Tatung Computer Forum

I have a disk which i can get a directory from but of the 5 listed programs I'm only able to copy 1, clearly the disk is damaged in some way.

If the data is corrupt then there's probably not much I can do, but is it possible that some kind of cleaning might help, and if so how would I do this?

The disk is 'Communications with View Data by KUMA'. I haven't seen a dump anywhere. I also have the manuals and not seen them anywhere either, so if someone can confirm that they need scanning I'll sort that out.

I will have a look and see if i have a copy of it from a recent acquisition. Probably not as they were mostly games.

A scan of the manual would be good to add to my server repository

I have had a quick look, but sadly ViewData by Kuma is not on any of the new disks I got recently.

I've also had issues with my old 3 inch discs. There are a few things you can do.

It may be your specific drive that has an issue with this particular formatted disc, so sometimes it's worth trying the disc in another machine. The alignment may be out, although if this an original commercial disc this is unlikely to help.

If you run DISCMOD (by Kuma) you can check which tracks and sectors are readable to get an idea of the extent of disc corruption. But take care, as the Manual includes a reminder that you "can destroy the information stored on the disc which you are investigating".

DISCMOD allows you to interrogate the Directory entries so you can see if there are any backup deleted entries that can be retrieved. Commercial discs often include older program versions that have been deleted that are nevertheless copied by the disc duplication process. Have a look at the DISCMOD manual for details about changing the first byte of the File Control Block to retrieve a deleted file. If you see a file name with E5 in front of it, it's been deleted and can often be retrieved if the original sector information has not been overwritten. It's possible an older deleted file resides on an area of the disc that's not corrupt so you can attempt to get it back.

I've found that various disc checking programs available on my Amstrad 6128 can determine the format of each track to see if sectors are corrupted or appear to have unusual numbers (and/or sizes) that will stop normal disc copying from working. Whilst I've had success with retrieving information from corrupted discs when the sectors are accessible, I've had no success dealing with missing address marks. As far as I know, there is no software on the Einstein that can tell you if the problem is that the address mark is missing, which is why I check this with my Amstrad.