Smoke Signal Broadcasting produced a disk operating system called DOS-68 for the 6800 line, a set of add-on disk drives for it, and, later, direct competitors to it in the form of their own Chieftain line.
Technical Systems Consultants produced FLEX, an OS for the for the 69/A system, and later UniFLEX, a Unix-like OS for their S/09 machine. When IBM PC's were just beginning to become popular, and MS-DOS was still using a flat filesystem, TSC had (almost) Unix running on an (almost) 16-bit machine. (Flex was also ported to the Radio Shack Color Computer, and there is an emulator available for it from Black Belt Systems.)
Gimix also produced a line of SS-50 machines, about which I have almost no information. (Anyone care to fix that?)
Microware made OS-9, another Unix-y OS for the S/09, which was also ported to the Radio Shack Color Computer. This still has quite a following. (Links?)
I am very interested in tracing the legal status of SWTPC and SSB copyrights. Did they go bankrupt, get bought-out, just stop doing business, what? What became of their assets? Any leads would be welcomed, including names of former employees who might be willing to pass on more info, dates at which the company's legal status is known (ie: still in business or not), and so on.
If it turns out that those copyrights are somehow no longer effective, or if their current owners explicitly grant permission, I hope to post programs and documents. In the meantime, I have to assume those copyrights are in effect, and avoid copyright violations. (Oddly enough, that catalog that I scanned in doesn't have a single copyright notice anywhere!)
TSC's assets, legend has it, were bought out by other companies, ending up with RTMX here in NC. Search in Deja-News for "entire UniFLEX Source Code" to get the story, or see my locally-cached copy of it. There is a story about my search for this info.