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From: ed@alt.dah.sub.org (Ed Braaten)
Newsgroups: alt.msdos.programmer,comp.os.msdos.programmer,comp.sys.intel
Subject: Re: Object Files Format
Keywords: Object Files, Libraries, MS/DOS
Message-ID: <4013@alt.dah.sub.org>
Date: 24 Nov 90 11:49:45 GMT
References: <3416@litp.ibp.fr>
Organization: Public Access UNIX System for Landkreis/Stadt Dachau, Germany
Lines: 38

card@masi.ibp.fr (Remy CARD) writes:

>	Hi all,
>	I am looking for the MS/DOS object files format (.OBJ files)
>and libraries (.LIB files) format.

OMF 86 files contain a number of records, with each record having 
the following general format:

    ******************************************************
    *  record  *  record   *     record     *  checksum  *
    *   type   *  length   *      data      *            *
    * (1 byte) * (2 bytes) * (variable len) *  (1 byte)  *
    ******************************************************

The Intel specification for 8086 OMF is contained in:

   "8086 Relocatable Object Module Formats"  Order Number 121748-001.

This is the format used by the Intel development tools for the 
8086/88/186/188's.  Microsoft made some minor changes to OMF 86
for debugging support, and for libraries.  There was an excellent
article on OMF 86 and Microsoft's extensions in PC Tech Journal
a number of years ago.  Perhaps someone out there could post the
issue number... 

Years ago, I wrote a utility that "dis-assembled" OMF 86 files.
Unfortunately, I re-wrote it and the "new-and-improved" utility
only dis-assembles OMF386.  If someone is interested in finishing 
the code for OMF 86 files, e-mail me.  Maybe the finished code
would be a candidate for comp.sources.misc...


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        Ed Braaten            |  "... Man looks at the outward appearance, 
Work: ed@imuse.de.intel.com   |  but the Lord looks at the heart."              
Home: ed@alt.dah.sub.org      |                        1 Samuel 16:7b
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