Path: utzoo!utgpu!jarvis.csri.toronto.edu!mailrus!iuvax!rutgers!cmcl2!ccnysci!alexis
From: alexis@ccnysci.UUCP (Alexis Rosen)
Newsgroups: comp.sys.mac
Subject: Re: Breaking Mediagenics' copy protection
Keywords: copy protection, mediagenics, copy II mac
Message-ID: <1215@ccnysci.UUCP>
Date: 2 Feb 89 07:38:58 GMT
References: <1226@xn.LL.MIT.EDU> <81044@felix.UUCP>
Reply-To: alexis@ccnysci.UUCP (Alexis Rosen)
Organization: City College of New York
Lines: 20


I can't tell you how to defeat the copy protection on Shanghai (I'm sure
it's not too difficult, though, I've seen deprotected versions). I can
tell you how to defeat that horribly annoying shutdown at the end.

Look in all of the CODE resources for a sequence of bytes like this:
3F3C 000x A895
where the x is either 1 or 2. This pushes a word onto the stack and
calls the Shutdown trap. Replace this with:
A9F4 4E71 4E71
which is an ExitToShell and two No-ops.

Note: I have not tried this (I don't have shanghai). Since you need to do
this on an original, make DAMN SURE you know what you're doing and can
reverse the change if I've screwed up somewhere.

Caveat Emptor.

Alexis Rosen
alexis@ccnysci.uucp