[TUHS] Teletypes used for early Unix

[Serge Burjak]

Hi Team,

First time contributor, long time reader.

I am a different Serge to the one in this thread.

Been active in computing in AUS  since the early 70s. Used Teletype KSR/ASR
33 from about 1973 to 1981. Many other CRTS, terminals as well.

These are my recollections. They may be flawed.

KSR 33 did NOT have a paper tape reader/punch. The Paper Tape punch and
reader were on the ASR33 model exclusively. These devices were mechanical,
ran at 110 Baud serial, typically in a 20 ma current loop for signalling.
Used ASCII. I do not know of any way to change the interface speed, only
ever saw 110. I have seen in magazines of the time, built in modems, but
none seem to have made it to Australia. The paper was typically a friction
fed via a platen. The interlock to stop multiple keys was done
mechanically. Fairly noisy. Wiki is not bad,
https://en.wikipedia.org/wiki/Teletype_Model_33

ASR/KSR 33 was a standard for all terminals in that era that used serial
ASCII.

The paper tape reader was used to bootstrap the OS to most minicomputers of
the era. There was a limit as to how much paper tape could be fed by the
internal feed mechanism and would often fail with a CRC check for larger
punched tape rolls. The reader and punch could be controlled by a key
sequence sent from the computer. Tape also ran at 110 Baud.

Used a cross section of mini computers, most DEC devices, right through to
PDP10 timesharing. DECWriters were very versatile and reliable across a
broad range of devices, more CRTS, and computers than I can remember.

Not sure if it helps.

On Wed, 30 Jul 2025 at 13:29, Jonathan Gray <jsg at jsg.id.au> wrote:

> On Wed, Jul 30, 2025 at 02:16:13AM +1000, sjenkin at canb.auug.org.au wrote:
> > Explaining John’s comment.
> >
> > I requested some reports from UNSW Archives in 2021.
> > This one, by Keith Titmus in 2000, was a short history of Prof Murray
> Allen,
> > who'd hired John Lions and Ken Robinson in 1972.
> >
> >       08_224_01 MW Allen_Keith-Titmus_2000
> >
> > There were some Decwriters at UNSW, but mainly ’Serge’ Terminals in 1978.
> > Designed and built by the local staff (Serge P).
>
> Before that, there was the INTERGRAPHIC, used with an IBM 360/50.
> Malcolm Macaulay
> A low cost computer graphic terminal
> https://dl.acm.org/doi/10.1145/1476589.1476688
>
> "INTERGRAPHIC system built at the UNSW between 1964 and 1966 by
> G. A. Rose under M. W. Allen. The design team included P. D. Jones,
> T. Pearcey, R. B. Stanton and M. Macaulay"
> https://www.austehc.unimelb.edu.au/tia/595.html
>
> Pearcey of CSIR Mk1/CSIRAC fame.
>
> An oral history of Murray Allen goes into Unix and Intergraphic.
>
> Murray Allen interviewed by David Demant in the History of ICT in
> Australia oral history project
> https://trove.nla.gov.au/work/178430368
>
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