More pro for the DEC Professional 380 (featuring PRO/VENIX)
9 comments
·March 16, 2025zabzonk
classichasclass
(author) Thank you! Was it because the cards fit badly on the CTI card edges or something else? These cards seem to be in pretty good. Doesn't look like Caltech did much with this one either. I need to get the other out and image its disk too.
zabzonk
We never identified the root cause of the problem. As we couldn't really do anything very useful with them, there was not much incentive.
zdw
The ascii art partway through the article is extremely endearing:
% cat /thankyou
THANK YOU FOR RESCUING ME
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******dboreham
A testament to the lack of success of this machine is that as a 50 year pdp-11 aficionado with a collection of machines from this period, I'd never heard of it until now! I knew about the Rainbow of course, and the pdp-8 based desk machines, but no clue this thing existed.
flyinghamster
In an alternate universe, DEC could have owned personal computing outright and caught IBM flat-footed. But they were deathly afraid of cannibalizing their minicomputer business, so the only home -11s that made it out the door without being hobbled were the Heathkits (H11 and H11A), and even those were sort-of hobbled in that they could only use 16-bit Q-bus cards unless you were willing to do some hardware hacking, even to the point of cutting a hole in the case. Otherwise, they were legit Q-bus LSI-11s that could run standard DEC operating systems, and V7 Unix as well (but not 2BSD due to memory constraints).
If you want to play around with an emulated Pro/350, there's an emulator and images here: https://xhomer.isani.org/xhomer/xhomer.html
There are images for P/OS, Venix, 2.9BSD, and RT-11 5.3.
rasz
> We simply can't seem to beat the Pro's firmware to come up first before the Pro concludes no hard disk is present.
>charge the capacitors (very fast) and start bringing up the BBG while the Pro's initial boot fails. With our new shortened boot time the BBG will be ready and waiting by the time the Pro displays its error screen. We then power the Pro off and power it back on. As long as the power cycle is less than 20 seconds (I eventually upped this to 30 as there appears to be plenty of power available), the BBG will ride the stored charge and keep serving the emulated disk image so that on that second power-on (and every power-on thereafter) the Pro will see the drive and boot from it.
eeew. Next time you are faced with such problem make your slow booting disk emulator control Reset signal of the main computer. Keep it in reset until emulator is ready.
bediger4000
This is an enormous article, filled with everything - DEC history, ads from period IT mags, pictures of fabled hardware, reminiscing, hardware restoration.
Locutus_
Great read, but I honestly had wished the author had split it into several separate articles.
When I worked at Middlesex Polytechnic in North London, UK in the mid 1980s DEC actually gifted us with three of these things (we were a big DEC customer - Dec10 and several VAXen). We really had no idea what to do with them as they came with no useful software - as I remember only the OS (RTX of some sort, I think) and a rather good Lunar Lander game. They were also terribly unreliable - the internal bus was very flaky. We accidentally fixed this by carrying them in the back of a van between Poly sites - the vibration re-seated things, and later worked out that lifting them a few inches and then dropping them did the same.
I also had a DEC Rainbow, which made a very nice VT200 terminal, but was otherwise nearly as useless. I did actually write some software for it to support the Polys student application clearing service, which made use of an 8mb hard drive that came packed in a crate about as large as a dishwasher.
I was so happy when the first IBM XT arrived.
PS Good article!