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prowler 18 August 2010 01:00

DiskSqueeze questions

I have generated valid DiskSqueeze archives from ADF images of the Amiga Format Subscriber disks 81-87 and compared them with the invalid archives previously on the EAB File Server.

The new archives were prepared in WinUAE emulation by mounting each image in turn in DF0:, and running the DiskSqueeze v1.23 application.

Select Action: Pack
Select Device to Pack: DF0:
Is the disk using a mixed filesystem? No
Do you want to add a filelist to the archive? No
Do you want to add a File_ID.DIZ to the archive? No

Seven new archives were generated from the disk images, and the integrity of each archive tested OK.

The Image.dsq file extracted from each archive using the LZX command line tool was found to be identical with that extracted from the corresponding invalid archive.

Comparing the new, valid archives with the old ones showed them to be identical, except for twelve bytes at offset $1C (differences shown in bold type):


81.dsq        $1C  8B C5 0D 43 D0 29 A7 8A 0C F1 FB 10  Valid
530534 bytes        18 10 5B 94 D0 29 A7 8A 86 00 74 10  Invalid
929024 bytes
82.dsq        $1C  8B C5 2C 01 A0 30 E4 73 78 14 D6 24  Valid
836836 bytes        18 10 5B FA A0 30 E4 73 CC E8 8F 8D  Invalid
929552 bytes
83.dsq        $1C  8B C5 30 CF 5F 18 2E 05 59 1E F9 BF  Valid
793600 bytes        18 10 5C 58 5F 18 2E 05 EB 58 51 5F  Invalid
907376 bytes
84.dsq        $1C  8B C5 34 87 17 EF 38 89 4F B6 3D 53  Valid
788336 bytes        18 10 5C E2 17 EF 38 89 33 64 13 6B  Invalid
899984 bytes
85.dsq        $1C  8B C5 38 7B 62 49 33 80 07 DD 85 E8  Valid
820668 bytes        18 10 6A 5F 62 49 33 80 1B 38 6E E7  Invalid
926912 bytes
86.dsq        $1C  8B C5 3B 14 7E 49 42 B1 E6 01 0E 02  Valid
769920 bytes        18 10 6A CD 7E 49 42 B1 69 40 B8 77  Invalid
916352 bytes
87.dsq        $1C  8B C5 3D 45 88 B8 38 5C A7 BE 9A 27  Valid
773004 bytes        18 10 6B 4F 88 B8 38 5C 60 D0 65 D4  Invalid
921632 bytes

To enable me to fix similar archives in the future, could you please advise me of the purpose of these bytes in the file header?

I assume that the first four bytes are the file's date and time stamp, as they increase progressively for both the valid and invalid archives.

The four middle bytes I assume are the files' checksums, as they don't change, but I'm mystified about the last four bytes and I'm assuming that it is those which are breaking the invalid archives.

Thanks in advance for any help you can offer.

exoticaga 18 August 2010 06:18


Originally Posted by prowler (Post 693087)
Hi dirkies,

There were some DiskSqueeze archives on the EAB File Server which were supposedly Amiga Format Subscriber disks 81-87. They are no longer there, but I could upload an archive containing them to the Zone for you.

Check out these instead. since many have problems with them also.

Collection > Coverdisk > Amiga User International > AUI Disks (Disk Squeeze Compressed)

They do work even the subscribers disks here do work, and i do remeber will unpack to floppy and be 1:1 identical binary comparision. This is when i had amiga hardware etc to do that with, only have pc winuae now.

I did check aminet for and found no script to convert dsq to adf. Maybe dirkies could update his program to do this.

Was the problem becuase extended disks as with the AUI seconds disk 2 Look at the AUI diskqueeze disks following the above path on the eab server. There is a seperate AUI thread for problems others have with those on the forum somewhere.

Dirkies if you can find a way to convert any disk converted with disqueeze sofwtare to adf and extended adf that would be nice. A script or a script for disksqueeze v1.23 or included in disqueeze update for this would be a help for many users. :)

prowler 18 August 2010 21:33

This evening, when I resumed my investigation into the discrepancies between those bytes in the headers of the 'valid' and 'invalid' DiskSqueeze archives, I found that I could actually extract the 'invalid' archives without making any changes to them! :shocked

I had intended to find out for sure which bytes were preventing the 'invalid' archives from even being recognized, but when I retested the first archive before making any changes to it, it tested OK, and so did all the others!

I can only guess that using the program yesterday to generate fresh archives somehow completed the installation process and got the decompression routines working properly. :confused


Originally Posted by exoticaga (Post 693434)
Check out these instead. since many have problems with them also.

Collection > Coverdisk > Amiga User International > AUI Disks (Disk Squeeze Compressed)

Well, now that I have got the DiskSqueeze program functioning properly, I am in a position to check and unpack other DiskSqueeze archives on the EAB File Server.

@TCD: Are there any others which need looking at? :nervous

TCD 18 August 2010 21:40

Nope, seems like AF and AUI are the only ones that feature this format :)

prowler 18 August 2010 21:46

Okay, thanks. I'll go and grab the AUI DiskSqueeze archives now, and I'll work on them tomorrow.

exoticaga 18 August 2010 22:04

Prowler its the AUI disk 2's that are the problematic ones. They are packed with disksqueeze using diskspare device or similar. These would be extended adf if convert them ok.

prowler 18 August 2010 22:13

Will the DiskSqueeze program use the diskspare.device (just downloaded it from Aminet) if it is placed in DEVS: ?

exoticaga 18 August 2010 22:23

Better to look at it's guide. Could be something like 81cyl with 11 or 12t or something similar, the guide will tell you. I did mention a AUI thread here didn't i that has the details if the guide is of little help.

prowler 18 August 2010 22:37


Originally Posted by exoticaga (Post 693612)
I did mention a AUI thread here didn't i that has the details if the guide is of little help.

Is this the thread you mean?

exoticaga 18 August 2010 22:44

Ah there you go, mm maybe there is two of them, threads that is. There is another for someone else who had problems. But the info mostly you need is there by the look of it ;)

prowler 18 August 2010 23:01

I've also found these two posts here and here.

exoticaga 18 August 2010 23:22

Use the mountlist there see how it goes, i'm sure it should be correct or near correct :)

prowler 18 August 2010 23:35

The first thing to do is use DiskSqueeze (with the diskspare.device installed) to test the archives. If they're OK, then I'll start thinking about how to write them back to real disks or extended ADFs.

exoticaga 19 August 2010 00:25

Only way i guess is with a real amiga floppy drive and then to extended adf. I did try with winuae time ago didn't work out for some reason, those posts say more.

prowler 19 August 2010 00:44

Thanks for your help with this, exoticaga. :great

Right, I've downloaded all the AUI_xxx-DS0.DSQ files from the AUI Disks (DiskSqueeze compressed) subfolder, plus the 041, 042, 046, 049, 077, 079, 081, 083, 085, 089, 091, 099 and 103 archives, because these are not included in the parent folder in ADF format (and that is what this unpacking is for, after all).

Incidentally, there are a lot of duplicate archives in this subfolder, as well as in the parent folder.

The odd-numberred archives above should unpack without any difficulty to standard 880K ADF files, and these I shall upload tomorrow.

exoticaga 19 August 2010 02:01

Yes that happened recently with server resort, thought i'd leave TCD to figure that out :D

If you do find a way to convert the 2nd disks to extended adf 1:1 using winuae i'm all ears. As i have no amiga hardware for a ong time now, reason why they are stil in ds0 dsq archives unable to convert. Aminet i did cjeck but needs updating to make searching easier there. Hard to track down items even with using the drop down selection lists.

How will you test that the disk2 are bit exact to the dsq disk2 after unpacking it to amiga floppy ?

Maybe dirkies is working on an update or a script add in for doing this with winuae and disksqueeze to adf normal and extended. Or he's quiet because he out enjoying the summer sun while it's there :nervous

dirkies 19 August 2010 13:48

I saw this thread, must dig into the code, but afaik you can disksqueeze to a ramdisk and then adf from there, although I have no experience in creating adf's, after all I only used real amigas for ...using Amiga software :D

Toni Wilen 19 August 2010 20:13


uaeunp.exe AUI_104-ds0.dsq\image.dsq.dir image.dsq.adf
Image.dsq.adf extracted, 983040 bytes

uaeunp.exe Image.dsq.adf
    [DIR] ----RWED 1997/02/05 15:28:19          Archives
      2700 ----RW-D 1997/02/02 19:10:44 53678A41 disk.info

uaeunp.exe Image.dsq.adf\archives
    [VDIR] ----RWED 1997/02/02 15:54:32          AUIApr97a.lzx.DIR
    [VDIR] ----RWED 1997/02/02 19:01:14          AUIApr97b-a.lzx.DIR
    [VDIR] ----RWED 1997/02/02 19:01:36          AUIApr97b-b.lzx.DIR
    [VDIR] ----RWED 1997/02/02 15:13:12          AUIApr97c.lzx.DIR
    291230 ----RWED 1997/02/02 15:54:32 F397D4CA AUIApr97a.lzx
    186517 ----RWED 1997/02/02 19:01:14 9DFAAF82 AUIApr97b-a.lzx
    268054 ----RWED 1997/02/02 19:01:36 865E0DE6 AUIApr97b-b.lzx
    212481 ----RWED 1997/02/02 15:13:12 3134C5EB AUIApr97c.lzx


Of course diskspare.device and mountlist required to read these inside Amiga environment.. (12 sectors per track, 80 cylinders)

Or use some Amiga disk image mounter device with correct mountlist, no need for diskspare.device in this case.

prowler 19 August 2010 21:16

Thanks, Toni! I'll try that method of extracting the archives. :)

@TCD: In the meantime, I have extracted the thirteen Disksqueeze archives I mentioned above which are not duplicated in ADF format in the parent folder. I'll be uploading those to the Zone for you shortly. :great

Edit: Zoned! :D

prowler 19 August 2010 22:59

@TCD: Thanks to Toni and his uaeunp.exe command line program, I have now converted all 21 of the AUI_xxx-ds0.dsq archives to 12 sectors per track, 80 cylinders ADF images (983040 bytes). :)

I am uploading an archive to the Zone for you now...

This completes the .DSQ to .ADF conversions for the EAB File Server coverdisks archive. :great

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