Homebrew

HackSpace Magazine, Issue 4

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Hackspace Issue 4This month’s HackSpace Magazine includes a four-page spread detailing two projects from the talented Daniel Bailey: the Manchester Baby inspired C88 and C3232 homebrew microcomputers.

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.

Custom PC, Issue 174

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Custom PC Issue 174This month’s Hobby Tech column takes a look at a very special eight-byte – not a typo – microcomputer, walks through turning a spare Raspberry Pi into a Nav Coin-mining cryptocurrency machine, and looks forward to the launch of the ZX Spectrum Next with a look at a deep-dive book detailing the original Spectrum’s neat Ferranti Uncommitted Logic Array (ULA) chip.

First, the Mini C88. Designed by the multi-talented Daniel Bailey as a more affordable version of his C88, swapping the field-programmable gate array (FPGA) on which he implemented his own processor core design for an Arduino Zero and the extremely clever Dynamic Binary Translation (DBT) technique, the C88 is designed to be about as simple as a computer can get. Based on a custom instruction set, the C88 has just eight memory locations of eight bits apiece and is programmed by toggling each bit using a series of pleasingly tactile switches while monitoring the process on the 8×8 LED matrix that serves as its display.

For regular readers, this will all sound familiar: the original FPGA-based C88 and its 32-byte bigger brother the C3232 were the subject of an interview back in Issue 155. While Daniel has still not turned the C88 into a kit you can head out and buy, the Mini C88 is definite progress in that direction – and, as always, anyone interested in the project should hassle him about it on Twitter.

For those with a Raspberry Pi and a desire to play with cryptocurrency, meanwhile, this month’s tutorial will be of definite interest: a guide to turning a Pi into a ‘Stake Box’ for the Nav Coin cryptocurrency. Designed as an alternative to Bitcoin, Nav Coin offers those who run network nodes rewards in the form of a five percent return on their coin holdings when locked up in this manner. Taking less than an hour to set up and requiring nothing more than a low-powered computer, it’s a great way to get involved – and the Nav Coin project itself definitely one to follow.

Finally, while waiting impatiently for my ZX Spectrum Next microcomputer to land – which, I’m pleased to say, has since happened – I enjoyed a re-read of Chris Smith’s excellent The ZX Spectrum ULA: How to Design a Microcomputer. Based on interviews and deep-dive analysis, the book investigates the tricks and techniques which allowed Sinclair Computers to build the ZX Spectrum micro at such a bare-bones cost – which, in turn, was thanks to clever use of an Uncommitted Logic Array (ULA) chip from Scottish electronics giant Ferranti. Effectively a write-once version of the modern FPGA, Ferranti’s ULA saw the number of components in the ZX81 drop to a quarter compared to the ZX80 and is key to how the ZX Spectrum does what it does.

For all this, and a bunch of other interesting things by people who aren’t me, pick up a copy of Custom PC Issue 174 from your nearest supermarket, newsagent, or digitally via Zinio and similar services.

Custom PC, Issue 155

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Custom PC Issue 155This month’s Hobby Tech column features my field report from the Maker Faire UK 2016 event, an interview with my good friend Daniel Bailey about his brilliant homebrew computers, and a review of the Genuino MKR1000 microcontroller.

First, the event. Attending events like the Maker Faire is always a blast, especially as press when you have an excuse to stick your nose into absolutely everything that’s happening. My attendance this year was sponsored by oomlout, a local hobbyist electronics shop and a client for whom I do blog work, as highlighted in a “Sponsored By” call-out over the two-page spread. As for the event itself, you’ll find coverage of everything from DoES Liverpool’s excellent shooting gallery to affordable laser cutters and even the world’s only crowd-funded and wholly amateur manned space programme.

The event also gave me a chance to catch up with Daniel Bailey at the York Hackspace stand, after nearly a year of trying to find a good time to interview him about his impressive homebrew computers. Built on field-programmable gate arrays (FPGAs) and inspired by the classic Manchester Baby, the 8-bit C88 and 32-bit C3232 are incredibly impressive machines – and I can think of no project that better fits with the magazine’s title!

Finally, the MKR1000. Known under the Arduino brand in the US and Genuino brand elsewhere thanks to ongoing trademark disputes, the MKR1000 is Arduino.cc’s answer to the popular Particle Photon Wi-Fi microcontrollers. Featuring a breadboard-friendly layout and integrated 2.4GHz 802.11b/g/n Wi-Fi radio, it represents an interesting new direction for the company – albeit one somewhat hobbled by a high price compared against the competition.

All this, plus the usual raft of interesting things written by people other than me, is awaiting your attention at your local newsagent, supermarket, or electronically via Zinio and similar digital distribution platforms.