Cool! :-)
HotCat, I'm not sure if you're aware or not, but the pins are not finalised yet. See this link for more details:
http://issues.freeems.org/view.php?id=190
I strongly recommend that you make allowances for jumpering between your drivers and the CPU such that pin functions can swap without affecting you. Particularly, make sure you can access PORTT 2 - 7 and PORTA and PORTB easily.
Excuse the off topic.
BTW, in lieu of the JimStim, you could put your own board together with an s12xdp512 and run freeems bench test code against your real freeems, just a thought. It's not coded to that level, yet, but it is codeded to work in a simple way! :-) It would be fully capable of complex patterns, probably unlike the function generator, and more accurate than the jimstim which is low on cpu power.
Fred.