An interesting finding by railsrust:


These Human-Machine-Interface chips control an LCD display, a touchscreen, and audio out, have on-chip RAM for display buffer, fonts, textures, had a QSPI MCU interface for control and another QSPI for optional flash storage.

And they are only $5.



The output to the LCD seems to follow video style standards for timing: two sync signals, three 8-bit colour channels. There is a clock output but it's optional, presumably because LCD panels resample according to strict standard timings. With three DACs, or by using only 1 bit for each of RGB, it mightn't be too hard to produce conventional video out, for SCART or VGA or similar.

Web page here:
https://brtchip.com/bt81x/

Datasheet:
https://brtchip.com/wp-content/uploads/ ... _BT81X.pdf

Application note for selecting an LCD display:
https://brtchip.com/wp-content/uploads/ ... isplay.pdf

It's a wonderful chip with a built-in ASCII font (among others). Pair it with this DAC and you've got VGA output (more or less).
https://www.mouser.com/ProductDetail/Analog-Devices/ADV7120KSTZ30?qs=sGAEpiMZZMv2b1PoHSP3neAsQKiGwBB4SDvllpgh4lc%3D

I will note that the latest Gameduino board uses this chip (BT815) and it is very powerful:

https://www.crowdsupply.com/excamera/ga ... 3x-dazzler

Has anyone created a 65C02 SBC in the Arduino shield format that this could potentially plug into?