[TUHS] Graphic Systems C/A/T phototypesetter

Brian S Walden tuhs at cuzuco.com
Wed Dec 11 03:32:35 AEST 2013

the one at WH was directly connected to a vax 11/780, no paper tape either.
so that now finally explains why /dev/cat was write only, it was substituted
for a paper tape reader. it was always a curiosity that you could write
to it, yet never read it (i.e. get a status). a "cat /dev/cat" would
get you a "cat: cannot open /dev/cat" while a "cat /some/file > /dev/cat"
would succeed, but act like you used /dev/null instead 
(as /some/file was not valid phototypeseter input)

> From: Doug McIlroy
> >  The wikipedia description
> >  <http://en.wikipedia.org/wiki/CAT_(phototypesetter)>
> > seems pretty accurate although I have never seen the beast myself.
> I can confirm the wikipedia description. At Bell Labs, however, we
> did not use paper tape input. As soon as the machine arrived, Joe
> Ossanna bypassed the tape reader so the C/A/T could be driven
> directly from the PDP-11. The manufacturer was astonished.
> The only operational difficulty we had was with the separate
> developer. If you didn't hand feed the end of the paper perfectly
> straight into that machine, the paper would tear. Joe Condon
> fixed that by arranging for the canister to sit on rollers so
> it could give when the paper pulled sideways.
> The first technical paper that came off the C/A/T drew a query
> from the journal editor, who'd never seen a phototypeset
> manuscript before: had it been published elsewhere?
> Doug

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