I cleaned it up, but haven't ever transcribed ROM bits from a NEC micro before. Reading the datasheets, D557 sounds like a D553 without all the pins bonded out. I had picked up a Bambino Superstar Football in a bulk buy; it has a D553 that Kevin has dumped, so I decapped it. The die is extremely similar to the D557, and the ROM decoding is identical. I figured out how to map the bits to match Kevin's electronic dump, and did the same to Fabulous Fred. I ran the resulting file through unidasm and it looks OK to me, but I'm not familiar with ucom4. Interestingly, the last 48 bytes of Football and Fred are identical, and the datasheet goes to great lengths to say that the chips only have 2000 bytes of ROM (instead of 2^11=2048). So I'm guessing the last 48 bytes are reserved, probably for the test pin functionality. I'll document the hardware and upload everything.

I also got an Entex Space Battle with TMS1000:

And an LJN 255 Computer Command Datsun with COP4:

And an Incredible Brain Buggy is on the way.