Dr Who and Prime Computers

Two of my favorite things - Doctor Who and 80’s computers!


I re-posted something that was already posted, didn’t I? I hate getting old. :frowning:

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I’m not sure if you did - I can’t find a previous post. I’m fairly sure it was posted to G+ back in the day… ah yes, here. Here’s a bit of a paste (all links are archive links):

Stop press: bonus video All Tom Baker Doctor Who Prime Computer Ads
Here are some pictures and links (far far below) about Prime computers, including “What Happened to Prime Computer” and some photos from Vintage Computer Festival East 6.0 - prompted by +Jac Goudsmit’s excellent comment on a previous post:
“”“My school got rid of some Pr1me computers around the same time as I graduated from my BCBS study (1993). My friends and I knew the people in the school’s IT department well, and we knew about the discarding event before it happened. We helped them dismantle some of the hardware, and I ended up with a Pr1me 2350 computer, two 19” hard disks (300MB and weighing about 100lbs/56kg each), and a 9 track tape drive similar to the one in this movie.

Unfortunately mine didn’t have the transparent lid so you couldn’t really see how it worked (the lid had to be closed for the vacuum-based threading to work, obviously, but you could open the lid once the tape was threaded (I think you had to override the safety but there was a button combination to do that), and you could initiate a self-test from the front panel to make it go back and forth lots of times which was an amazing sight to see. The tape runs so fast through the drive that you keep wondering why it doesn’t get shredded or stretched out all the time, but the tape is much thicker than, say, consumer audio or video tape.

Booting that Pr1me 2350 from a Primos v23 tape took close to a half hour (the machine’s speed and abilities were similar to an 80386 computer at 16MHz or so but it was intended to be a multi-user multi-tasking system). It was fun to show it off, doing that. I also remember that I had to reconfigure the hard disks for staggered startup: if you’d start the spindles at the same time, it would blow the 16A/220V circuit breaker of the house. And I always loved when people said “WOW this thing is LOUD!” and I would say “Yes, and that’s just the fans running, I still have to spin up the hard disks”. Good times!

I tried to get a computer museum to take the machine from me when I emigrated, but they weren’t interested. The 2350 is supposed to run from built-in SCSI disk/tape drives and I didn’t have those, the SCSI controller had been broken and the SCSI tape drive and hard disk had been repurposed before I got the computer so it wasn’t complete. I couldn’t take it with me and I couldn’t store it (it’s the size of a big tower PC) so I had to take it to a recycler. Too bad because there’s very little information available about it nowadays. Pr1me Computer has all but been forgotten; CHM has one little Pr1me standing somewhere in a corner, you have to look for it to see it."""

A few photos in misc pages:

More on Prime’s history:

Prime info:

The featured link was:
The History Of “Prime Computer, Inc.”

Seen in the comments:

Matt Madison

Yes, there were several memory models: R-mode (real), V-mode (virtual), I-mode (indexed), and one more that I don’t remember now but was rarely used. Different instruction sets for the different modes, too, I believe, but fortunately I didn’t have to do much in assembler on them; a lot of the system-level code and utilities were written in subset of PL/1.

Ed S

I haven’t yet found a full technical story, but it seems the missing mode is S-mode for segmented.

Ed S

(Ah, Q 2.18 in the FAQ: http://www.malch.com/prime/primefaq.txt)

Matt Madison

Right, S-mode!

Stephen Gunnell

I used to program in 32R mode on a system that used PRIME 200 boards and later programmed and sys administrated on a number of small PRIME boxes. Then I shifted to Unix and had to relearn everything.

Ed S

I found a brochure on the PRIME 200:
(It’s FORTRAN all the way down - with added support for octal constants)