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Revision as of 21:52, 20 May 2020 by TArntsen (talk | contribs) (Floppies (backup) format)
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Nice! It's good to see this documented. I wrote a Unix tool to read backup-system format CCTs back in 1998, specifically for IRIX on an SGI system I used for reading my old ND backup CCTs. I'll read through the description to see if it all matches what I did, or not.. a quick check looks very familiar. Thanks for adding the page. -- TArntsen (talk) 11:09, 19 May 2020 (UTC)

Floppies (backup) - different format?

So I have a lot of floppies which are labeled "backup" and are in sets (1 - n), but they are not normal ND filesystem floppies, and not backup-system volume format. Any idea what kind of format they are, and where it might be documented? Unfortunately, I don't know which tool was used to make the backup. Torfinn (talk) 11:42, 19 May 2020 (UTC)

There's a faint bell ringing, but I'm not sure. I could take a look at images if you wish. --TArntsen (talk) 11:52, 19 May 2020 (UTC)
Ok, I've sent you a sample. Torfinn (talk) 12:18, 19 May 2020 (UTC)
Hopefully you received the decoded images - unless they were too large for the mailbox. Not sure where the format should be documented. I'm pretty sure I used a backup tool back in the eighties which would write something that could have been that format, but if that would have been considered a part of the backup-system suite I'm not so sure about. The format is basically as follows: Each volume file has an 8-page (16K) header with a dir name and a label, a volume number and the total number of volumes, and a list of page numbers which tells where each of the 2KB pages following the header should be written. Plus a little extra metadata. A feature of the format is that you could take any of the volume files in any sequence and simply update the output image, when all the volumes have been applied you have a disk image in ND format. --TArntsen (talk) 16:39, 20 May 2020 (UTC)
I got the images - thanks (Gmail, so large-ish files are no problem)! ND–60.250.1 EN BACKUP USER GUIDE Chapter 9 lists some stand-alone programs: DISC-TEMA-H, WINCH-TO-FLOPP / FLOPP-TO-WINCH, MCOPY-TANB, DIR-BACKUP. Of these, only WINCH-TO-FLOPP copies to floppies, as far as I know. Perhaps that was the program used? Torfinn (talk) 18:28, 20 May 2020 (UTC)
It's almost certainly WINCH-TO-FLOPP, the format I deduced matches the description (50 char max string w/date, as well as the other information provided). I'll add the format description to that page later. --TArntsen (talk) 21:52, 20 May 2020 (UTC)