Will Green Wants to Teach You Computer Building From the Ground Up with Isle, a RISC-V FPGA Project

FPGA developer and open hardware maker Will Green has announced a new project, Isle — which aims to teach people how to build their very own RISC-V computer, implemented on a choice of low-cost field-programmable gate array (FPGA) development boards.

"I'm creating a computer called Isle," Green explains of the project. "Isle is a simple, modern computer — an open design that encourages tinkering, experimentation, and doing your own thing. By simple, I mean that one person can understand the whole system. Modern in that we use contemporary components, development tools, and standards."

The Isle computer itself is based around a 32-bit processor core implementing the free and open source RISC-V instruction set architecture, combined with a 2D graphics engine, a Unicode-compatible text mode, sound, SD Card storage, keyboard and mouse inputs, expansion options, and support for a custom operating system dubbed "Isle OS" and its custom-written "simple software" packages.

"Everything is as homegrown as practical while retaining interoperability with the wider world," Green notes. "For example, the graphics system is a custom design, but it works with regular TVs and computer displays. I've chosen a RISC-V CPU, rather than design my own architecture. RISC-V lets us use the full panoply of modern programming languages and development tools while remaining simple. We'll develop software in parallel with our hardware, beginning with RISC-V assembler and adding high-level languages later."

What Green isn't doing, however, is designing any custom boards; instead, Isle is designed to be implemented on affordable FPGA development boards: the Machdyne Lakritz, Digilent Nexys Video, or larger versions of the Radiona ULX3S. "With a simulator," Green notes, "you don't even need a dev board; you can run your hardware on your existing PC or Mac with free software."

The Isle project is a work-in-progress; at the time of writing Green had published the initial documentation on the graphics hardware, with the CPU to follow in future updates. Everything is being developed in the open, with all documentation and source code published on GitHub under the permissive MIT license.

Those looking to make their own Isle can follow along on Green's website.