From mboxrd@z Thu Jan 1 00:00:00 1970 From: bqt@update.uu.se (Johnny Billquist) Date: Mon, 18 Sep 2017 04:34:56 +0200 Subject: [TUHS] PDP-10 UNIX? In-Reply-To: References: Message-ID: <9e3b00fa-3688-73d1-b79c-b88c3bd99bdb@update.uu.se> On 2017-09-17 18:33, Arthur Krewat 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