TMS9929A VDP Rediscovery and Alternative Retro VRAM Solution

The TMS9929A / TMS9928A / TMMS9918A are Video Display Processors produced by Texas Instruments in the Retro 8-bit era of the early 1980’s. They were used in a number of 80’s systems, including the ColecoVision, CreatiVision, SpectraVideo, MSX, and Texas Instrument’s own TI-99/4A Home Computer. Join me as I rediscover my own TMS9929A experience from the 80’s, and recreate a TMS9929A setup with the latest optimal video output, and design an improved alternative Video RAM solution. I walk-through my design process, then demonstrate the working solution with a walk-through of my Arduino sketch which fully tests the improved VRAM solution with multiple pass, multiple bit-pattern tests. My alternative VRAM solution comprises just 4 ICs (totaling just 70 pins), significantly less than the original 128 pins (8 ICs) or the 102 pins (5 ICs) of a 2010 published Static RAM solution. Next step will be implementing the successfully tested circuit onto a Minimalist Europe C