At some point (many moons ago.. in a far distant galaxy far far away) I wrote a simple "flat" spinning square in STOS. I think it was just using sine/cosine to spin in a circle and I just plotted 45deg out and joined the points for the 4 edges of the square. So it would actually spin. Though that is as far as I got.
Actually coding a 3D cube is beyond me, so I wonder if anyone has any ideas how to code one in basic, It can use the VDI routines, which would probably be a advantage long term. I don't want to use lookup tables, it must calculate on the fly, Its a test routine I may ultimately add into Gembench