Games that were tough to crack...

[modrobert]

Back in the day I had problem cracking Speedball 2 (or if it was Xenon 2, memory fails), but this was more about me being lame than anything else.

I got the original early at an Amiga convention, and for some reason Rob Northen's notes to the developers how to implement the protection was included as a text file on the floppy, it was the only normal Amiga dos file on the disk, game data was track loaded. This helped a little bit, at least some of the advice in the doc how to obfuscate the checks and the general method used.

After a day or two I was down to one remaining Rob Northen check on a scrap output floppy disk used for testing, 4 checks removed, one left right before the game is started, but I gave up after that, it got seriously nested and too complicated for me.

With the tools I have today like Resource and HRTmon (on NMI button), also being more patient and stubborn, it would probably been easier, but back then I had a floppy based system using stock A500 (512kb + 512kb). Excuses...hehe Let's just stick with being too lame.

[lilalurl]

(Most) GCR-related posts moved to a new thread at Toni's request:
http://eab.abime.net/showthread.php?t=94364

I hope I didn't forget any. Since Toni didn't include logs, I had to use my crystal ball to check which one were relevant.

[BarryB]

Originally Posted by lilalurl

(Most) GCR-related posts moved to a new thread at Toni's request:
http://eab.abime.net/showthread.php?t=94364

I hope I didn't forget any. Since Toni didn't include logs, I had to use my crystal ball to check which one were relevant.

Ouch! You bitch

[Juz400]

With software houses like Psygnosis ect creating thier own custom formats to squeeze so much data on the disk would I be right in thinking they would have thier own `in-house` compression/packer utilities and routines?

[jotd]

yes, of course, ex: FUNGUS tools used by Gremlin. ATN/Imploder used by Team 17 (S. Boberg). The list probably goes on. But a lot of software houses used Rob Northen disk & packing routines. Fast, reliable, easy to use.

With compression, the main goal there was to achieve fastest decompression & best packing ratio (compression time wasn't an issue of course). But a custom compressor didn't mean that it's unbreakable. Just let the code uncompress, and patch afterwards. Just a little more tedious because it cannot be unpacked/patched/packed if you don't have the packer part (still in 2018 all unpackers don't have their packer counterparts available for the public, or just in 68000 format, or with a not-so-good packing ratio ex: RNC packing clones)

And in-house compression routine doesn't mean "the best compression routine around". Compression is a science, it's not specific to Amiga like disk format. Sometimes a widespread packer (Powerpacker) is best.

[Juz400]

Yeah, I can imagine the compression time wasnt an issue at all, just leave it all day if need be.
But getting that new release fitted onto a standard floppy!
The sweat while you wait for it to compress!
Will it be small enough?

With say a large 2 disk game
Would just getting it out first on 3 disk release or how long do keep trying until you can fit it on 2 disks but be in 2nd/3rd place?
I know everyone prefer the lower disk count but sometimes not always possible

[jotd]

I say "drop the intro" Some crackers did a very good job shoehorning Zool on 2 $1600 sector disks (standard track) where it came in 2 $1800-sector disks (and the files where fungus packed too).

I guess they unpacked the files, found a much better compressor and replaced the whole loader+compressor stuff. Took ages to load/unpack compared to the original, though.

[modrobert]

For a while there was prestige in releasing cracked "one disk version" of a two disk original game.

[WayneK]

What do you mean "for a while"? Some people (*cough* myself *cough*) have released 1-disk versions semi-recently, and of course there was Wanted Team's excellent 1-disk BC Kid release which was previously thought to be impossible (ARJ to the rescue).

Working 3.5" floppies are more scarce than ever, you would think 1-disk versions would still be things people wanted :P

[Galahad/FLT]

Nitro was a mission to get on one disk

[modrobert]

Originally Posted by WayneK

What do you mean "for a while"?

I meant before it turned into WHDLoad, gotek and preservation dumping.

Originally Posted by WayneK

Some people (*cough* myself *cough*) have released 1-disk versions semi-recently, and of course there was Wanted Team's excellent 1-disk BC Kid release which was previously thought to be impossible (ARJ to the rescue).

EDIT:

I remember long ago, after leeching a "one disk version" of some jet fighter sim from the Alpha Flight /X board in Germany (you know, the one where you were greeted as an incoming flight during landing when logging in), and then uploading it to a Dual Crew Shining /X board in Sweden. The upload disappeared mysteriously after a brief SysOP chat, but I could keep my credz. A few days later there was a one disk DCS version of the same game released. Strange how things work sometimes.

[ross]

Originally Posted by Galahad/FLT

Nitro was a mission to get on one disk

I remember your challenge on this

Sooner or later I will put my hands on it to make it faster on intro loading .

[Hewitson]

Originally Posted by Galahad/FLT

Nitro was a mission to get on one disk

I bet it was. Not even Gaston managed to do it.

[mnemo]

Originally Posted by modrobert

Back in the day I had problem cracking Speedball 2 (or if it was Xenon 2, memory fails), but this was more about me being lame than anything else.

I got the original early at an Amiga convention, and for some reason Rob Northen's notes to the developers how to implement the protection was included as a text file on the floppy, it was the only normal Amiga dos file on the disk, game data was track loaded. This helped a little bit, at least some of the advice in the doc how to obfuscate the checks and the general method used.

Haha, I remember that! The files were still included on the cracked disk 2 of Xenon II. VERY interesting to read. It also had the source files for the RNC unpacker.


MnemoTroN

[sneckburger]

I remember a copy I had of Hook was unplayable probably due to a poor crack. The game would run but things were very glitchy and seemed to get worse the more you played.
My copy of Flashback, parts were translated in French and parts in English for some reason. I eventually acquired an original of that game when I bought my A1200.
Also I remember Jurrasic park wouldn't let you use the level codes on the cracked version. I actually ended up buying the A1200 game just for the 3d levels as it was too much of a challenge on a single set of lives on the copy.

[jarre]

don't know for sure but gateway Y, from golem seems to be a bitch........

found it:

Originally Posted by Galahad/FLT

it is quite an ingeniously setup protection.

So Disk 1 is part interrupt loading format and part standard MFM, with $1900 size tracks.

Disk 2 is entirely interrupt loading format, and that format is like this.

So interrupt disk format is two different sync marks, $4489 and $4522, but the data is structured not as one complete $1900, but as two big "sectors" of $c80 bytes.

So first part of track is $4489 and $c80 worth of data, then the second part of that track is $4522 and also $c80 worth of data.

The problem is that the programmer only loads in $c80 sizes when interrupt loader is running, which means he has set a REALLY small track buffer to decode MFM data, which is neatly positioned inbetween code and onscreen graphics, when wanting to load next half of the track, he just swaps the SYNC and it will load the next part, of course AmigaDOS $4489 style track can not be decoded in such a tiny memory space and there is literally NO room in 512k in which to do it.

The disk format is also quite large, $FA000 per disk, so even if I could find the room, I wouldn't be able to fit all the data on the disks and keep it as two like the original.

Lots of sneaky stuff, like if you try and bypass his interrupt loader entirely, it will miss stuff that is setup in memory for other routines which will crash, lots of self modifying encryption (the weakest part of the protection), checksums (again, strangely weaker than the disk protection), if you try and mess with the interrupt loader, it does stuff like seek to track 83 which is all kinds of fun the first time it happens!!!!!

So now i've had to change the interrupt loader system to a multi loader, I have to preserve chip memory to extra memory so I can load the different parts and then restore that used memory, it was quite the headache to figure out a system that wouldn't fall foul of the programmers stuff trying to trip me up.

Very competent protection, and a few schoolboy errors by me along the way didn't help either!

and also a note from the prgrammer:

"Hi cracker, very good!!! But warning: This could be your last crack signed Hans Tel: Int 43 2633 2100"

[BrooksterMax]

Originally Posted by sneckburger

I remember a copy I had of Hook was unplayable probably due to a poor crack.

Also I remember Jurrasic park wouldn't let you use the level codes on the cracked version. I actually ended up buying the A1200 game just for the 3d levels as it was too much of a challenge on a single set of lives on the copy.

These two I remember quite vividly. Hook, I remember my Mum bought me and was really looking forward to it but even though I had an original copy, it mis-behaved or didn't play right. I can't remember the specific issue but something about a disk was not right. She got a refund, so I never played it until recently under whdload.

Jurassic Park, I had the same issue with the level passwords not working on a copy - again not played it properly until whdload in recent times.

[Pfloyd]

I have only basic cracking skills and did some easy cracks.

I remember digging the game code of "Tower of Babel". It looked like spaghetti code to me - perhaps it used some kind of framework, interpreter etc. And lots of checksums.

[sparhawk]

I wonder if "Little Computer People" from EA was hard to crack on Amiga. I cracked it on C64 and was surprised how easy it was (took me about 20 minutes or so). A friend gave it to me under the condition that I don't pass it on, as only he knows how to copy it because the protection couldn't be bypassed and he was pretty surprised when I called him shortly after he gave it to me and told him that I cracked it.

Never did any cracks on Amiga though, as I never had the need for it.

[jotd]

no , it wasn't hard. Just patch the disk protection code with just:

emu_protect
	move.l	#$1ADB,d0
	rts

(feed the key the game is expecting instead of reading the protected track)