Unknown Decompression Technique

thinkpadman

I've been going through a heap of ancient ZIP files circa 1994 or therebaouts from the old warez scene, finding a few things that aren't on WinWorld at all or a different version. While it's not ideal, some of it I doubt we will ever see originals for.

I found 4 ZIP files that claims to be for Aldus Persuasion 2.2 for example. Compared to 2.1 here the files are totally different and I suspect they've been compressed in some format.

First ZIP file contains: INSTALL.EXE (32 KB) and ALDSP22A.001 (1.3 MB)
The other three ZIP files just have ALDSP22A.002, 003, etc. for the file extensions and are of similar size. These files date back to 1993.

Under a Win for Workgroups VM, executing INSTALL.EXE does nothing but under DOS it states it needs to run under Windows.

I attempted to use HJ-Split, a small utility I've had for several years to join up 001, 002, etc. files but it didn't work for these.

Anyone recall after all this time what utility might have been used to "ZIP" it up in such a format?

SomeGuy

If it is a real installer, then it could be proprietary. Installers weren't tied to a standard algorithm, so they often tweaked it themselves for speed (important when extracting from floppy), and compressed data was usually in custom container files (installers have a few needs not commonly addressed by standard tools).

That said, this sounds suspicious as Aldus software usually used individual compressed files rather than merging them in to one single file.

Are there any identifying strings in the install.exe?

Also, if this was a custom archive, then the exe might be a 32-bit 95/NT executable.

thinkpadman

I'm sure it's used some backup program from that time for the purpose of saving over multiple floppies. I know it's not specifically Aldus related as I had a different title saved in the same way. INSTALL.EXE under Windows 95 only brings up a DOS prompt window and says it requires to be run under Windows. I cannot identify anything of use viewing INSTALL.EXE, apart from seeing:

It don't work!Termination Unsuccessful!'This program requires Microsoft WindowsU‰å1ÀšÒ  jjš’÷jšÊ÷jÿš} ÷	Àu h\hmj š˜	  š
  šÔ  1Àšä,  Éð        Runtime error   at  
 80x87 required
 80286 or 80386 required

I''ve tried MS-DOS 6.22's restore command and Central Point Backup 7.2 with no success.

When opening the files in hex, the files consisting start with:

.ppoint21.001...

where 001 is incremented. I'm currently installing PC Tools for Windows 2.0 and will try the floppy backup program in that. As you may have guessed, I'm was thinking this may have been related to a Central Point backup program of some sort.

All I did back then was use PKZIP in DOS for software backups.

02k-guy

^^^---EDIT: We posted at same time. So you are already doing that.

In the early 90s, splitting, compressing, fitting things on floppies was a normal ritual.

Everybody had a util to do that.
PKZip, Arj - you name it.

First thing is to look at the header of those files and see what the first 2, 3, 4 bytes say.

02k-guy

You just reminded me though: I have Aldus Photostyler 2.0 sitting in a dir here..

Not the same as Winworlds.

I do believe this is a retail rip of a 6 floppy set.

thinkpadman

02k-guy wrote:

In the early 90s, splitting, compressing, fitting things on floppies was a normal ritual.

Yeah I don't miss this at all from that era.

02k-guy wrote:

First thing is to look at the header of those files and see what the first 2, 3, 4 bytes say.

That's how the 001 file appears in hex.

02k-guy

Now that's interesting. Lots of repeating values. I guess it could have been right at some point in a graphics image.

thinkpadman

02k-guy wrote:

Now that's interesting. Lots of repeating values. I guess it could have been right at some point in a graphics image.

Makes sense, clip art maybe? Anyway, I still haven't made any progress so I'm giving it a miss unless a clue comes up.