Reproducing old machines with newer technology (Re: PDP-12 at the RICM)

Jay Jaeger cube1 at
Wed Jul 15 19:56:02 CDT 2015

Saul is indeed cited in the ACM article,

I know that Purdue had some folks that did their own maintenance, and
sure, by the late 1960's one could certain pick them up cheap - the gold
scrappers were not quite the issue they became later.  I know this
because, besides the 7094 II that I did some work on (including
replacing a germanium transistor with a modern silicon one at one
point), the U. Wisconsin Chemistry department had a 7090 (oil core) on
the 9th floor.  Some folks from Purdue came up at one point and helped
fix a problem with it.

Around 1975 the IBM 1410 and the IBM 7094 II we played with at UW were
sold to a company in Ohio - or at least pieces were.  Paul Pierce and I
went back to that same company in 1998 and recovered some of the IBM
1410 and IBM 709x tapes that he lists on his site - Paul has an amazing
setup where he reads the tapes *analog* using a 7 track drive, and then
post-processes the results to de-skew and recover the data.


On 7/15/2015 7:12 PM, Chuck Guzis wrote:
> On 07/15/2015 04:05 PM, Jay Jaeger wrote:
>> Paul adapted PUFFT (Purdue University Fast FORTRAN Translator) to do
>> RS-232 bit serial I/O through a sense switch, and I wrote a spooling
>> program that ran on a Datacraft 6024 located in the same room to do the
>> card reading and printing.  I suppose somewhere inside of it the DC 6024
>> was humiliated - I expect that it was much faster than the 7094 II.  ;)
> I remember PUFFT--that was Saul Rosen's baby, wasn't it?  A FORTRAN for
> undergrads--put in anything that *resembled* a FORTRAN statement and get
> some sort of result.  Missing parentheses?  Misspelling?  Outright
> syntax errors? No problem.  I think Purdue had two 709x systems for
> PUFFT  The CDC 6500 was reserved for Serious Work.
> I understand that at the time, 7090/7094's were comparatively plentiful
> and (comparatively) inexpensive, hence their use.
>> Liquid nitrogen would be the "or worse" part.  ;)
> Neil had a lot of interesting stories about the ETA-10 (originally named
> the GF-10 for the target of 10 gigaflops).  It all seemed so fantastic
> back then.
> Ah, it's all fun...
> --Chuck

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