I've been working on a Game Library for a set of computers made by VTech. I wonder if the MP Arcade Game Maker could be coded to work with these platforms? They are Z80.
I don't see why not. If you or someone else wants to take a look at the Spectrum engine and compiler, (the source for which is included in the download), I'd be happy to put some Windows editors together and output the data in a form your compiler would need. Essentially it would be a case of making a few changes to the compiler (CompilerZX.c) and engine (EngineZX.asm), modding the input and output routines to work with the VTech. So long as you are happy to write the code to write blocks and characters to the screen, move sprites, read the keyboard etc. it should be straightforward enough. The only other thing you might want to consider is making some parts of the engine conditional in order to save memory.
I'm happy to do work on it. There are some weird caveats with this platform so I'm not sure it'll be doable. No sprites and no Collison registers, for example.
I've documented some of it here: https://jasonoakley.com/foxglovz-dev/foxglovz-dev-diary-part-1/
Oh! On the Facebook group Kees says "The CCE-MC1000 has a Z80 and a 6847 so I think this is a good start."
There are no hardware sprites on the Spectrum either, the engine XORs sprites and objects on to the screen, then XORs them again to remove them. It does the same for the PLOT command so you might need to re-think these routines. All collisions are coordinate based so it should just be a case of modding the collision routines to work with half the resolution. Spectrum sprites are moved 2 pixels at a time horizontally so there are 4 pre-shifted copies of each frame on that format, you'd have to figure out what would work best for VTech. Objects aren't animated so those are shifted into position at run-time on the Spectrum.
The speaker looks very familiar so no worries there. :)