzoo!utcs!lsuc!pesnta!hplabs!nsc!voder!gino
From: gino@voder.UUCP (Gino Bloch)
Newsgroups: net.micro.pc
Subject: Re: Dos Startup modification
Message-ID: <672@voder.UUCP>
Date: Tue, 12-Feb-85 13:49:25 EST
Article-I.D.: voder.672
Posted: Tue Feb 12 13:49:25 1985
Date-Received: Thu, 14-Feb-85 18:55:27 EST
References: <307@psivax.UUCP> <431@ahuta.UUCP> <319@psivax.UUCP>
Organization: National Semiconductor, Santa Clara
Lines: 17

[munch]

> I have heard that the BIOS ROM determines that the machine has been powered-
> up once already by examining two memory locations and checking them against
> the pattern 0x12 , 0x34.  I forgot which locations have this (see the BIOS
> listing in the Tech. Ref. Manual for more details). If these locations contain
> the pattern then the BIOS skips the memory test.  One could construct a 
> circuit that decodes those memory locations to "fool" the BIOS into thinking
> that it tested the memory already.
There is a company (I forget their name - my memory wasn't tested when I booted
up this morning) that makes such a device.  Jerry Pournelle mentioned it in
Byte, both June & July 1984.  The price is $70 - seems high to me.  I have
guessed that they use the scheme you mention, but I don't know.  I also don't
know if it works on my clone (Compaq).
-- 
Gene E. Bloch (...!nsc!voder!gino)
The opinions expressed above are accidents.