Tang Nano 20K FPGA replaces chips on a TRS-80 CoCo 1/2 to make it a CoCo 3

A Tang Nano 20K FPGA-based retrofit lets owners of the original TRS-80 Colour Computer models 1 and 2 approximate an upgrade to the more capable CoCo 3. Designed by Felipe Antoniosi, the system uses daughterboards fitted into sockets for motherboard chips, with the FPGA reproducing key CoCo 3 hardware. It adds paged memory support for up to 512 KB and enhanced graphics while retaining compatibility with the original graphics chip. The project also provides HDMI and analog video outputs and improved sound, extending a vintage computer’s capabilities without replacing it with a wholly separate machine.

The modification is substantial, prompting a broader question about how far modernization can go before a classic computer stops feeling authentic. Some enthusiasts value the FPGA as a practical way to get a more powerful CoCo, much as an owner might have welcomed such an upgrade in the 1980s. Others wonder whether the added computing power makes the original machine little more than a peripheral to an FPGA, or whether full emulation would be more coherent. The discussion also distinguishes upgrading a computer as a useful tool from preserving its original engineering: for people who prize period-specific technology, replacing its hardware logic with modern components may diminish the appeal, even if the result is more capable.