TODO: Compare A-Z80 core to current TV80

[rejunity]

Replace TV80 with A-Z80 core https://github.com/gdevic/A-Z80

Compare:

• die area
• support for illegal instructions

[omikron88]

A Z80 is based on die analysis of real Zilog Z80 CPU. I expect it will be more accurate, than re-implementation.
Other thing is die area.