Oh, cool! Thanks for that link, the STM32F4 is pretty close to the F0/L0/L4 series that I've been learning about; I was actually thinking of using an L082KZ to start with because it has a lot of Flash, built-in EEPROM, a simple M0+ core, and is easy to hand-solder.

Cool idea using VGA as the output; was that hard, or could you just use the DACs normally? I was looking into parallel LCD interfaces for awhile - some F4 cores have a 24-bit RGB LCD peripheral - but they look complicated and I'm still puttering around with SPI OLED/TFT displays.

Anyways, looks like a really cool project!