0

I am trying to recover some backups from two old 9-track tapes. They were created ~1980 under RSTS/E version 6.

I have VMS 7.3 on a MicroVAX II and a functional TU80 tape drive. Both systems are fully functional so it is not a "Jurassic computing" hardware issue.

I have tried several strategies including BACKUP and EXCHANGE, but is is "no go" so far. The tape density is unknown, but likely 800 or 1600 given the age of the tapes.

Any suggestions would be appreciated.

Thanks in advance,

Kevin

Kevin McQuiggin
  • 1
  • I'd start with `directory` and `copy`. Mount the tape with `/override=identification` and list out the directory. (Note that a tape can have multiple files with the same name.) Tip: You can use `set magtape/rewind` to rewind the tape. IIRC, `show device/full` will display the density. – HABO Jul 16 '18 at 15:17
  • From the `retro-computing` tag: "Retro computing refers to the use of outdated hardware platforms (such as the Commodore 64 or BBC Micro), **usually for recreational purposes**." _(Emphasis mine.)_ Sigh. – HABO Jul 16 '18 at 15:28
  • Thanks for the reply. I tried this approach first. The tape has no recognized structure under VMS. It will $mount/over=id just fine but $dir fails. $sh dev mua0:/full after $mount shows the system default density, even if I $mount/density=800 first. – Kevin McQuiggin Jul 16 '18 at 15:29
  • Thanks for the retro-computing info, this is indeed a hobby! I have ~20 old DEC systems in the basement. This particular task is to help a friend restore his old grad school tapes! – Kevin McQuiggin Jul 16 '18 at 15:30
  • The spec's show that the TU-80 only supports 1600bpi. (It's been a long time since I had one. It was a leap down from the TU-78 I started with.) – HABO Jul 16 '18 at 15:45

1 Answers1

0

Might need RSX and FLX ? (File-explorer?)

If the mount/over=if worked, then it may have been ansi formatted no? Could it be a nameless file that you can grab with a straight copy? I may well be all wrong on this. $COPY MT: test.dat

$ Mount/foreign and DUMP to see what's out there with headers and tape-marks and so on?

There are free-ware tape-copy tools out there that can get raw block on disks for analysis. And I believe the latest LD has a virtual magtape driver as well allowing one to interpret a disk file as tape and visa versa?

Good luck! Hein

Hein
  • 1,453
  • 8
  • 8
  • Thanks Hein! I tried the DUMP utility but was unable to get it to work with the target tapes. I get a parity error on both of the tapes, so I now think that they may have been recorded at higher density than my old TU80 drive can read. As HABO noted, the TU80 only supports 1600 BPI. – Kevin McQuiggin Jul 17 '18 at 20:18
  • And I might add that I tested DUMP on some other known-good tapes, and I was able to read them just fine. I think that density is the culprit. Thanks all for the suggestions! – Kevin McQuiggin Jul 17 '18 at 20:18