[comp.sys.mac.programmer] Subverting copy-protection schemes

jnh@ecemwl.ncsu.edu (Joseph N. Hall) (07/26/89)

I'm trying to get some games installed in a partition on my hard disk
and I've been de-protecting as many of them as possible, given my relatively
limited experience in this area.  I'm stuck, though, on Patton vs. Rommel.

I figure that if I could only get PVR loaded and running in memory with
TMON, I could pretty easily modify the appropriate code resources.  TMON,
though, doesn't coexist with PVR, apparently, whether loaded into the
system heap or high memory.  (PVR comes on a 400k disk, so it's kind of
a tight fit ... I had to de-protect and temporarily remove many of the
endgame screens just so that I could get TMON running.)  Anyway, the
system reboots shortly after I click on PVR with TMON installed.
Very frustrating.

The copy-protect system uses a specially-written sector on the floppy
(in this case, sector 20H).  I have no idea yet whether an executable
portion of the game is stored there.  If not, I suppose I could load,
examine, and perhaps step through the game's code resources with TMON ...

I dunno.   I'm sure there's a trick to this that I'm missing ... any
suggestions?

	-joseph hall
	-jnh@ecemwl.ncsu.edu
	-joseph@ece007.ncsu.edu