A thesis by Jian – Xiong Shao, 1983, titled OUP/M – A 6502 Operating system, contains a floppy disk based operating system for the 6502. It is modelled after CP/M and follows the same design principles.
In the development of OUP/M, an OSI C-3 microcomputer system was used. This system consists of a 6502 CPU, a dual 8-inch floppy disk drive, a console, a printer, and 56 K bytes of RAM.
On this machine all I/O is memory mapped and address space layout has to be taken into consideration.
For years only the document was available, archived on archive.org, with the source in the document.
Jian – Xiong Shao did not publish more 6502 code, further implementations are unknown.
A revival
In 2018, a thread on the osiweb.org forum appeared, user KIball, Charles Mangin, option8, typed in the sources and tested it on an emulated OSI C3.
The results are published on his github.
See also:
User wikokim on the forum.classic-computing.de bought this system in 1978/79. And published the following documents and ...
This page is about the operation and use of the Rockwell Single-Chip RSC-FORTH system as implemented in the Rockwell R65...
Rockwell made many 6502 variants. Some were 'SOCs', complete computers in an IC. and Rockwell was strong in Forth, e.g....
I have two R6501 IC's. One came with the Glitchworks GW-R65X1QSBC-1 kit, a R6501Q. The other from ebay, a R6501AQ (A for...