HackSpace Magazine, Issue 5

HackSpace Magazine Issue 5My contribution to the latest issue of HackSpace Magazine is a detailed look at the ZX Spectrum Next, an open-hardware reimplementation of the Sinclair ZX Spectrum microcomputer with a wealth of improvements and enhancements.

Officially licensed from the current owner of the Spectrum rights – Sky In-Home Services, oddly enough, which requires only that a portion of any proceeds are donated to charity – the ZX Spectrum Next builds on the original with a Z80 implementation on a field-programmable gate array (FPGA) which can be run in accelerated mode at up to 14MHz, up to 2MB of memory, SD card storage, built-in joystick ports, crystal-clear HDMI video output, four-channel AY sound, support for original Spectrum keyboards or modern PS/2 keyboards, and even optional real-time clock, ESP8266 Wi-Fi, and Raspberry Pi Zero-based co-processor add-ons.

Despite these upgrades – and more I haven’t mentioned, including a brand-new operating system dubbed NextOS, 256-colour display modes, and hardware sprite support – the ZX Spectrum Next also boasts full backwards compatibility with software and hardware designed for the original Spectrum family, which is something of an impressive achievement given the relatively modest resources available to its creators following a successful crowdfunding campaign for its production.

The ZX Spectrum Next reviewed here, though, isn’t quite the finished article. Provided to backers eager to get their hands on the device as early as possible, the board-only ZX Spectrum Next Issue 2A is aimed primarily at developers. It also comes with an annoying design flaw, which was discovered post-review: a missing capacitor which can cause stability issues when coupled with low-quality power supplies. The finalised Issue 2B, its creators promise, will include the missing capacitor along with a keyboard and chassis housing designed by Sinclair’s long-term industrial designer Rick Dickinson.

For a full look at the ZX Spectrum Next, you can pick up Hackspace Magazine Issue 5 at your nearest supermarket, newsagent, or as a free download under the Creative Commons licence at the official website.

Custom PC, Issue 176

Custom PC Issue 176This month’s Hobby Tech column takes a look at the fascinating ZX Spectrum Next, the impressive RetroFlag NesPi case for the Raspberry Pi, and the book Britsoft.

First, the ZX Spectrum Next. The product of a highly successful crowdfunding campaign that drew in around three quarters of a million pounds from backers across the world, the ZX Spectrum Next is exactly what it sounds like: the next entry in the long-running Sinclair Spectrum family, long after even its most ardent fans had given up hope. Although based around ‘soft’ cores running on a central FPGA, the Next isn’t an emulator: the open design is entirely compatible with every piece of software or hardware you can throw at it, complete with accessories designed for the original Spectrum. It’ll even fit in a 16K/48K chassis, if you don’t mind drilling a few extra holes.

Those holes, you see, are needed for just some of the Next’s shiny new features: a pair of joystick ports, HDMI and VGA video outputs, and even the ability to insert a Raspberry Pi Zero into a special header for use – once the software has been written – as a co-processor, or as it was known at the time a “copper.” There’s room for up to 2MB of RAM, triple-chip FM synthesis, even Wi-Fi network support – though a design flaw discovered shortly after the review went to print means that anyone with the early-release Model 2A will need to solder a small capacitor onto the voltage regulator for full reliability, an issue fixed with Model 2B onward.

The NesPi, by contrast, is a lot simpler. At its heart, it’s a plastic case into which you can install a Raspberry Pi B+, 2, or 3. Its designers, though, have decided to create something a little different, and the Nintendo Entertainment System ‘inspired’ housing also includes daughterboards which offer four front-facing USB ports – two where the controllers would connect and another two under the ‘cartridge’ flap – along with working power and reset buttons. The Ethernet port is also brought to the front, for no readily apparent reason, while the dedicated power board includes a header for an optional cooling fan.

Finally, Britsoft is a book that has been on my shelves awaiting review for a little while now. A Read Only Memories publication, this impressive hardback tome gathers interview content originally created for the 2014 documentary From Bedrooms to Billions charting the rise of the British computer games industry. You’d be hard pushed, off the top of your head, to think of a luminary of the era not included in the title’s impressive 420 pages, and I had but one real complaint: the layout of the book is easier on the eye than the brain, often making it difficult to follow which speaker is talking and which topic you’re reading.

All this, and the usual collection of stuff by other people, is available now at your nearest newsagent, supermarket, or digitally via Zinio and similar services.

Custom PC, Issue 174

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.