Regular XaviX again so fits well with what is being worked on
I've been making good progress with these, found the test mode code in Monster Truck which has made the ram regions clear, as well as a number of registers.
Video hardware seems to be 256 sprites of varying sizes
Sound hardware is PCM sample playback
There is also a nice little multiplication chip there which the games make use of and the test mode code explicitly checks, which makes it clear what it is.
Fingers crossed I'll have something to show for this work over the coming days
One slightly strange thing is that this boxing rom is full of strings for the fishing game, I guess they reused the base code and didn't bother to remove them. (but it probably also means that Boxing and Bass Fishing were the same developers, who are named in the ROM)