Newsgroups: comp.os.msdos.programmer
Path: utzoo!utgpu!watserv1!broehl
From: broehl@watserv1.waterloo.edu (Bernie Roehl)
Subject: Re: Reading antiquated disk formats
Message-ID: <1990Oct3.204412.760@watserv1.waterloo.edu>
Organization: University of Waterloo
References: <85968@aerospace.AERO.ORG>
Date: Wed, 3 Oct 90 20:44:12 GMT
Lines: 29

In article <85968@aerospace.AERO.ORG> goldstein@arecibo.aero.org (Fogbound Child) writes:
>The formats and machines are as follows:
>
>FORMAT			OPERATING SYSTEM		MACHINE
>---------------------------------------------------------------
>[...]
>40 track, SS, DD        Newdos 80 v2                    TRS-80 Mod I
>40 track, DS, DD        Newdos 80 v2                    TRS-80 Mod I

The problem is that the Mod I, like other machines of its generation, wrote
track 0 in single-density mode.  You have to get down and dirty and reprogram
your disk controller chip to handle the FM vs MFM format.

The sector number is a minor issue, as I recall...

You should pick up a copy of "TRS-80 Disk and Other Mysteries", in which
the TRSDOS/NEWDOS/LDOS disk formats are described in complete detail.

It's rather bizarre, really... you read your boot block to find out what
track the directory is stored on, then go through the directory entries
and their "extents", then do something involving a dead goat under a full
moon... you get the idea.


-- 
	Bernie Roehl, University of Waterloo Electrical Engineering Dept
	Mail: broehl@watserv1.waterloo.edu OR broehl@watserv1.UWaterloo.ca
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