If you want to do debugging in MESS, here are some tips.
Start MESS with the option -debug. This will lauch a debugger window. The most important things to know are:
- F5: Run
- F11: Single step
There is a command line at the bottom right. Interesting commands are those for handling breakpoints.
- bpset <hexaddr>
- bpclear <bpnumber>
When the execution reaches a breakpoint, it stops right there, after executing the line. You see the current workspace on the left.
You can open a memory dump window using the window menu or Ctrl-M. Note that earlier MESS versions had the issue that reading of GROMs or VDP was not blocked, so when you scrolled over these addresses, the emulated system would crash or react in some unforeseeable way. I fixed that in the latest release (0.149).