MICROCONTROLLERS

Ah, found the document I was thinking about earlier. Pacific Displays is a good tutorial on the basics, but it was... this guide from Microchip (https://ww1.microchip.com/downloads/en/appnotes/01428a.pdf) that intrigued me.

The waveforms that you need for a high-multiplex / high-bias LCD screen manually is rather complex.

These square-waves are created with the appropriate resistors hooked up between pins and synchronized to pass current to the different capacitors that have been connected in series (ie: each LCD "pixel" or "segment" is a series-capacitor).