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Recovering an Unistride QIC tape...

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    Recovering an Unistride QIC tape...

    I have at my desk an Unistride 2.1 distribution tape, in a QIC-24 format. This is a Unix for the Sage/Stride 4xx systems, standard QIC drive for these systems was an Archive 5945L
    I read this tape on a Linux box with a Wangtek 5150ES SCSI streamer twice , and obtained the identical binary blob of ca. 6MB, no errors reported.
    However the resulting binary blob reveals no readable strings inside.

    What am I overlooking ?

    BTW I have recovered around 70 original Sage/Stride software distribution floppies, in addition to Unistride. If anyone is still messing around with these I can put them online.


    Did the tape contain only that singe 6MB file, or did other files follow? For a Unix distribution I'd expect a root file system image followed by dumps of any other file systems (e.g. /usr). If the system doesn't natively have utilities to copy from tape to disk, I'd also expect such utilities (and a boot block if needed) prepended at the start of the tape.


      Just that file. But there are separate floppies with boot code-boot block, root file system and (MFM-)harddisk-partitioning.


        Perhaps you could post a segment (or the entire file) and elicit some opinions.
        Reach me: vcfblackhole _at_ protonmail dot com.


          I've put it up at
          (That is the raw output from linux' dd if=/dev/tape... )


            My initial impression with a quick look is that your file is notable for the lack of 00 bytes. Lots of FF bytes, however, so my first impulse would be to take the ones' complement of the data and see if the result makes more sense. I suppose it could also be possible that this data has been run through some sort of compression.
            Reach me: vcfblackhole _at_ protonmail dot com.


              bingo! it's 1's compliment cpio file of the root file system

              -rw-r--r-- 1 root _lpoperator 150 Aug 4 1987 .login
              -rwxr-xr-x 1 root _lpoperator 91 Aug 4 1987 .profile
              -r--r--r-- 1 root wheel 19178 Jan 12 1988 Changelog
              -r-xr-xr-x 1 root _lpoperator 7002 Dec 17 1987 Config
              -r-xr-xr-x 1 root _lpoperator 1681 Mar 27 1987 Update
              -r-xr-xr-x 1 root _lpoperator 18064 Dec 17 1987 bin/cat
              -r-xr-xr-x 1 root _lpoperator 21474 Dec 7 1987 bin/chgrp
              -r-xr-xr-x 1 root _lpoperator 19256 Dec 7 1987 bin/chmod
              -r-xr-xr-x 1 root _lpoperator 21470 Dec 7 1987 bin/chown
              -r-xr-xr-x 1 root _lpoperator 14482 Sep 22 1986 bin/cmp
              -r-xr-xr-x 1 root _lpoperator 19422 Dec 7 1987 bin/cp
              -r-xr-xr-x 2 root _lpoperator 37866 Jun 1 1987 bin/cpio
              -r-xr-xr-x 2 root _lpoperator 37866 Jun 1 1987 bin/cpio5120 link to bin/cpio
              -r-xr-xr-x 1 root _lpoperator 20006 Dec 17 1987 bin/dd
              -r-xr-xr-x 1 root _lpoperator 37794 Apr 14 1987 bin/diff
              -r-xr-xr-x 1 root _lpoperator 5540 Sep 22 1986 bin/echo
              -r-xr-xr-x 1 root _lpoperator 8962 Sep 22 1986 bin/expr
              -r-xr-xr-x 8 root _lpoperator 61 Mar 18 1985 bin/false
              -r-xr-xr-x 2 root _lpoperator 41376 Dec 15 1987 bin/rshell
              -r-xr-xr-x 1 root _lpoperator 26296 Dec 17 1987 bin/ls
              -r-sr-xr-x 1 root _lpoperator 15248 Apr 16 1987 bin/mkdir
              -r-xr-xr-x 1 root _lpoperator 68772 Jun 1 1987 bin/dis
              -r-xr-xr-x 1 root _lpoperator 14482 Sep 22 1986 bin/pwd
              -r-xr-xr-x 1 root _lpoperator 19554 Dec 15 1987 bin/rm
              -r-sr-xr-x 1 root _lpoperator 13644 Sep 22 1986 bin/rmdir
              -r-sr-xr-x 1 root _lpoperator 29396 Dec 15 1987 bin/su
              -r-xr-xr-x 1 root _lpoperator 2060 Sep 22 1986 bin/sync
              -r-xr-xr-x 1 root _lpoperator 31606 Mar 16 1987 bin/tar


                I would expect there to be /usr on the next file. you did do the dd with the no-rewind tape device?


                  That was too easy!
                  Reach me: vcfblackhole _at_ protonmail dot com.


                    Originally posted by Al Kossow View Post
                    I would expect there to be /usr on the next file. you did do the dd with the no-rewind tape device?
                    I did, the next file immediatly returned an error. I assumed it was EOT, looking at the remaining tape in the cartridge.
                    I'll check again tomorrow if there is more on the tape.


                      Are you certain that your drive is reading the correct format? A single QIC-24 track is about 6MB. Do any of the other tapes that you have show more than 6 MB? (should show up to 60).

                      Just a thought.
                      Reach me: vcfblackhole _at_ protonmail dot com.


                        That was the second thing i wondered about. A DC600 cartridge in QIC24 format should, as you said, have 60MB. Yet my tape is at the end after just 6.5MB...
                        The SCSI tapedriver in Linux should recognize the tapestandard automatically, that should not be the issue. Anyhow reading the tape with a QIC02 drive yielded the exact same result.

                        Yes, there are more files on the tape, i can read around 500KB extra, then it spits out errors due to mechanical damage to the tape. Must have been wrinkeled at some time...

                        Some more /bin files, not a single /usr file though


                          Do you have any other cartridges to look at? Nominal capacity per track of QIC24 is about 6.6MB per track, which makes me suspicious.
                          Reach me: vcfblackhole _at_ protonmail dot com.


                            No other QIC24 tapes around....
                            The Wangtek has no issues reading 150MB tapes at full capacity.

                            Reading some of the recovered files reveals that there should be at least 4 tapefiles....too bad.
                            Can't sent it to someone else as it is not my property.


                              Too bad--have you tried skipping forward a tapemark (use mt) on the non-rewind device? Sometimes (rarely) you can skip over bad spots
                              Reach me: vcfblackhole _at_ protonmail dot com.