Isle FPGA Computer

Published 01 Aug 2025 (DRAFT)

Coconut sapling on tropical beach

Be not afeard; the isle is full of noises,
Sounds, and sweet airs, that give delight and hurt not.

Shakespeare, The Tempest

I'm creating a computer called Isle. In this post, I'll introduce you to Isle and hope to inspire you to come on a journey with me and build your own computer. This introduction is still in draft and will evolve as Isle evolves.

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 design isn't finished, so the specification is naturally uncertain, but the following should give you a rough idea.

Isle Specification

Everything is as homegrown as practical while retaining interoperability with the wider world. 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.

I'm not building PCBs or selling hardware; I'm using existing FPGA dev boards and simulators. Think of an FPGA as a giant virtual breadboard or Lego for hardware design. With a simulator, you don't even need a dev board; you can run your hardware on your existing PC or Mac with free software.

Why call it Isle? Aren't islands isolated and cut off? To some extent, the isolation is the point, a refuge from the complex, bloated, engagement-driven technology that we live with every day. But islands are also a place of experimentation and evolution. Look at Darwin's finches, the Komodo dragon, and coco de mer. I hope to inspire an archipelago of small computers, each with its own personality and style, but with enough common ground to share designs and ideas.

I believe graphics and sound are central to what makes computers fun to program and tinker with. I also believe in learning by doing. So, let's introduce the dev boards and get to work on the graphics hardware.

Special thanks to my sponsors who've stuck with me as I've developed this project: Daniel Cliche, David C. Norris, dvir, Justin Finkelstein, kromych, Martin Young, Matt Venn, Michael Doornbos, Paul Sajna, Renaldas Zioma, and those who wish to remain anonymous.

You can sponsor me to support Isle development and get early access to new chapters and designs.

Next step: Dev Boards or Isle Index

PS. It's still early days for the project, and I'm currently focused on hardware. If you're looking to jump into RISC-V and software, you'll need to be patient for a few months.

Isle Contents