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 <cct...@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 <p...@teleport.com <mailto:p...@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
