Dec's OS-like RSX-11M for the Z280 CPU | Hacker News Reader

Dec's OS-like RSX-11M for the Z280 CPU

github.com

36 pointsJPLeRouzic6 comments

Nice - the Z280 was an amazingly capable CPU which never gained much popularity.

There is also a Unix-like OS for Z280-based systems, Uzi280 based on Uzi for the Z80 by Doug Braun.

Uzi280 is a 7th Edition Unix clone with multiuser and multitasking functionality. It supports binaries with separate I&D (instruction and data spaces, similar to larger PDP11 systems), code sharing, process paging, and a hard-disk cache. The kernel is mostly written in c and fits into a single 64K memory segment.

A description of Uzi280 can be found at https://oldcomputers.dyndns.org/public/pub/rechner/zilog/z28...

However, the downloads linked there no longer work. You can find a copy of Uzi280 and other software for Z280-based systems at https://github.com/agn453/Z280RC and an emulator at https://github.com/mtdev79/z280emu

Update - we used to host Z280 at the Unix-AG ftp server in Siegen, which is no longer online.

I uploaded a copy of Uzi280 release 1.12 from a backup to https://multicores.org/uzi280/

Alan Cox has a "Fuzix" repo, that puts together Uzix variants for the Z80.

https://github.com/EtchedPixels/FUZIX

I see most of the comments are immediately cutting over to Unix clones, which is sad. RSX280 is a professional quality take of Dave Cutler's (yes, of NT fame) architectural innovations in RSX-11. The Unix groove is worn deep, deep into the vinyl. Expand your horizons! RSX280 is unlike Unix in any way, and this is a Good Thing.

RSX-11M was released in November 1974, at the same time as CP/M, itself influenced by DEC's TOPS-10 operating system.

The first version of the RSX-11M file system had a flat hierarchy (as CP/M), meaning it was not possible to have folders inside folders.

RSX-11M 2.0 was introduced in September 1975, it was multi-users. For CP/M it was in 1979.

=> In contrast, Data General RDOS (Real-time Disk Operating System) was a real-time, multi-user, hierarchical file system operating system released in 1970!

Many command names from RSX-11 and CP/M are the same as in RDOS.

I think you may be thinking of RSX-11M. Dan Brevik was the main architect for RSX-11.

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