3 Comments

https://archive.org/details/bitsavers_burroughsBryDumpSep79_5553606/mode/2up

https://www.jaapsch.net/mechcalc/burroughs_books.htm

https://www.picklesnet.com/burroughs/documents/Burroughs%20B80%20-%20A%20Bargain%20System.pdf

I can't find the instruction set. Not surprising, I doubt Burroughs really wanted to publish it. The B80/90 vanished without trace or descendants in 1981, when Cumbernauld was shut down.

Expand full comment

The Burroughs B-80 computer from 1978 was a silicon realization of a mechanical calculator, complete with 20-digit decimal accumulator. In Cumbernauld, Scotland they were still making the mechanical marvel on the main factory floor. When I arrived to work on the chip my desk contained a service manual for the calculator, which contained roughly 10,000 parts which unfolded in layers to allow service access. Just amazing, a bit like watchmaking scaled up to a 30 kg electric typewriter.

It was the most bizarre instruction set I ever worked on, it made a Z-80 look like a marvel of symmetry. Every register was special purpose, and if you could operate from A to B you could be sure the operation from B to A did not exist. It had a COBOL compiler and an OS, and was widely used for data entry systems in banks since it was (for the time) highly integrated into 2 chips and fit in a desk with the CPU about the size of the drawers you would have on one side. My work was to add transparent memory swapping so the DRAM could go beyond 64kB in the B-90, its successor. The rise of the PC wiped out that business, they closed the plant in 1981.

Expand full comment

Wow that sounded crazy, I got to read more about this computer. I did a quick Google but my initial results didn't give a good view of the things you describe here. Just showed it on the surface where it looked kind of normal.

Expand full comment