I think the only thing I would do differently would be a 'dark theme' case option as I find the yellow on white lettering to be nearly impossible to see (older

I think the only thing I would do differently would be a 'dark theme' case option as I find the yellow on white lettering to be nearly impossible to see (older eyes I guess). In the category of "all different", my all time favorite calculator is the TI-92+ which was a landscape style calculator with a qwerty keyboard. Building something like that with the 5" 800 x 480 IPS screen that STM has on the STM32F469i-Disco board would be heaven. It is on my long list of things which I will likely not get around to before I die :-). You could swap the STM32F769 for the 'F469 if you wanted more mips. I'd pay $300 for one of those, if you're wondering.