Found broken floppies of these (Part 2)

[dirkies]

added that broken Powerstyx from Phoenix ISOs here (POW-STYX.DMS)
ftp://ftp.magix.ws/~Public_User_Uploads/dirkies/

remember the BS1 disk is an MFM disk that normally required nibble mode to copy on a normal Amiga.

[prowler]

Thanks for the POW-STYX.DMS file.

I have uploaded a valid CCS Music collection Nr 1.adf dumped from the 5¼-inch disk to The Zone for you.

I have got the bad sector count on the Black Label Demo Disk 8.adf down to twelve by trying it in some other drives. I think the remainder will need to be recovered with KryoFlux; they are very persistent.

[dirkies]

yeah, another one saved, thanks dude!

Now get that kryoflux up & running

[prowler]

Originally Posted by prowler

I have got the bad sector count on the Black Label Demo Disk 8.adf down to twelve by trying it in some other drives. I think the remainder will need to be recovered with KryoFlux; they are very persistent.

I selected the disk drive which gave the least bad sectors on the Catweasel and hooked it up to the KryoFlux, but I couldn't get the bad sector count down any further.

None of the remaining bad sectors is unreadable, but most are badly corrupted. This disk is going to be very difficult to recover fully.

[dirkies]

Originally Posted by prowler

I selected the disk drive which gave the least bad sectors on the Catweasel and hooked it up to the KryoFlux, but I couldn't get the bad sector count down any further.

None of the remaining bad sectors is unreadable, but most are badly corrupted. This disk is going to be very difficult to recover fully.

That's OK Prowler, but maybe with other drives and my 3.5 "backup" it may be possible to restitch/ressurect this disk, it's an oldskool collectible!
So in other words, why not try harder?

[Asle]

We would welcome it, indeed.
Also, thanks to you both, the CCS musicdisk is now complete.

Cheers
Sylvain

[prowler]

Originally Posted by dirkies

That's OK Prowler, but maybe with other drives and my 3.5 "backup" it may be possible to restitch/ressurect this disk, it's an oldskool collectible!
So in other words, why not try harder?

All except three of those bad sectors are even worse on your "backup" disk.

Don't worry, I've still got a few tricks up my sleeve, but this one will be a tough nut to crack.

In fact, I had tried only one of the remaining three 5¼-inch drives before getting the KryoFlux set up for the PowerStyx disk. (More about that in the other thread.)

Just because that particular drive gave the best result so far with the Catweasel, it doesn't necessarily mean that it will perform better than all the others on the KryoFlux.

In fact, the unique characteristics of each disk drive give significant variations in performance with different controllers, so that it may even still be possible to recover some of these bad sectors on a PC running ReadADF or the Registered version of Disk2FDI!

[dirkies]

Originally Posted by prowler

All except three of those bad sectors are even worse on your "backup" disk.

Don't worry, I've still got a few tricks up my sleeve, but this one will be a tough nut to crack.

In fact, I had tried only one of the remaining three 5¼-inch drives before getting the KryoFlux set up for the PowerStyx disk. (More about that in the other thread.)

Just because that particular drive gave the best result so far with the Catweasel, it doesn't necessarily mean that it will perform better than all the others on the KryoFlux.

In fact, the unique characteristics of each disk drive give significant variations in performance with different controllers, so that it may even still be possible to recover some of these bad sectors on a PC running ReadADF or the Registered version of Disk2FDI!

Prowler, you're a star already IMHO, the more you can recover, the more my nostalgia-stamina improves
Keep keeping up the good work for me and the nostalgic old-fart community

[prowler]

I have discovered why the Black Label Demo Disk 8 is proving to be so difficult to recover.

There is a stain on the lower side (Head 0) of the disk recording surface approximately 8mm in diameter and centred 15mm from the outer edge of the aperture, i.e. of suitable size and position to have been causing bad sectors in the range of tracks 22-43 on the lower side of the disk noted on the sleeve ten years ago.

Cleaning with isopropyl alcohol applied with a cotton bud reveals that the contaminant has caused some permanent damage to the recording surface - mainly in the central 3mm diameter region and, to a lesser extent, at the circumference.

The disk is none the worse for having been cleaned, but neither is it any better.

Under the circumstances, it is very unlikely that I will be able to salvage the remaining data from this disk.

The best way forward now is for me to discover which files are damaged and list the details here in an attempt to find duplicates with which to repair the disk image, and this I will do tomorrow.

[prowler]

I've just noticed this:

Originally Posted by dirkies

Amiga Multitasking Demo (Commodore) in English < maybe someone knows the exact name? Prowler?

I have only the German version (not the original disk; I downloaded it).

The disk image is Multitasking-Demo.adf, but the volume name is copy2 of CLI10.

CBM OS1.2/1.3 Multitasking Demo from 1985 (German)

Bootable multitasking presentation disk. (Press Return, F1, F2 or F3 when prompted.)

It starts off with an older man sitting behind a desk hanging on the telephone. Later, you see "Fred the Baker" playing with his yo-yo while he waits for his PC to finish one task before starting the next, and "Rose Thornbush" with her multitasking Amiga running one task in the background while she's getting on with the next...

Edit: Is this similar to the one you're seeking?

[dirkies]

bad news for the black label disk
and yes, the multitasking demo is the one I remember, mine was in English and also saw a Dutch one, but German is fine for now too Can't believe this is not in TOSEC

[prowler]

Originally Posted by dirkies

yes, the multitasking demo is the one I remember, mine was in English and also saw a Dutch one, but German is fine for now too Can't believe this is not in TOSEC

It's in The Zone for you.

Originally Posted by dirkies

bad news for the black label disk

It's not over yet.

The disk has 12, as yet, unrecoverable bad sectors caused, presumably, by lasting damage resulting from that stain which I have now removed.

While I think it may still be possible for me to salvage something from this disk by other means I'll continue working on it.

In the meantime I have reconstructed the bad sector headers, replaced the bad data with "BAD!..." strings and recalculated the checksums, so that all files now copy out of the disk image without errors, but there are five bad files: 5 (3 bad sectors), 1 (1 bad sector), 3 (3 bad sectors), 7 (1 bad sector) and 4 (4 bad sectors). This is the best you'll get for now.

I'll attach this image here until I have something better with which to replace it.

[Asle]

ACF demo is here (file 7).

[prowler]

Originally Posted by Asle

ACF demo is here (file 7).

Thanks, mate! Indeed, that file is of the correct size.

If that is a valid copy of the 7 file, then that will fix one of the bad sectors (Disk Block 729).

I have reconstructed some of the missing data today by comparing captures I have made so far of the bad sectors to separate valid data from the corrupted, but I have not yet made any progress on Disk Block 729, so that will be of great help.

Edit1: Here is a listing of the root directory of the Black Label Demo Disk 8 to help find good copies of the damaged files, which are identified in bold red type.

Directory "df0:"
.fastdir                    1180 ----rwed 07-Mar-87 02:18:15
DemoAction.ROTACT            540 ----rwed 07-Mar-87 02:21:10
DemoObject.ROTOBJ            824 ----rwed 07-Mar-87 02:21:12
Em.ROTOBJ                    440 ----rwed 07-Mar-87 02:21:13
RobotHead.ROTOBJ            1136 ----rwed 07-Mar-87 02:21:13
4                          58052 ----rwed 07-Mar-87 02:21:32
c                            Dir ----rwed 07-Mar-87 02:20:58
ShakeHead.ROTACT             348 ----rwed 07-Mar-87 02:21:45
tetrahedron.ROTOBJ           168 ----rwed 07-Mar-87 02:21:47
Tube.ROTOBJ                  776 ----rwed 07-Mar-87 02:21:49
TubeRoll.ROTACT              716 ----rwed 07-Mar-87 02:21:52
Tumble.ROTACT                440 ----rwed 07-Mar-87 02:21:56
Twirl.ROTACT                 720 ----rwed 07-Mar-87 02:21:58
Yrotation.ROTACT             348 ----rwed 07-Mar-87 02:22:00
3                          26908 ----rwed 07-Mar-87 02:25:10
d                            710 ----rwed 07-Mar-87 02:19:12
1                          19980 ----rwed 07-Mar-87 02:28:59
libs                         Dir ----rwed 07-Mar-87 02:17:58
6                           7504 ----rwed 07-Mar-87 02:20:24
glider.s                     339 ----rwed 07-Mar-87 02:25:14
platte.s                     189 ----rwed 07-Mar-87 02:25:16
2                           3220 ----rwed 07-Mar-87 02:32:01
pyramide.s                    83 ----rwed 07-Mar-87 02:25:20
5                          71808 ----rwed 07-Mar-87 02:36:26
Devs                         Dir ----rwed 07-Mar-87 02:16:55
HellDat2                  128072 ----rwed 07-Mar-87 02:21:09
7                         176048 ----rwed 07-Mar-87 02:18:07
8                          71948 ----rwed 07-Mar-87 02:29:54
9                           4000 ----rwed 07-Mar-87 02:22:39
a                           2084 ----rwed 07-Mar-87 02:22:44
b                         167244 ----rwed 07-Mar-87 02:23:42
S                            Dir ----rwed 04-Mar-87 03:31:32
.info                         16 ----rwed 13-Jun-87 21:46:32
29 files - 4 directories - 1510 blocks used

Edit2: I have found the Prophets-GuruMastersIntro here (File 5?).

Edit3: Yes, that's the right one! Another three bad sectors fixed!

I'll upload an updated disk image tomorrow.

[prowler]

Thanks to Asle and his website, I have been able to fix four bad sectors on Black Label Demo Disk 8 by importing ACF-FutureIntro09 and Prophets-GuruMastersIntro to replace the damaged files 7 and 5, respectively.

Disk Blocks 574, 604, 623 and 729 are now fixed, and there are now just 8 bad sectors in the attached disk image.

In the meantime, the search for valid files to replace the damaged ones continues, as does my effort to salvage the bad data blocks...

[prowler]

Earlier this evening, I fixed Disk Block 797 by comparing a good capture of it with two other good captures and making selected changes until the original checksum was matched.

This would now appear to be the only method left open to me to fix the remaining bad sectors on this disk, so I will continue with it, when I have time, until either it is fixed or it looks hopeless.

Disk Block 797 is the third of four bad sectors in the 4 file. I'm fairly confident that the result is good, but it will not be possible to check it until the whole file is fixed.

I have a very good capture of Disk Block 845, which is the first bad sector in the 4 file, but, as yet no other closely matching capture to compare it with.

I also have two very closely matching good captures of Disk Block 815 (the second bad sector in the 4 file), but there are insufficient differences between them to make a fix possible, so more captures are needed.

Disk Block 778 is both the 4 file's last bad sector and EOF. I have recovered only about half this block so far.

The other bad sectors are in a much worse state, but there's still hope. After all, the fewer the bad sectors remaining, the easier it gets by being more focussed... and now there are only seven!

[prowler]

Once again, earlier this evening, I fixed another bad sector.

This time it was Disk Block 845, by making a 1-bit change after comparing the very good capture I mentioned yesterday with another I conjured up today.

Six to go now!

[dirkies]

woohoo, this starts to read like an addictive detective story

Keep trying Prowler, I am sure this will result in some near perfect restoration project

[prowler]

I couldn't rest with Disk Block 815 looking so recoverable, so I grabbed a few more captures until I had another three with a few more mismatches and set to work...

To start with, I was looking at a total of 28 mismatches between two or more of five captures, and by a process of elimination including looking for similar code in other parts of the same file, weighing the probabilities according to how many captures contained each of the candidate bytes and comparing the current and target checksums for each MOD(4) column, I eventually made just 17 1-bit changes to my original capture to match the target checksum and thus fix it.

Originally Posted by dirkies

woohoo, this starts to read like an addictive detective story

Let's hope it continues that way. To put today's achievement into perspective, Disk Block 797 required 7 1-bit changes, and Disk Block 845 just 1!

However, the disk blocks I have fixed so far plus those fixed earlier by importing valid files to replace the damaged ones are near the edges of the area covered by the stain and least affected, but it's about to get a whole lot more difficult because the remaining five (Disk Blocks 642, 661, 691, 711 and 778) are in the central area and are worst affected. For example, I don't, as yet, even have a target checksum for Disk Block 711.

Originally Posted by dirkies

Keep trying Prowler, I am sure this will result in some near perfect restoration project

As long as I can make measureable progress, I will keep trying, but I wish I had as much confidence as you!

I shall be taking a short break from this task from tomorrow, because a space has finally been cleared where I can set up a workstation to build a PC and leave it set up until I can dump an image of an old Kyocera KC 30B hard disk which has travelled all the way from Salzburg for the occasion.

[dirkies]

Hey Prowler, I think you have the English C= multitasking demo as I noticed in an older thread you recovered this disk already (I FOUND THE EXACT NAME!):

Amiga 500
The Very First
English Version
PN: 380921-02
(c) Commodore 14.07.87

Would love to see this again, walk down memory lane...