Homebrew 6809 Computer: Color Video! (TMS9918A)

Last weekend it was audio, this weekend it's video! I have the 6809 connected to a TMS9918A video chip.

The TMS9918A was used a number of early-'80s computers and consoles, like the ColecoVision, the TI-99/4a, and the MSX1. It's quite underpowered, and not as nice as the chips in the NES or Commodore 64, but there are plenty of them for sale on eBay.

Capabilities: 16 colors (actually, 15 plus transparent), 32 sprites, 32x24 tiles in graphics mode and 40x24 in text mode. No hardware scrolling, unfortunately.

This is a simple simulated "splash screen" that uses graphics mode II. The color cycling is achieved by changing the values in the Color Table during the vertical blanking interval.

Now it's time to write some freaking games!

Видео Homebrew 6809 Computer: Color Video! (TMS9918A) канала Matt Sarnoff