[zykov eddy]

Hello everyone!

I've considered myself to be a DN3D modding archeologist, and most of the time, I could find older maps and TCs and getting them to work, even the ones that weren't available on the internet for many years, or seemed broken/corrupted. But, one TC have bothered me from the very beginning, and it's a Stargate SG-1: In the Hands of a Serpent by David G. Paul, from 1999.

The only version that I could get to work was an older beta that had very few levels and lots of missing graphics. There's a newer version of this TC that seems to have much more content, but I could never get it to work. I can unzip the data file and look through the file names in the GRP, but all files seem to be corrupted. I always assumed that they were broken from the beginning and getting them to work is impossible, but maybe I'm doing something wrong? Maybe they're actually protected in some way, and I could never figure out how to decode them.

If you have any ideas how to decode the files, or have a working version available, please share it here. I would really appreciate it. This TC seems very low quality by 90's Duke 3D modding standards, but it's a part of our history nonetheless, and needs to be preserved. Thank you!

Attached thumbnail(s)

• 

[oasiz]

It looks like that GRP does still contain valid data but perhaps it's headers are busted..
The GRP file kind of relies on the headers to tell you where each file is located, I'll try to see what I can find..

First file is a MAP that I can see from the headers.. last files are audio files and can be heard when imported to i.e. audacity.
I think that some files or data are missing from the middle, which would explain wrong offsets.
Would need some additional analysis.. I tried to fiddle with ImHex to get patterns going on but I still don't know how to exactly do this correctly..
I feel like I'm better off writing a dumper from scratch.

The .com patcher program fiddles with the .exe but it doesn't seem to do anything to magically make the GRP work either (i.e. hardcoded magic offsets).

[MajorTom 2417]

link removed; mod was for Half-Life, but I'll keep looking.

How many files for the mod, if any, exist outside of the apparently busted GRP file?

[zykov eddy]

MajorTom 2417, on 31 August 2025 - 12:28 PM, said:

How many files for the mod, if any, exist outside of the apparently busted GRP file?

I was only able to find three con files, which do work. I tested them with an older version of the TC.

[MajorTom 2417]

I'm consulting with someone else who DL'd the second version and they're telling me there's no GRP file. So either I'm missing something in this discussion or....well, I have no clue. Was the GRP in the data file? And which file was the data file?

So the one I'm talking to says that the second version can be run with vanilla Duke3D 1.3D. Just dump all the files into a directory and go, apparently.

[zykov eddy]

MajorTom 2417, on 31 August 2025 - 01:06 PM, said:

I'm consulting with someone else who DL'd the second version and they're telling me there's no GRP file. So either I'm missing something in this discussion or....well, I have no clue. Was the GRP in the data file? And which file was the data file?

So the one I'm talking to says that the second version can be run with vanilla Duke3D 1.3D. Just dump all the files into a directory and go, apparently.

The latest version of the TC is called Beta 3. There's a sg1tc.dat file in there, that's actually a ZIP file. If you unzip it, you'll get, among other things, a corrupted GRP.

The working version that I was referring to earlier is called Beta 2. That one does not have corrupted files in it.

[MajorTom 2417]

Have you tried running the other stuff in the mod without the GRP you got from the .dat file? Also, are you sure you're using the correct tool to open the .dat file? Just cracking it open with WinZIP may be part of the problem.

[zykov eddy]

MajorTom 2417, on 01 September 2025 - 05:04 AM, said:

Have you tried running the other stuff in the mod without the GRP you got from the .dat file? Also, are you sure you're using the correct tool to open the .dat file? Just cracking it open with WinZIP may be part of the problem.

It could be that opening it like a zip is part of the problem. I tried using WinZip from 2000 and it gave me the same files, corrupted GRP included.
Almost all stuff from the mod is in the GRP. Other than that, there's a map and a couple of con files, all of which are working fine.

[oasiz]

It's a self-extracting zip file, but you can just skip the executable portion itself with most archivers. Just rename it to .exe to get the self-extracting logic.
It expects to be opened under win9x it seems, any 32bit could work I think.

The GRP itself seems to be corrupted but I'm not sure if it's the .zip itself, those tend to have rudimentary CRC checks.
I think the GRP itself is just busted.

The GRP itself is extremely simple in syntax: https://moddingwiki....wiki/GRP_Format
To me it looked like a bunch of the files were intact there (there is no compression in GRP, it's just a linear file kinda like plain tar).
Why kextract and such can operate are due to every file entry just being NAME + SIZE, unlike WAD, there is no "start at this byte".
If even a single byte is missing then it will affect all subsequent files.

As the first files are ABYDOS.MAP and ACTIVATE.WAV, do you have success accessing those even?

[zykov eddy]

oasiz, on 01 September 2025 - 11:09 AM, said:

As the first files are ABYDOS.MAP and ACTIVATE.WAV, do you have success accessing those even?

I can access and even extract themm but they don't work, as the case with the rest of the files.

[MajorTom 2417]

Could the .dat file be a patch file, to update the mod from one version to the next? That might be why the .GRP is screwing up if you're unzipping it

[oasiz]

nah, the .bat just does a bunch of renaming.
the only patch you have is the 12KB whatever .com file that gets renamed and it gets applied against duke3d.exe to generate sg1.exe

I'll have to see if I can manually extract any of the files when I have time

[zykov eddy]

oasiz, on 01 September 2025 - 12:22 PM, said:

I'll have to see if I can manually extract any of the files when I have time

That would be amazing! I wish you luck!