When one normally talks about ‘building’ a computer, the ‘building’ process is akin to Lego: blocks specifically designed to be compatible are clicked together in a reasonably idiot-proof manner, then an off-the-shelf operating system is installed. Daniel’s C88 and C3232 systems, by contrast, are built from the ground up: systems built around using an 8×8 or 32×32 LED display as memory and running a unique processor, built from scratch on an FPGA, with its own instruction set architecture.
The smaller C88 came first, and the larger and more complex C3232 – designed with a mode which allows it to run software originally written for the early Manchester Small Scale Experimental Machine (SSEM), or Manchester Baby, without modification – served as a magnum opus for the project. Daniel wasn’t done there, though: a final effort produced the Mini C88, a C88-compatible kit powered by the a low-cost Arduino instead of a more expensive FPGA but boasting near-complete compatibility with the original.
While Daniel has yet to release the kit, a simulator provides a hint of what it’s like to use the C88 or Mini C88: programs are entered into the system one bit at a time using physical toggle-switches, then executed for display on the LED matrix. Examples include simple animations, pseudorandom number generation, and mathematical calculations, while the real C88 can also be connected to external hardware via a general-purpose input-output (GPIO) port missing from the Mini C88.
I’ve long been a fan of Daniel’s creations, and am lucky enough to own a Mini C88 of my very own – but even for those who haven’t caught the systems being demonstrated at various Maker Faires and related events, I’d recommend reading the piece to see just how clever the project really is.
You can see the feature in full by downloading the Creative Commons licensed magazine from the official website, or pick up a copy in print from your nearest newsagent or supermarket.