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Re: Torpedo Fire by SSI
heuser.marcus@freenet.de wrote:
On Aug 4, 3:41 am, "Michael J. Mahon" <mjma...@aol.com> wrote:
I was hoping that others might be inspired to play, too. ;-)
Getting past copy protection schemes is not so much black art as
just thinking differently about how to get things done...
I have no experience in cracking software as I never had to
crack my own programs so your descriptions came quite handy! ;-)
I'm glad!
If one tries to load a scenario and confirm by pressing ENTER
the program lists all files on that disk. The game disk itself
contains 10 Applesoft programs on 325 sectors, 70 sectors in
what I think binary files for machine language subroutines for
graphics & ampersand extensions and finally several sectors
in data files.
That doesn't surprise me.
So the P2 program is only a fraction of the whole affair
and not all Applesoft programs can be saved that easily as
they have the normal (?) starting addresses ($0801) when no
graphics mode is utilized (the Shipyard program P1A for example)
or they can't be broken into that easily.
It looks like creating an untrapped error works for P2, so
maybe it will work for others...
And a program starting at $801 is not a problem if a disk
is booted without a HELLO program...
Of course, the direct approach is to look up info on SSI
DOS and go for direct transfers of the programs. Then there's
the issue of reverse-engineering the M/L programs to find out
how to make them work in a normal DOS or ProDOS environment.
(This may be tricky, since one motivation for SSI DOS may be
to free up additional memory for the game.)
Additionally the machine language extensions are nothing to
sneeze at - definitely more than a fun afternoon but if somebody
wants to enhance the program it could be a good start.
Good point. But most of it is likely independent of peculiarities
of SSI DOS and any copy protection mechanisms. Though there are
certainly exceptions, the majority of copy protection schemes have
just a few levels to unravel.
-michael
AppleCrate: An Apple II "blade server"!
Home page: http://members.aol.com/MJMahon/
"The wastebasket is our most important design
tool--and it's seriously underused."