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Recovering an Unistride QIC tape...

jdreesen

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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.

Jos
 

kgober

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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.
 

jdreesen

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

Chuck(G)

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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.
 

Al Kossow

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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
-r-
 

jdreesen

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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.
 

Chuck(G)

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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.
 

jdreesen

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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
 

jdreesen

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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.
 

jdreesen

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Yep, tried that too. I may be able to image an existing Unistride installation ( i.e. image the MFM disk ) , however the install tape would have been nice...
 

jdreesen

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Switzerland
So I have gotten another Unistride 2.1 QIC tape in my possession. Alas : the drivebelt is too loose and sticks to the tape. How to separate them savely ?
I have a know-good drivebelt to start reading, but I first need to separate old belt / magtape....

( Tape has been baked...)
 
Last edited:

MattisLind

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The method I have been using succesfully with around 100 TU58/DC100 and a few DC300 is to use a heatgun at lowest temperature. Perhaps 50 degrees or a little bit more.

Aim it at the drive belt at some distance and move along the drive band. The driveband then shifts from a matte finish to a more glossy finish. Very often they snap off when doing this. When all of the drive belt has the glossy finish I gently remove the driveband from the tape.
I have never had the magnetic media come lose.

There will be some sticky residue left on the tape which I remove using Isopropanol and a q-tip. Also very gently so no oxide is rubbed off.

It was Rik Bos that learnt me the heating procedure and I never had any problems with it.
 
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