Xref: utzoo comp.sys.ibm.pc.programmer:98 alt.msdos.programmer:1298 Path: 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: Date: 23 Feb 90 14:41:17 GMT References: <300@ipsi.UUCP> Sender: news@sun.soe.clarkson.edu Reply-To: nelson@clutx.clarkson.edu Organization: Clarkson University, Potsdam NY Lines: 18 In-reply-to: schulz@ipsi.UUCP's message of 22 Feb 90 14:20:09 GMT 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