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From: lenoil@mit-eddie.UUCP (Robert Scott Lenoil)
Newsgroups: net.micro.cbm
Subject: Re: Copy protected disks
Message-ID: <3651@mit-eddie.UUCP>
Date: Mon, 18-Feb-85 17:23:29 EST
Article-I.D.: mit-eddi.3651
Posted: Mon Feb 18 17:23:29 1985
Date-Received: Wed, 20-Feb-85 20:17:20 EST
References: <414@bonnie.UUCP>
Reply-To: lenoil@mit-eddie.UUCP (Robert Scott Lenoil)
Organization: MIT, Cambridge, MA
Lines: 13

This month's COMPUTE! (or was it COMPUTE GAZETTE?) had a neat article on
write protecting disks.  It involved changing the flag byte on track 18,
sector 0 of the disk that flags the DOS version.  Changing that value
allowed the 1541 to read the disk, but refuse to write to it on the
grounds that it was a different DOS type.  To unprotect the disk, you
issue a memory write command to the 1541, to trick it into thinking that
its DOS version corresponds to the one on the disk.  Unfortunately, I
only had a peek at this article.  Could someone with access to it please
post the specifics?

Robert Lenoil
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