A random work-in-progress MAME video: The "Mono-II" board variant of Philips CD-i compatible players. No audio, and it hangs when trying to open the disc tray, but notably, it actually emulates the two I/O microcontrollers rather than simulating them.https://www.youtube.com/watch?v=fTi-IwjMPGQ …
Actually running the code that the MCUs ran under an emulation framework for a Motorola MC68HC05C8, as opposed to kind of crappy code that doesn't entirely replicate the functionality.