I didn't get much done tonight, but single stepping is a lot more stable now. I've updated the window update so that it doesn't request the current view every time you single step. This obviously won't work for self-modifying code, but for now it makes it much quicker to single step. I'm trying to get the RTS instruction to work but the register update doesn't appear to be working yet. The idea is to simulate RTS and RTI (and possibly JSR, JMP and all the branches) but this involves updating the registers to their new values.
I'll need to clean the monitor code up once its all working, as its getting a little messy just now. Also I'm still having trouble debugging this code as devstudio doesn't appear to want to load the symbols for all the modules its loaded....very annoying!