Astute readers of the MAME release notes may have noticed multiple revisions of a game added to MAME 0.139 called "Quizard". Quizard is noteworthy for being one of the few arcade games to be based on the Philips CD-i game console, and benefits from my ongoing CD-i work in MESS.
Quizard consists of a standard CD-i console with a separate I/O board hooked up to both the front and rear serial ports, with a protected i8571 microcontroller in tow for copy protection. For anyone interested in seeing what the machine actually looks like, pop on over to Interactive Dreams and read the (short) article on the game: http://cdii.blogspot.com/2007/06/cd-i-arcade-conversions.html
The game currently fails to boot in MAME for unknown reasons which I am in the process of trying to track down. While it also fails to boot in CD-i Emulator, it does so for different reasons than it does in MESS - MESS seems to get stuck in an OS call shortly after the OS launches the cdi_quizard executable module, whereas CD-i Emulator loads it, tries to send data to the (non-existent) I/O board, then hangs while waiting for a response.
The first order of business is going to be to get MESS into a state where it will run as far as CD-i Emulator does. This shouldn't be overly difficult, as I've almost narrowed down specifically where it's crashing. After that, I'll need to verify that the UART handling in MESS's SCC68070 implementation is okay. Lastly, a lot of guesswork to try to figure out just what the heck it is that it's trying to send to the microcontroller will be necessary, but that should be reasonable considering that much more nefarious protection is broken in MAME with some regularity. After that, everything should be peachy.