Why CP/M?
When CP/M has perioidically come up in the Facebook group, there is an argument about WHETHER one should be interested in CP/M on the CX16. That's the kind of argument I have no interest in engaging with. Do if you want to, don't if you don't want to, people who do want to "explaining" to people who don't why "they are wrong" or people who don't want to "explaining" to people why "they are wrong" is not a conversation I have the slightest interest in. I have been talking on the internet for nearly 40 years now (since before html had pictures), and I have seen hundreds of versions of the same conversation without yet seeing a point to it.
However, there is the other version of the question, which is curiosity. "But why are YOU interested in CP/M?"
Some may be interested in CP/M primarily for nostalgia. They used CP/M heavily "back in the day" and it doesn't really feel "retro" to them without a bit of PIP and SAVE action.
Now, I have some nostalgia for my little CP/M tablet, the Epson Geneva, with it's cute little built in answering-machine-tape drive and the micro printer I used to write letters home when I was in Grenada in the peace corps. But that is more nostalgia for the Geneva than nostalgia for CP/M ... I spent very little time IN the OS, and most of my time in Wordstar. A Wordstar-alike word processor is about as far as a CX16 system could go toward hitting that nostalgia unless someone made LCD tablet style case (with flip up LCD) for a CX16e board.
Rather, what I would find fun about CP/M are all of the retro programming languages it supports "out of the box", which no porting required (though sometimes with some tinkering with the terminal settings).
Consider Hjalfi's little demo of his Amstrad NC200 running CP/M off the 3.5" floppy disk:
https://youtu.be/FGWshrMZcCc With a good CP/M 2.2 with a reasonable sized Transient Program Area, you get multiple interpreted and multiple compiled Basics, m-code, p-code and native Pascals, Small C, BDS-C, Mix-C, fig Forth, DX Forth, Camel Forth (among others), Cowgol, J (APL for ASCII keyboards), Fortran, Cobol ... the list literally goes on. You might not have C++ or TCL or Perl or Python or Lua, but you have a whole bucketload of 8-bit era languages that could be hosted in a disk-oriented 8bit 64K address space system.
So if that kind of playground for old 8bit era languages sounds like fun to you, you can empathize with why I find the idea of CP/M interesting even though I am not particularly excited by the idea of doing a whole bunch of Z80 assembly language programming.
And if not ... well, I am not saying that the majority of audience for the CX16 "ought" to be interested in it. Just like those who are interested in the CX16 for whatever reason and would ALSO have a nostalgia itch scratched by a CP/M extension is a niche within a niche ... a subniche ... this interest area is ALSO a subniche, and that's fine with me.
This is why if a good cheap CP/M 2.2 expansion card is developed, I am not going to much worry about which approach it takes, I'll just buy it and stop scribbling down design notes for a dirt-cheap CP/M internal userport board.