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Six
Registered: Apr 2002
Posts: 289 |
DTL Jetpack BASIC
This was never properly cracked. There's a copy @ http://www.haddewig.de/nogames64/tools.html but it still has dongle protection and won't run. There's a non-protected program on the disk ("ERROR LOCATE"), but the main compiler still needs the dongle to run. There are also no docs.
Why is this one so important to preserve? Because literally LEGIONS of c64 games were written with it.
I had a go at trying to break the protection, and I'm sure I eventually could - but it's a bear.
At the end of each file (and the compiler is compiled with itself, btw) there is a byte sequence. TWO of those bytes indicate whether or not the program is dongle-protected. BUT, fixing a protected DTL-BASIC program is not as simple as changing those bytes. It uses them to calculate a bunch of other values, in multiple places in the runtime library.
The (tape-port) dongle check is also obfuscated, but easy enough to find.
So, this is going to take some serious skill to bust - but once its busted, it opens the door for reversal tools that can be used to resource games like Roadwar 2000.
Any takers? Can I persuade anyone to at least have a look at it? |
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Six
Registered: Apr 2002
Posts: 289 |
TNT, is the decompiler available, or private?
If I had a good description of the file format, I could add it as an output target on my txt2prg tokenizer.
BTW, found the dongle at my warehouse today, but not the docs. The dongle goes in the tape port and has the serial # 355-012-500-201. It'd be interesting to see how specific the dongle is - if any copy of the software will run with any dongle. |
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TNT
Account closed
Registered: Oct 2004
Posts: 189 |
http://sid.fi/~tnt/dtl/
Contains C64 version manual + disks which I believe are my original dumps and their cracked counterparts.
PET manual scans are probably in some directory named "old computer" inside another directory with similar name :) |
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Six
Registered: Apr 2002
Posts: 289 |
Awesome! Thanks for posting this, I'd been looking for it for a while. That decomp of part of Roadwar 2000 gives me enough to work from for figuring out the tokenization.
You mentioned there was a decompiler. Did you write it? |
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TNT
Account closed
Registered: Oct 2004
Posts: 189 |
PET manual added.
Decompiler is for internal use only for a moment. I have fixed a bunch of bugs since July when the above source was generated, but there are still couple of things which need fixing. BASIC extensions and overlays are the latest thing corrected, but there's still work to be done I'm sure. |
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TNT
Account closed
Registered: Oct 2004
Posts: 189 |
Yes, I wrote the decompiler after I did complete disassembly of the runtime library. I get the raw P-code and decompiled basic. Basic code is then fed through another program to do some post-processing like changing "line numbers" to decimal. |
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Moloch
Registered: Jan 2002
Posts: 2924 |
Thanks for posting all of this! Like Six, I've been searching for this manual for a long time. My bad luck, I routinely missed DTL packages on eBay in the last few years. |
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Zer0-X
Account closed
Registered: Aug 2008
Posts: 78 |
I guess no one has a spare dongle to sell?
Could reverse what's it made of, but as it's likely potted in epoxy it would be somewhat "destructive" process. |
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Six
Registered: Apr 2002
Posts: 289 |
I have a dongle. I guess I could sacrifice it for deconstruction if someone was going to document how it worked in such a way that I'd be able to build a new one. |
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TNT
Account closed
Registered: Oct 2004
Posts: 189 |
It would be interesting to see if you get the same key from dongle as I did - 24 02. Just run dongle2.prg with the dongle connected and check the first two hex numbers. My dongle reported 00 after first 16 bits.
I would just use two 74165 chained together for the dongle, Zer0-X wants to know what exactly was used :) |
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Six
Registered: Apr 2002
Posts: 289 |
I should be able to test this this weekend. The printed numbers on all of them are the same, at least. I'm assuming the side that says "DTL BASIC" is up? |
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