z80 timing... 6502 timing

What might speed this along is if we create a list of agreeable items, instead of speculating in space. As I have been reading the messages a list is forming for me. Some things in this contest that sound reasonable to me; Input and output are to memory resident buffers. Inline code is too boring, and subrountine calling too important, so the "task" should require perhaps modules; maybe make the contest half a dozen subroutines which get called from a contest defined main program (using some typical non asm language like C or pascal). Needs to be fun, NOT work, and should provide a good excuse to play with our old hardware. Contest submissions could be a simple binary file, file length, predefined jump table for subroutines, the actual code. Some third party, can run the code and time it on the hardware of their choice.