The Omniboard is a Color Computer cartridge PCB that includes the circuitry needed to connect with a Teensy 3.5 or 3.6.

Below lists posts, code, and videos I’ve done with this device.

September 27 2020:

Video: https://youtu.be/RF1irLrpTtw
Source code: Blink

October 11, 2020:

Source code: Interrupt RAM