> On 08/10/2016 07:42 AM, Al Kossow wrote: > >> congratulations, you reinvented .tap format.. badly. >> >> how did you handle unreadable blocks.
I didn't. I didn't have any unreadable blocks. I have CCTs that I made (and sometimes got elsewhere) going back to the eighties. No read errors. I simply needed a way to a) get a copy that I could use to later write a new tape, with original records, and b) extract the content when the original minicomputers were gone. And that format worked for that, and saved all my data. Incidentally it made for an easy way to create a DLT tape duplicator (via disk) later, when I suddenly needed one. In short, it served my purpose perfectly and didn't need any research, finding software somewhere, port it, blabla. It's a very simple format which can be implemented and tested in a day, and does the job, unlike trying to e.g. 'dd' a tape. I don't even need to look up the 'protocol' if I need to write a new tool later. It can't possibly be simpler, and yet it does the job. On 10 August 2016 at 17:43, Chuck Guzis <ccl...@sydex.com> wrote: > Additionally, how was the metadata handled? (i.e. information about > equipment used, paper labels, maybe a photo of the tape reel itself?). Paper labels are short. The output file of the above process was stored together with a 'label file', a short text file with what's written on the label. And I would sometimes add some extra info if I looked through the content (with some other software I wrote, and depending on what the original format was). I didn't see any need for storing info about the physical tape itself, e.g. 1600 or 6250 bpi, or reel size. I have yet to find a need for that. When I could, I would note (with the label) what kind of software was used to write the tape (e.g. VMS ANSI tape, or Norsk Data backup-system format, or whatever). But the important aspect was simply to have a disk file in a format which reflected the original written tape, so that the disk file itself could be used to later extract the content, with other tools. That can't be done with any format that doesn't store the original record information, except for record-less formats like 'tar' (record-less in the sense that the physical record size isn't part of the format, unlike e.g. ANSI tapes). For my purposes I also haven't found any need of further equipment information, e.g. which tape drive was used to read the tape (I only own one anyway, and I can't see that it would make any difference if I had more than one). And I also don't need info about what kind of drive was used to write the tape, there's no way to find out anyway (other than investigating what was installed at each site at the time the tapes were originally written).
