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Looking for CoCo help? If you are trying to do something with your old Color Computer, read this quick reference. Want to contribute to this wiki? Be sure to read this first. This CoCo wiki project was started on October 29, 2004. --OS-9 Al

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Home / Hardware - GIME



Year 1986
About the Hardware Info Box

GIME is/was a custom ASIC chip used in the Color Computer 3. It was designed by VLSI.


The GIME was designed by VLSI. Images of the GIME circuitry reveal the names J. L. Bruister (VLSI) and J. M. Prickett (Tandy). The book CoCo: The Colorful History of Tandy’s Underdog Computer provides some details on the design of the chip (starting at page 109 in the 1st edition printing).

Known Versions

  • PCB Prototypes - Implemented in discreet logic on the large PCB prototype units. Microware was known to have had at least two of these units, which today are in the collection of User:AllenHuffman.
  • Pre-Production - Launch-title developers received early production run CoCo 3s that had pre-production GIME chips. At least two variations are known to exist. We need to catalog and document them here.
  • 1986 - Code named "Tequila". This was the original production GIME. It contained some bugs that were fixed in a second revision.
  • 1987 - Code named "Tortilla".


  • Software - The GIME is emulated in software in the various CoCo 3 emulators.
  • FPGA - The GIME is recreated in virtual hardware in the FPGA systems.


  • GIME-X

Rumored 256 Color Mode

Early system specifications mentioned a 256-color mode, but there is no evidence this ever made it in to production. It may have been present in the early PCB prototypes, and a project is underway to see if this was true.

  • Nick Marentes researched and documented the efforts to determine if a 256-color mode existed in the production GIME chips.
  • Roger Taylor began his Project 256 in November 2021. He sent off several GIME chips to be decapped and imaged so they could be studied to see how they worked.


External Links