Relay-Version: version B 2.10 5/3/83; site utzoo.UUCP
Path: utzoo!linus!security!genrad!decvax!duke!jhb@ecsvax.UUCP
From: jhb@ecsvax.UUCP
Newsgroups: net.micro.apple
Subject: Re: Look Alike Drive Question - (nf)
Message-ID: <1571@ecsvax.UUCP>
Date: Tue, 22-Nov-83 21:41:52 EST
Article-I.D.: ecsvax.1571
Posted: Tue Nov 22 21:41:52 1983
Date-Received: Sat, 26-Nov-83 07:26:12 EST
References: harpo.2073
Lines: 15

If you have a piece of software which will boot on an Apple drive but
not on an Apple look-alike drive, you are unfortunately out of luck.  The
Apple drives are capable of performing various feats which they weren't
designed to do: stepping every quarter track, writing to more than 35 tracks,
and having reproduceable times between tracks.  These features have been
used by many of the copy protection schemes because they are "unreadable"
by standard copy programs.  A protection scheme might include some essential
data in track 36, some data written on track 12.25, and have tracks 15 and
16 synchronized, for example.  Many of the Apple look-alikes aren't
capable of reproducing these tricks: slightly different electronics,
or hardware that was designed slightly differently.  Those drives just
can't run software which uses some of the crazy protection schemes.
-Joe Budge

}i