PDP-11/45: Begin Again

Back in the mid/late '80s, when I was a student at CMU, a computer club member introduced me to the club's nearly forgotten hardware lab. It was still stuffed with remnants of the earlier time-sharing age, including two or three full-cabinet PDP-11 systems with names like "Banshee" and "Centaur". I thought these were the coolest -- CPUs you could see inside, and hack with a soldering iron and a wire wrap gun. Real front panels with lights and toggles, and machine language programming as a physical activity. For a kid fascinated with computers, it was great. You couldn't get closer to the metal; you could quite literally get your head inside these machines.

I began spending off hours in the lab, puttering with the '11s and getting to know them. Eventually, the club decided it was time to clean house and remove all of the older equipment. Most stuff was scheduled to be hauled away to the dump, but I was welcome to anything I wanted to haul away myself in advance. So I bothered some friends with a car, disassembled one of the '11/45s there ("Banshee" I believe) which seemed like the nicest thing, and hauled it off to my off-campus house. There it resided in the basement with many other oddments for some years.

Eventually, I ended up moving out to CA, and after some time the 11/45 CPU was disassembled and packed into moving boxes for the west coast as practically as possible, leaving all the bulkier parts behind.

After a couple of years in CA, I happened on a decommissioned two-rack 11/40 system at Stanford, essentially free for the effort of hauling. This had most of the missing cabinetry, power supplies, and peripherals needed to reconstruct the 11/45! So I procured this and added it to a growing west coast equipment stash. And then real-life set in -- job changes, house moves, raising a kid... Through all of that I held on to all the parts, vowing to "get to it someday". I would pick through the stuff from time to time over the years, but never had the time to take the project very far.

Well, now "someday" is here! The kid is off to college and I've moved house once again, but this time I reserved some working space for the project and pulled all the parts so they are together and accessible. So here we go...

Here are some pics from the first weekend: the two H960 racks that are the bones of the whole thing, some glamor shots of the processor backplane and the RK11-C disk controller, and my buddy Chris helping to remount the RK05 drives on their rails temporarily to keep them off the floor and out of harm's way: