It would be a huge task. I am one of the co-authors of Nitros9 which was a complete rewrite of the original Microware version that took advantage of the Hitachi 6309 CPU with enhancements. Level 1 we have it running in 32k barely, not much room left for programs to run. Level 2 would be a little more difficult. Sure the expanded memory of Rex and such. But Level 2 had a unique Vector page in hardware that would keep 512 bytes of RAM at the top of memory no matter what memory is mapped into the workspace would have this constant 512 bytes always there. It is used to do the task switching and memory mapping for the numerous tasks you had running.
Now if anybody is interested the entire Nitros9 source code is available freely at: https://sourceforge.net/projects/nitros9 It's completely free to download and look at. There are many people working on it now, but at the beginning of the project back in the ‘90s it was just 3 of us that reverse engineered the code and re-wrote it. Bill Nobel b_nobel@ <mailto:[email protected]>hotmail.com > On May 1, 2016, at 1:03 AM, Hiraghm <[email protected]> wrote: > > I know awhile back folks were talking about a CP/M port for the Model T. > Earlier today I was watching some Youtube videos on CP/M, which reminded me > of OS/9, and that got me wondering. > OS9 is re-entrant and position independent, multi-user and multi-tasking. > The original OS9 was designed to operate in 64k of ram. > > I understand that the 8085 doesn't have relative addressing? I think that > could be worked around, however. Maybe. > But I was wondering if maybe a custom subset of OS9 could be developed for a > rom image, taking over the Model T, and be designed to work with the Rex, Rex > 2 and Quad add-ons? > An OS that could "flatten" the memory banks of the Quad would be fantastic, > and working with the Rex 2's built-in storage would, imo, make the Model T > much more useful & powerful. > > I don't know enough to know whether or not such a thing is feasible.
