Isn't the high level Burroughs assembly a compertly insane almost high level language? I looked into implementing it into my assembler and just ran in the other direction when I saw how much unnecessary co plexity there was in the language.
B90 was an 8 bit machine and was built at Cumbernauld in Scotland, where I worked. The B900 had similar architecture.
There was also a B1900 built in Liège in Belgium, which was a 24 bit machine whose instruction set was designed to run virtual machines (i.e. interpreters). Those systems had a reputation for being slow. I don't know much about them.
The Liège plant closed around 1982 and the Cumbernauld plant closed around 1985.
Burroughs mainframes (B5000 onwards to A series) may be the ones you're thinking of. These are justifiably praised for being ahead of their time. They were high level stack based machines with 48 bit words + 3 tag bits, and programmed directly in an Algol 60 variant, with additional instructions to enable COBOL to execute efficiently. There was no assembly language needed.