Now Playing

Tandy CoCo 3 512K RAM Expansion Upgrade

Published September 29, 2023

About This Video

Join me as I upgrade my Radio Shack TRS-80 Color Computer 3 from its stock 128K memory configuration to 512K of RAM using the TRIAD SRAM upgrade board from Cloud-9.

Released in 1986, the Tandy CoCo 3 added improved graphics and expanded memory capabilities to the TRS-80 Color Computer line while retaining the Motorola 6809E processor.

Upgrade Process:

  • Opening the CoCo 3 case
  • Removing the factory-installed memory chips
  • Installing the Cloud-9 TRIAD 512K SRAM board
  • Replacing the 128K badge with a 512K badge
  • Power-on testing after installation

Upgrade Benefits:

  • Expansion from 128K to 512K of RAM
  • Support for more advanced software
  • Improved expandability

Future Upgrades Discussed:

  • Motherboard recap
  • Hitachi 63B09E CPU upgrade

With the TRIAD board installed, my CoCo 3 now has four times its original memory and is ready for software that can take advantage of the additional RAM. I also replace the original 128K badge with a 512K badge to match the upgraded configuration.

For more information, check out my Tandy Color Computer 3 System Guide.

Watch on YouTube (external link)