I have ported MAME's M6809 core to FBA - this is used by many games so it should get some use and open the possibility for other drivers.
Thus far, I have a driver working (see screenshots below) but this is interfacing directly with the core. Now I know it works I need to complete the following tasks;
1. Create an interface to the core to be used by FBA drivers (similar to Sek, Zet)
2. Add support for the new interface to the BurnTimer module.
3. Add support for multiple chips to the new interface.
4. Add support for the new interface to the cheat engine.
Number 2 is fairly important as the chip is quite often used to drive sound chips. I will probably port Renegade when doing this as it uses a YM3526 which will require timer support and it is a classic game!
For number 3 there are plenty of options and I haven't made my mind up which game to test it with yet.
This is one CPU core out of three on our way to Double Dragon - although when support for multiple M6809s is added there is the possibility of adding the bootleg of Double Dragon that runs on three M6809s.