Re: WANTED: Information on Apple II copy protection

[mkelsey@spam.eecs.wsu.edu]

In article <350F830D.B36A2C41@swbell.net>,
	Rubywand <rubywand@swbell.net> writes:
> Michael Kelsey - Systems Staff writes ..
>> 

>      Shamus, Frogger, and Frogger II have all been cracked. There is no
> information about Shamus's original protection. My version is a copy-- a
> file included with a couple other games on a diskette side.

Right.  Before Asimov was up and running I didn't even know that anybody
else in the world even had Shamus.  Well, hmmm..I would still like to 
know what protection it uses.  It appears to be VERY sensative to disk
speed.  I felt like I was cheating by capturing it in memory; other than
the fact that I was able to finish playing out the game; it didn't have
any type of save feature :P 

One of two reasons why disk speed might be an issue:  synchronized
tracks OR it relies on accurate disk speed to "place" it at the next
correct sector.  Like I stated before, it uses huge gaps of invalid
bytes and "bing!" suddenly valid data follows.  What other programs
did Synapse make around 1983?  Maybe this can shed some light.

By listening to the drive it appears to be using whole tracks, or maybe
even 1.5 tracks, I can't tell.  I never owned Flight Simulator I, which
happened to be the only program that I knew used half tracks.

F-15 Strike Eagle used 1/3 tracks and sounds VERY different from programs 
like AirHeart, Dazzle Draw and Where in the World is Carmen Sandiego,
which all use 1/4 tracks.  Likewise, Shamus doesn't sound like any of these,
nor does it sound like it's performing synchronized tracks, e.g. Wizardry.

Usually you can tell what scheme is used, just by listening, but Shamus
uses a lop-sided disk increment.  Sounds very much like:

tka-tka tka-tka tka-tka tka-tka tka-tka tka-tka (so forth)

Most fast DOS copiers (Jet Copy or Locksmith 5.0 Fast Backup) give:

tut tut tut tut tut tut tut tut tut tut tut tut (a tut for each track)

Quarter tracks sound like a purring cat when accessed sequentially.

>      Sega appears to have used spiral "arc tracking" to protect its
> Frogger diskettes. It was recognized as a very tough protection to
> defeat. One Computist contributor outlined patches which lead to a copy
> with slightly glitchy performance. The original (and best) crack seems

Do you know where I might begin looking for this outlined patch?  I never
subscribed to Computist and learned everything by experimenting with 
(many many) bit copiers.  I wouldn't even know what time frame to begin
looking!

> to be the one you used-- i.e. capturing the program in RAM.

With the exception that Frogger "parked" it's hires font at $0300 or $0400;
I don't remember which, but I know it was impossible (for me) to obtain.
The Control-ClosedApple-Reset technique would cost you everything from
$0000-$0802.  I had to rip off the font from the only other program
I had from that era - CannonBall Blitz.  Other than that, it was
the only way I could make an efficient operable copy of Shamus, Frogger
and Where in the World is Carmen Sandiego.

>      There is no mention of Hubbard Star Gazer in Computist's "SoftKeys"
> index and it does not appear in my collection or in any of my 5.25" Copy
> II+ lists. Given the title, this could mean that it is educational
> software that no one was much interested in copying. One possible
> shortcut for copying such wares is to look for wares from the same
> vendor for which there are cracks. A vendor will often employ the same
> or a very similar protection for several products.

Or a company has a copier for it, e.g. Print Shop and Dazzle Draw, or
MECC's licensed copier (which by the way wouldn't copy itself, by
default ;)

Hubbard Star Gazer would be considered an educational title.  Are there
any other titles even listed by Hubbard during the 1980's?  I don't have
the original in my possession any more (I could probably get it though) 
but I have retained a possible "corrupt" backup.  I am led to believe
that each track may have had timing bits (E7 FC EE type) on each track
that would be included in the 6&2 decoding.  It's just a guess, though.

Thanks for all of your advice!

-- 
	-/\/\ichael-

replyto: mkelsey at eecs.wsu.edu