[TUHS] PDP-10 UNIX?

Johnny Billquist bqt at update.uu.se
Mon Sep 18 12:34:56 AEST 2017


On 2017-09-17 18:33, Arthur Krewat <krewat at kilonet.net> wrote:

> Was there ever a UNIX or even the thought of porting one to a PDP-10?

Definitely a thought. An attempt was started on NetBSD for the PDP-10, 
and it sortof got halfway of getting into single-user, but I'm not sure 
if the person who worked on it just got distracted, or if he hit 
problems that were really hard to solve. I certainly know the person, 
and can find out more if people really are interested.

> 36-bit machine, 18-bit addresses (more on KL10 and KS10), and:
> 
> *0 would return register 0 instead of a SIGSEGV ;)

Yes. Not the first machine that would be true for. You don't have 
address 0 unmapped on a PDP-11 either.

> 8-bit bytes would have been a wasteful exercise, but you never know.
> (losing 4 bits of every 36-bit word)

Uh... Why 8 bit bytes? That way lies madness. There exists a really good 
C compiler for TOPS-20 - KCC. It uses 9 bits per byte. Works like a 
charm, except when some people write portable code that is not so 
portable. ;-)

KCC was written by KLH, unless I remember wrong. Same guy who also wrote 
the KLH-10 emulator.

	Johnny

-- 
Johnny Billquist                  || "I'm on a bus
                                   ||  on a psychedelic trip
email: bqt at softjar.se             ||  Reading murder books
pdp is alive!                     ||  tryin' to stay hip" - B. Idol


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