DEC Professional 350: Booting

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I found the DEC Professional 350 in Ebay for just $150 and I considered a nice way to get a PDP-11 system that could at the very least run BSD— for a decent price. PDP-11s are not only expense but the peripherals are also expensive prone to issues and it’s difficult system to bootstrap let alone install an OS. So I got the system.

Then I learned that you have to have a monitor cable attached to past the POST testing. And you also needed a pretty obscure type of DEC monitor to run and use as the console. You can attach a terminal to it, but it’s not setup to use a serial terminal like a traditional Unix PDP-11. The Pro came with an OS call P/OS and was really a glorified Word Processor and Terminal itself- it was sold as an alternative to the IBM PCs (XT I suppose?) of the time (early 1980s).

Just about a month later with the help of some saved eBay Email Alerts I picked up a PRO-350 monitor at a decent price as well as a nice keyboard and proceeded to boot the system. Not only did it boot right up but it has the POS installed and working and a bunch of old Text files to boot. 

Next when I’m tired of the POS I have another HD to install and then attempt to install BSD on it, following the directions here at

As an aside, I also ended up purchasing a VT-100 terminal, which I used to have and regretted getting rid of. I also had to purchase a Windows box that could write 5 1/4 floppies. Getting this was difficult because I didn’t want to get a piece of junk from eBay that I would have to spend more time on. I managed to get a nice ‘refurbed’ Digital 486 that was nice because it came working with a ethernet card, CDROM and a fresh install of Win98 with drivers for the ethernet. With this I’m able to boot and connect to my local SMB NAS and grab the disk images for BSD that I’ve download off the Internet using a new system and browser. The Explorer in Win98 is extremely painful and often useless on the modern web of today.

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The Pro-305 Booting up. The HD works like a champ and doesn’t make any funny noises at all.


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The POS Main Menu. Not a lot of choices.


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The 486 Digital PC I picked up to make floppies.

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And this was a brand-new-in-the-box Digital PS2 keyboard that I couldn’t resist picking up. These are amazing to use and they have great key travel and feel- just a nice heavy PS2 keyboard for when you need one.


3 Month update:

I never managed to get the 5 1/4 floppy drive to work with the DEC 486. It may be broken as the BIOS seems to indicate there should be no issues with one. I never installed BSD and left the working POS on the drives. It’s an interesting system but nothing UNIX like at all and so it’s been put away to make room for the Amiga uplift.

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