Help reading a 9 track tape

[Jay Jaeger]

Yeah, well, the first part is the hard part - setting it all up and 
making recording.  The second part is more or less trivial, once the 
software was done.

One of the 1410 tapes had a persistent parity error - that one I was 
able to figure out from knowledge of the machine, instruction set, etc.

JRJ

On 8/5/2021 8:14 AM, Paul Koning wrote:
> Perhaps the work could be split up: reading the track waveforms is the one step that requires special hardware (and the skill to handle the tape with minimal damage).  Given a collection of recovered waveforms, the data recovery can then be done by anyone.
> 
> 	paul
> 
>> On Aug 5, 2021, at 8:39 AM, Jay Jaeger via cctech <cctech at classiccmp.org> wrote:
>>
>> I know Paul well (we were contemporaries at U. WI).  He does not do that very often.  He did not indicate any issue with a fire at the building that contains his collection when I last spoke with him.
>>
>> He does not actually read "blocks".  He reads the tape in an *analog* fashion, and then processes the results with software.  That is how he recovered the IBM 1410 system tapes and diagnostics, for example.
>>
>> To be honest, I doubt that this content would be such that he would be likely to volunteer.
>>
>> JRJ
>>
>> On 8/4/2021 3:11 PM, Van Snyder wrote:
>>> Paul Pierce <prp at teleport.com <mailto:prp at teleport.com>> read some 7-track and 9-track tapes for me about twenty years ago. He was in Portland, OR at the time. His "lab" was on the east side of the Willamette river, so maybe it didn't get burned down.
>>> I don't know whether he still has a setup to read tapes. His software would read blocks forward and backward, including the parity frames, and make corrections.
>>> Van Snyder
>>> On Wed, 2021-08-04 at 09:25 -0500, Jay Jaeger via cctech wrote:
>>>> James, I am located in Madison WI.  I would need to fire up my SCSI 9
>>>> Track drive (software on Linux) and test it as I have not used in a
>>>> couple of years, but I have done recovery of old tapes from this era
>>>> before, and have a primitive setup for "baking" tapes before trying to
>>>> read them.
>>>>
>>>> Assuming my HP 9 track is still happy, I can produce AWS format tape
>>>> images, raw block files and extract individual files (translated into
>>>> ASCII if that is desirable).
>>>>
>>>> I don't remember exactly the time period when tape coatings were such
>>>> that reading them without "baking" them is very risky - this might be
>>>> before that era - Al Kossow would probably know - so I'd likely "bake"
>>>> it first before trying to read it.
>>>>
>>>> Given the name "IEBUPDTX" this tape was certainly intended to be used on
>>>> a 360 or 370, as you described below (IBM has a utility IEBUPDTE).
>>>>
>>>> So, if you haven't found somebody to read this thing yet, feel free to
>>>> contact me.
>>>>
>>>> JRJ
>>>>
>>>> On 8/2/2021 10:11 AM, James Liu via cctech wrote:
>>>>> Thanks for feedback and offers to assist.  I received the tape from
>>>>> one of the maintainers of Schoonship at CERN, and it was probably made
>>>>> around 1978 at SLAC.
>>>>>
>>>>> For some background, Tini Veltman developed Schoonship in the 1960's
>>>>> at CERN on the CDC 6600.  My understanding is that he more or less
>>>>> insisted on coding in assembly since he thought FORTRAN or other high
>>>>> level languages would just get in the way and slow things down.  The
>>>>> code was maintained by Veltman and Strubbe well into the 1970's, but
>>>>> its future was held back by being so closely tied to CDC hardware.
>>>>>
>>>>> In the mid 1970's, Strubbe began a conversion of Schoonschip to IBM
>>>>> S/360 and S/370.  It was sort of a curious technique, as far as I
>>>>> gathered.  The idea was to first translate CDC COMPASS source to an
>>>>> intermediate PL/I like language.  But then, instead of using the IBM
>>>>> PL/I compiler, a bunch of macros were developed to implement the PL/I
>>>>> like language in IBM assembly.  This conversion was never fully
>>>>> completed for reasons unknown to me.
>>>>>
>>>>> Later on, when Tini joined the University of Michigan (that's where
>>>>> I'm located), he realized that Schoonschip needed to be updated.  But
>>>>> the update was ... instead of CDC assembly he decided on m68k
>>>>> assembly.  (At this time, in the early 1980's, C probably would have
>>>>> been the natural language of choice.)  Moreover, he insisted on
>>>>> developing his own toolchain (assembler, linker, etc).  This was
>>>>> before my time at Michigan, but basically he ported Schoonschip to
>>>>> just about all the m68k machines of that era (Sun, Atari, Amiga, Mac,
>>>>> NeXT, and others I am not familiar with).  We have a pretty good
>>>>> collection of m68k code
>>>>> (
>>>>> http://www-personal.umich.edu/~williams/Vsys/index.html
>>>>> <http://www-personal.umich.edu/~williams/Vsys/index.html>
>>>>> ), but nothing
>>>>> earlier.
>>>>>
>>>>> Getting back to the tape, I'm pretty sure it has Strubbe's PL/I like
>>>>> code as it is an archive of the PL/I conversion.  It may also have CDC
>>>>> source, but that is less obvious until we can see the contents.  The
>>>>> CDC source is historically the most relevant, and I am hoping it
>>>>> exists on the tape.
>>>>>
>>>>> - jim
>>>>>
>