This site is dedicated to etherforth, a variant of colorForth running entirely in GreenArrays' GA144 multi-computer chip. It is a programming language, operating system, and development environment in one.

Charles H. Moore, the inventor of FORTH programming language, and designer of GA144 chip started etherforth development around 2010. He documented progress of this project in his Weblog, and demonstrated system capabilities at SVFIG Forth Day meetings in 2011 and 2012. At the beginning of 2013 he put this project aside.

Chuck gave me the latest version of his source code (dated Jan 9, 2013) in 2017. To fully comprehend his code took some time, and a lot of experimenting. Nevertheless, I gradually added all missing parts, and by mid 2020 I had etherforth development system complete and running.

Presented here is version 1.01a of etherforth. It comes in two variants. One is compiled using a PC (within colorForth environment) and loaded into host chip of GA eval board via USB. Once loaded, the system runs independently of the PC. Other method of using etherforth is to compile and burn system image into an onboard SPI flash memory. Apart from how the system gets booted up (from a PC or from the onboard flash memory) the two variants are the same, except that the latter one makes etherforth a truly standalone system.

Purpose of this web site is to collect all available information about etherforth. You'll find here a detailed description of what is etherforth, what hardware you need, software source code, a manual explaining how to use it and how to write your own code, and tutorials on etherforth and GA144 programming in general. In download section you'll find links to colorForth development environment provided by GreenArrays, and etherforth source files. The site is intended for all those interested in this unusual system either out of curiosity or because of intention to build the system for their own use and entertainment.

Programming GA chips is a wonderful experience but it requires good knowledge of how these chips work. When the tutorials section is finished, there will be a primer on GA144 programming to help novices to get started. Nonetheless, studying GreenArrays' documentation is indispensable if you wish to enjoy working with their chips to the fullest. Unless you are perfectly familiar with GA chips I strongly recommend to study thoroughly GreenArrays' documentation you can find here.

Although the information available on this site is provided "as is" I'll be happy to answer questions pertaining to etherforth and GA144, and help those who wish to implement the system on their own. Feel free to send questions or comments to