> These two work fine in MAMECE-10X (Pacman even with sound). I don't know why
> they wouldn't be working in Mameboy.

The great Marconelly sent me working roms in the meantime.
:-)
You need "pacmanm" (Pacman Midway) for Pacman and the Roms for Burgertime and Frogger are also slightly different from the Versions used in DOS-Mame 0.36/0.37b14

> hardware, Atari System 1) isn't really easy since it also handles detecting a
> coin being inserted.

I heard about it. :-(
On the other hand, Marble Madness from the commercial Midway-Compilation for Windows (released 1998) uses samples and runs perfect on a P133. The game seems to be true emulation.

Greetings
Bern