Re: Genesis deprotection

[Hot Rod <hotrod.apple2@gmail.com>]

On Saturday, July 21, 2012 11:18:36 AM UTC-5, bloomer_au wrote:
> As I've spent more time on comp.sys and become more archive minded, I've started to appreciate the value of obtaining clean copies of games for posterity, free of crack screens or impossible high score lists. Or that just plain work (For instance, I don't think Adventure Construction Set from asimov actually works.) So I thought it's time I start trying to get some of these clean copies from my own collection of purchased games.
> 
> I thought I'd start with Genesis, a spider vs scorpions shoot em up I have. The only copy I've found on asimov is a file-based crack with an edited title screen, as per these lines from the index:
> 
> ./images/games/file_based/axisassassin_genesis_tubewayii.dsk.gz
> ./images/games/file_based/axisassassin_genesis_tubeway][.dsk.gz
> 
> There's an article on deprotecting it in Computist issue 53, and it looked like a relatively easy one to deprotect. I've never deprotected anything before.
> 
> http://archive.org/details/computist-scan-53 (pages 15-16 of the pdf)
> 
> Well, I had a great time doing this. I started by cleaning the disk. Then I had to use the the 'RAMcard trick', which I learned about from Computist #16:
> 
> http://archive.org/details/computist-scan-16 (pages 11-13 of pdf)
> 
> So I booted the game into aux memory with the utility program I had typed in from the magazine, hit reset, copied it back into main memory, tweaked it as per instructions and BSAVED the result. Then I verified that this file ran fine on my IIGS.
> 
> Next, I copied it over to my Mac with ADTPro, but there I found it doesn't run on any of my emulators. After BRUNning, it crashes to the monitor, though the crash screen is different depending on whether it's a virtual IIGS or IIE:
> 
> IIE says:
> 80C3-    A=09 X=8D Y=80 P=B1 S=EE
> *
> 
> IIGS says:
> 00/80C1: 00 00        BRK 00            
>  A=0409 X=008D Y=0080 S=01F2 D=0000 P=B1
>  B=00 K=00 M=0C Q=00 L=1 -=1 8=1 %=1    
> *
> 
> The deprotection instructions mentioned that the crack actually made the game more compatible across Apple II models, saying that it deactivated a bunch of opcodes that prohibited it running on the IIC in the process, for instance. So my guess is - the game is more finicky than the cracker realised in some way (though why would it run only on a real IIGS?), or... well, I dunno. Tomorrow I will copy the file over ADTPro again, just to make sure it wasn't a bad transfer.
> 
> Do any of you real crackers have any ideas?
> 
> - Wade

Kinda hard to say without looking at what it's doing.  I can peek at it if you can send what you currently have.  There's nothing in the Comptist article that would suggest a specific issue.

Are you able to send stuff via ADTPro that is able to then work in an emulator?  Maybe that's a place to start (to confirm there's no issue with that chain).

I have a working copy of Adventure Const Set (cracked though, from way back). It does take a while to boot in AppleWin - there is a delay as the EA boot works its way through.  Pretty sure there's an article in Computist about it too...  :)

]HR