An RGB mod for systems using TMS9928A and TMS9929A graphics

This small adapter board can unlock the potential of many 8-bit systems from the 1980's including the TI-99/4a, Colecovision, MSX, SG-1000, SC-3000, Memotech MTX, and more. Instead of the original output—often wavy, blurry RF with color fringing—soldering this tiny board directly to the back of your graphics chip will enable clean RGB output, ready to be sent to your favorite line doubler (like the OSSC), RGB monitor, or upscaler (like the Framemeister).

This solution is completely analog, introduces zero latency, works in NTSC or PAL systems, doesn't require any tuning, and can be installed easily. It outputs both buffered, video-level C-sync and 5V TTL-level C-sync so there are many options for interfacing with your favorite cables and output jacks.

TMS-RGB was developed in 2020 and solves all known issues found in previous TMS992xA mods of this kind.

The best place to get support is the official launch thread at AtariAge.