With only a month from the announcement of the HaD Prize 2023 to the close of the first challenge round there certainly isn't a lot of time to come up with something brilliant - but challenge most certainly accepted!
It certainly doesn't leave a lot of time to source parts for the prototype but thankfully I do have a left over 6507, a couple of 6532's and some ROM's - hopefully I will get the PCB in time to try it out... and if I know my luck, time to make some bodges before the challenge round is over.
I started thinking about the project on Sunday and I'm happy to say I just published the KiCAD files to Github. https://github.com/AndersBNielsen/65uino
If you see something weird I'd certainly like heads up! Planning to order PCB's tonight or tomorrow. (Note to self: Add pads for extra decoupling caps before ordering!)