Re: How to check which memory locs. are really occupied by BIOS?

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#1407

From: Russ Nelson
Date: Fri, 23 Feb 1990 14:41

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In article <300@ipsi.UUCP> schulz@ipsi.UUCP (Guenther F. Schulz) writes:

   does anybody happen to know a method how to make sure which
   memory areas are really occupied by bios routines (machine
   bios, video bios, div. controller bios...) AFTER BOOTUP?

Checksum the bios roms.  If they checksum correctly, it's a ROM.

They may be at any 2k from c000 (some docs say c800) through e000.
  Byte 0:  55h
  byte 1: 0aah
  byte 2: length in 512-byte blocks
Checksum using addition modulo 100h should be zero.

--
--russ (nelson@clutx [.bitnet | .clarkson.edu])  Russ.Nelson@$315.268.6667
Violence never solves problems, it just changes them into more subtle problems

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Path: arc1-ca.pugleaf.net!utzoo!mnetor!geac!torsqnt!lethe!yunexus!ists!helios.physics.utoronto.ca!jarvis.csri.toronto.edu!cs.utexas.edu!swrinde!zaphod.mps.ohio-state.edu!rpi!image.soe.clarkson.edu!news
From: nelson@sun.soe.clarkson.edu (Russ Nelson)
Newsgroups: comp.sys.ibm.pc.programmer,alt.msdos.programmer
Subject: Re: How to check which memory locs. are really occupied by BIOS?
Message-ID: <NELSON.90Feb23094111@image.clarkson.edu>
Date: 23 Feb 90 14:41:17 GMT
References: <300@ipsi.UUCP>
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Reply-To: nelson@clutx.clarkson.edu
Organization: Clarkson University, Potsdam NY
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In-reply-to: schulz@ipsi.UUCP's message of 22 Feb 90 14:20:09 GMT

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