Up to MUL now.
I found 2 bugs in the upd7810_table.cpp file while fixing cycle timings:
1. The first few prefix 40 opcodes are calling the 1-byte &upd7810_device::illegal handler instead of the 2-byte &upd7810_device::illegal2 handler, I don't know what sort of havoc this would cause since it only affects illegal opcodes. Because the opcodes have a prefix byte, they are 2 bytes long, so it should (if I'm understanding this right) call the illegal2 handler.
2. The more serious issue is a probable bug with the prefix 4D opcodes MOV_TXB_A, MOV_TM0_A, MOV_TM1_A, and MOV_ZCM_A which I'm pretty sure (based on the upd7810 instruction set databook) are in the wrong order in the table, causing the wrong opcodes to execute!
EDIT: scratch #2, the documentation conflicts with itself; I suspect the current order of things are correct since otherwise I suspect stuff would work much worse than it already does, if it has to do with serial communications and zero cross timing. Golden Child, correct me if I'm completely wrong here.

LN