Done a bit more today, finished off the printing and menu options in the Executive part of the ROM. It's a bit like the old home computers, the ROM provides a set of utility functions and also some code using them - in this case, the game itself.
I have uploaded the unfinished ROM assembler code if anyone is interested - it's on the links on the right.
It can all be made to work - download the CP1610 interpreter, assemble that with AS1600, download the exec ROM assembler, assemble that with urmasm.jar, concatenate the two binary files together, call that file code.bin then run it with gimini.jar. If you do this you get a rotating menu of the type used in Unisonic games (the options change sequentially and you push 'Yes' when you see the one you want).
I will make a more releasable one when there is something to see.
Anyway, I will review this ROM code and then once that is done, start work on the Blackjack / Baccarat game.