Date   : Thu, 14 Oct 1999 09:29:46 +0100 (GMT)
From   : Peter Hatton <bramley@...>
Subject: Re: Protection schemes

On Wed, 13 Oct 1999, Rick Galbraith wrote:

> Sometimes people come across copy protection, and I wanted to share a simple
> method of keeping the disk catalogue non-viewable on dfs disks. It involved
using in
> the title block of the catalogue sectors characters which were out of the
viewable 
> range, specifically ASCII zero. I once copied the catalog block to another
location,
> re-wrote the block, and put it back.  Then the catalog was visible.
> 
> What other protection schemes were in use?

Another scheme involved setting the 8th bit of the filename in the
catalog, which prevents the filename from being displayed when the
user does a *CAT.  But I think if you did a *INFO *.* it would show up. 
The first time I saw it used was on the game Exile.

Peter Hatton
E-mail:  bramley@...
Webpage: http://www.termisoc.org/~bramley
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