hypothetical: more return stack levels on 11C, 15C, 16C

[brouhaha]

Hi David,

Thanks for the suggestions! Dot-matrix display is on my TODO list for real hardware that has such a display. I hadn't thought too much about doing that in Nonpareil II, but clearly if I can do it on some real hardware, I need to do it in simulation as well.

Currently Nonpareil II only has infrastructure for segmented displays, but supporting dot matrix is on the horizon, especially if I add support for the Saturn-based calculators that have such. Once the infrastructure is in place, there's no reason I can't use it for enhanced Voyager models as well.

Best regards,
Eric