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Compressed DAT files on many Saturn Games

UltraDev - Aug 7, 2001

		UltraDev		Aug 7, 2001
			I have ran into archive files, that contain many other files. How would I go about opening them. I have tried Winrar and Winace I haven't bothered with WinZip b/c it's so lame.

		IceDigger		Aug 7, 2001
			they tend to be compressed in a developer- or gamespecific format.. none of the common stuff.

		UltraDev		Aug 7, 2001
			Well, do you know what I can do about it?

		IceDigger		Aug 9, 2001
			figure out the compression algorythm or ask the programmers for the extraction tool.

		TakaIsSilly		Aug 9, 2001
			Just a polite guess. Read some docs about .LHA compression. Japanese have an fixation with that compression format ^^;. Also, just because it's a huge file, it is not necessarely a compressed archive. Games coded for both ST-V and Saturn have the tendency to be huge files. They're not compressed, they're just modified ROM images.

		whodailli		Aug 17, 2001
			well actualy if its a huge file an its a .dat then its most likely a mpeg....basicaly a movie file...

		CyberWarriorX		Aug 17, 2001
			Not necessarily. For example, in Langrisser III and DE, there are a couple of pretty big dat files. In III's case, a 12 meg one, and Langrisser DE's, a 4 meg. What are those huge files used for you might ask? Text. Graphics possibly as well. Amazing how wasteful NCS got when they decided to make games for saturn. Though for the most part, it seems alot of companies just use dat files for some kind of data compilation. Whether it be text, graphics, sound, etc. My best suggestion is just to go through the file with a good hex editor and see if you can find any headers or possibly any kind of pointer tables at the begining of the file. If you find a table, see if you can trace where the various entries are pointing to, and you might be able to figure out what kind of data you're dealing with. Cyber Warrior X

		RadSil		Aug 18, 2001
			A question to some people that might know... what file format has the header "LZ00"? LZH compression?

		ExCyber		Aug 18, 2001
			Looking at a description of the LZH file format, it seems that LZH files do not start with "LZ00" (it might appear somewhere in the header, but I'm not sure). The signature may signify some kind of custom format based on Lempel-Ziv compression, though. The Lempel-Ziv compression scheme is based on recognizing repeating blocks in a stream of data. A description of the algorithm can be found at: http://www.data-compression.com/lossless.html#lz For source code that decompresses Lempel-Ziv, gzip ( http://www.gzip.org... ) should have an LZ decompression routine, though it's probably for a specific implementation of LZ.

		TakaIsSilly		Aug 18, 2001
			Ah, that's the format I was talking about. LZH is also an implementation of those routines, and err... I saw free routines for it years ago. Anyway, try and find a dictionary section on the files. If it matches the LZH version, maybe you're lucky ^^;

		TakaIsSilly		Aug 18, 2001
			Ah! Here's that source code and texts I was thinking. It's 3 very influent modifications of the LZ and Huffman compression. http://programmersheaven.com/zone22/cat166/2261.ht...