3 Mar
2026
3 Mar
'26
1:40 p.m.
As a student at UC Berkeley (1967-1971), I had a part-time job at the Computer Center,
which ran a CDC 6400 under SCOPE. We punched cards, transferred them to magnetic tape, and
used UPDATE to maintain logical decks. I personally used this technology while working on
CAL SNOBOL and CAL TSS. Once we got CAL TSS far enough along to support development (on a
second CDC 6400), we switched to Teletypes (a mixture of Model 33’s and Model 35’s). I
still have source code for CAL SNOBOL because of archivists at U. of Arizona and U. of
Texas, but most of the source code for CAL TSS was lost (listings survive).
Paul McJones
https://www.mcjones.org/CAL_SNOBOL/
https://caltss.computerhistory.org/
3 Mar
3 Mar
3:29 p.m.
New subject: Operating system, on punch cards?
On Mar 3, 2026, at 5:40 PM, Paul McJones via cctalk
<cctalk(a)classiccmp.org> wrote:
As a student at UC Berkeley (1967-1971), I had a part-time job at the Computer Center,
which ran a CDC 6400 under SCOPE. We punched cards, transferred them to magnetic tape, and
used UPDATE to maintain logical decks. I personally used this technology while working on
CAL SNOBOL and CAL TSS. Once we got CAL TSS far enough along to support development (on a
second CDC 6400), we switched to Teletypes (a mixture of Model 33’s and Model 35’s). I
still have source code for CAL SNOBOL because of archivists at U. of Arizona and U. of
Texas, but most of the source code for CAL TSS was lost (listings survive).
It would be neat to OCR, or if desperate retype, those listings and bring CAL TSS back to
life.
paul
4:03 p.m.
New subject: Operating system, on punch cards?
On Mar 3, 2026, at 4:29 PM, Paul Koning
<paulkoning(a)comcast.net> wrote:
A fellow named Terry Heidelberg did an amazing job with a handful of surviving tapes.
Through heroic measures (I think he typed in programs from the listings, and patched
things like crazy) he got the ECS System (essentially the microkernel) booting and running
an interim command processor (the BEAD), but couldn’t get much past that (disk files and
the whole “user system” ran on that layer). So no subsystems could be run, etc. I recently
found a TTY printout of a session from around 1970 where I was demoing the system to my
wife by running a haiku-generating program written in CAL SNOBOL by Jim Gray. I’ve thought
about writing a blog entry annotating it: manual ECS quota maintenance, errors, restarts,
broadcast message by Dave trying to get Bruce to release ECS so Dave could do a big
assembly or link-edit.
Paul
On Mar 3, 2026, at 5:40 PM, Paul McJones via
cctalk <cctalk(a)classiccmp.org> wrote:
As a student at UC Berkeley (1967-1971), I had a part-time job at the Computer Center,
which ran a CDC 6400 under SCOPE. We punched cards, transferred them to magnetic tape, and
used UPDATE to maintain logical decks. I personally used this technology while working on
CAL SNOBOL and CAL TSS. Once we got CAL TSS far enough along to support development (on a
second CDC 6400), we switched to Teletypes (a mixture of Model 33’s and Model 35’s). I
still have source code for CAL SNOBOL because of archivists at U. of Arizona and U. of
Texas, but most of the source code for CAL TSS was lost (listings survive).
It would be neat to OCR, or if desperate retype, those listings and bring CAL TSS back to
life.
paul 
4:19 p.m.
New subject: Operating system, on punch cards?
Fantastic, thanks for sharing that Paul !
I see "SOS" (SHARE OS) from 1959 and expected it was a similar workflow:
initially on punched cards, intermediate fixes done on tape, then back to
cards-- for a brief time, wouldn't tapes be a form of your storage space?
so as you were "done" with the system - or a program completed and moved to
the next batch-sequence - someone else could re-use the tape? (I recall
earlier OS's, maybe CTSS, being like that -- if you logged out without
saving your workspace, you'd lose it ) Then c. 1962ish, SOS morphed into
IBM IBSYS. By that point, maybe nearly all the interactive development was
done on 7 or 9-track? ( was there an 8-track? I think Univac had an
8-track at same point? )
I have seen the 1401 demo at CHM, so this helps put it more into
perspective.
-Steve
On Tue, Mar 3, 2026 at 4:47 PM Paul McJones via cctalk <
cctalk(a)classiccmp.org> wrote:
As a student at UC Berkeley (1967-1971), I had a
part-time job at the
Computer Center, which ran a CDC 6400 under SCOPE. We punched cards,
transferred them to magnetic tape, and used UPDATE to maintain logical
decks. I personally used this technology while working on CAL SNOBOL and
CAL TSS. Once we got CAL TSS far enough along to support development (on a
second CDC 6400), we switched to Teletypes (a mixture of Model 33’s and
Model 35’s). I still have source code for CAL SNOBOL because of archivists
at U. of Arizona and U. of Texas, but most of the source code for CAL TSS
was lost (listings survive).
Paul McJones
https://www.mcjones.org/CAL_SNOBOL/
https://caltss.computerhistory.org/
4:27 p.m.
New subject: Operating system, on punch cards?
Steve,
Tapes were definitely expensive enough to be reused, but for something as important as
system software source code, people tended to keep them and rotate through backup tapes.
7- and 9-track tapes each had a parity bit and 6 or 8 bits of data. I believe they
attempted to distribute the original Fortran compiler (1957) as a deck of “binary” punched
cards, but had trouble with the card punches and duplicating equipment handling so many
holes.
On Mar 3, 2026, at 5:19 PM, Steve Lewis
<lewissa78(a)gmail.com> wrote:
Fantastic, thanks for sharing that Paul !
I see "SOS" (SHARE OS) from 1959 and expected it was a similar workflow:
initially on punched cards, intermediate fixes done on tape, then back to cards-- for a
brief time, wouldn't tapes be a form of your storage space? so as you were
"done" with the system - or a program completed and moved to the next
batch-sequence - someone else could re-use the tape? (I recall earlier OS's, maybe
CTSS, being like that -- if you logged out without saving your workspace, you'd lose
it ) Then c. 1962ish, SOS morphed into IBM IBSYS. By that point, maybe nearly all the
interactive development was done on 7 or 9-track? ( was there an 8-track? I think
Univac had an 8-track at same point? )
I have seen the 1401 demo at CHM, so this helps put it more into perspective.
-Steve
On Tue, Mar 3, 2026 at 4:47 PM Paul McJones via cctalk <cctalk(a)classiccmp.org
<mailto:cctalk@classiccmp.org>> wrote:
> As a student at UC Berkeley (1967-1971), I had a part-time job at the Computer
Center, which ran a CDC 6400 under SCOPE. We punched cards, transferred them to magnetic
tape, and used UPDATE to maintain logical decks. I personally used this technology while
working on CAL SNOBOL and CAL TSS. Once we got CAL TSS far enough along to support
development (on a second CDC 6400), we switched to Teletypes (a mixture of Model 33’s and
Model 35’s). I still have source code for CAL SNOBOL because of archivists at U. of
Arizona and U. of Texas, but most of the source code for CAL TSS was lost (listings
survive).
>
>
> Paul McJones
>
> https://www.mcjones.org/CAL_SNOBOL/
> https://caltss.computerhistory.org/
152
days inactive
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days old
4 comments
3 participants
participants (3)
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Paul Koning -
Paul McJones -
Steve Lewis