Would a set of basicly blockland versions of simple real world electronics such as transistors, logic gates, 7-segment display/bcd decoder be a good app?
Im also looking into ways to minimise my memory cells so that I can fit the memory for a reasonably sized screen with a 4 bit depth and fit in in a useful ish space(currently think i may be able to fit the entire optimised contraption in two 8x cubes)