Deluxe Ski Jump 2 DAT file (or question regarding Turbo Pascal)

Extraction and unpacking of game archives and compression, encryption, obfuscation, decoding of unknown files
mtik333
Posts: 15
Joined: Thu Jul 26, 2018 5:15 am

Deluxe Ski Jump 2 DAT file (or question regarding Turbo Pascal)

Post by mtik333 »

Hello,

There is a very old game written back in (Turbo) Pascal, called Deluxe Ski Jump 2 (see here: http://www.mediamond.fi/dsj2/). Some of data (info about rendering hills, images and maybe sounds) is probably stored in DSJ.DAT file. Sadly, the only software that seems to be able to read it is a obscure one found there:
http://dsjskocznia.piwko.pl/down/edytor.zip

Is there someone here who had chance to write something a little bit complex in (Turbo) Pascal? Although this editor is some kind of UPX-based program, code after trying to disassembly it will be took obviously to the lowest, assembly level. I was wondering if someone had experience with using/preparing some kind of compression or even encryption in this, well, IDE/language? And yes, I know I should Google a little bit before asking here, but I didn't get anything helpful (though maybe studying some Turbo Pascal guides would be the first thing to do), that's why I ask here.

#EDIT: Adding this DAT file.
#EDIT2: So in case anyone is interested in that, it looks like all the data are stored in, I'd say, 'plain' mode. This means that opening this raw file using https://rawpixels.net/ with 324x200 resolution and grayscale will show actual ingame images (4 pixels per row are used for, well, "something").

Also, going towards the end of file the audio data is also stored with no headers (unsigned 8-bit PCM).

This means the pictures can be obviously replaced with ones using the same resolution (the image will be either monochrome or grayscale, I think for some screens color is hardcoded, but hue isn't). Not sure about the audio, it would require investigating from someone who really knows how it could be done back then and how audio is being read from the file and since it was over 20 years ago, it could be some pattern developer invented on his own.

Thanks.
aluigi
Site Admin
Posts: 12984
Joined: Wed Jul 30, 2014 9:32 pm

Re: Deluxe Ski Jump 2 DAT file (or question regarding Turbo Pascal)

Post by aluigi »

If you just need an alternative extractor (that works also for reimporting just in case) you can use this script:
http://aluigi.org/bms/dsj_dat.bms

The extracted files look like raw images indeed, better to ask in the Graphics section if you need help with them.
mtik333
Posts: 15
Joined: Thu Jul 26, 2018 5:15 am

Re: Deluxe Ski Jump 2 DAT file (or question regarding Turbo Pascal)

Post by mtik333 »

aluigi wrote:If you just need an alternative extractor (that works also for reimporting just in case) you can use this script:
http://aluigi.org/bms/dsj_dat.bms

The extracted files look like raw images indeed, better to ask in the Graphics section if you need help with them.


What do you mean by "reimporting"? Do you mean trying to change the content and put it back into game's "DAT" file?

Thanks a lot, maybe I'll try to clean up these 62 files I got from "DAT" file and see what can be done furthermore with it, although the only hope here for such dumbass like me would be to get source code of this game one day.
aluigi
Site Admin
Posts: 12984
Joined: Wed Jul 30, 2014 9:32 pm

Re: Deluxe Ski Jump 2 DAT file (or question regarding Turbo Pascal)

Post by aluigi »

Yeah reimporting is a feature of quickbms activated when you use reimport2.bat.

After you launch reimport2.bat, select the same file and folder you selected during extraction.