> > Speaking of the Z80, would it be possible to run NuttX in a Grant Searle > / RC2014 platform with a 8k ROM /56k RAM split, or would any attempt > require banked memory? >
I don't know if it is possible or not. I don't know if NuttX is viable on any CPU limited to a 64Kb address space. In their day, those 8-bit CPUs were programmed in highly tuned assembly language. it is hard to imagine running an OS that is almost as big as the addressable memory and being able to do anything meaningful. NuttX may have outgrown these platforms. I think that z80 architecture support is still important because there are so many derivatives from z80, like that FPGA in the ZX Spectrum Next ( https://en.wikipedia.org/wiki/ZX_Spectrum_Next). That FPGA runs the z80 with a extended address space using an MMU similar to the z180 but with smaller pages. Other derivatives like the z300 and the ez80 just support a wider address space. I have done a couple of ezo ports recently (like http://z20x.computer/). I appreciate this discussion about protecting the NuttX supported platforms. > > So many RTOS are just for arm. > Originally, NuttX was focused on the hobbyist, DIYer, and retro-computing enthusiast. But nowadays, it is dominated by businesses with business value systems that are sometimes not compatible with the needs or interests of hobbyists. That is why there is such a long discussion in the INVIOLABLE.md under "All Users Matter." That was essentially the contract I made when I agreed to give the OS to the community. But it is going to take some strong leadership to keep those values since the OS is controlled completely by businesses now and businesses tend to think only of their own needs.