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From: slsw2@cc.usu.edu
Newsgroups: comp.os.misc
Subject: Re: Fooling IBM PC disk device
Message-ID: <1990Oct27.133944.41293@cc.usu.edu>
Date: 27 Oct 90 19:39:44 GMT
References: <858@ucthpx.UUCP>
Followup-To: comp.os.misc
Lines: 26

In article <858@ucthpx.UUCP>, gram@uctcs.uucp (Graham Wheeler) writes:
> A friend of mine has written a computer game, and he would like to try
> to sell it. He wants some form of simple copy protection (just to prevent
> the basic DOS commands from copying the disk). I said I would try to do
> this for him.
> 
> My approach has been to try to either:
> 
> i) Format a 41st track on a 40 track diskette
> ii) Format one track with 4 1024-byte sectors

Much as I hate to be giving advice on implementing copy protection, there's
a simpler way that doesn't require mucking about with the driver parameter
tables or assuming that every drive out there can access a 41st track.

You give the BIOS a list of Cylinder, Head, Sector, and Size bytes when you
format a track. Simply set one of the Sector numbers to 255 on an otherwise
normal track.
-- 
===============================================================================
Roger Ivie

35 S 300 W
Logan, Ut.  84321
(801) 752-8633
===============================================================================