Custom PC, Issue 206

Custom PC, Issue 206This month’s Hobby Tech feature takes a look at the recently-unearthed Nine Tiles prototype ROM for the ZX Spectrum by installing it on a ZX Spectrum Next, dramatically improves the flexibility of the FLIR ETS320 thermal inspection camera, and pores over classic computer commercials courtesy of coffee-table tome Do You Compute?.

First, the prototype ROM. In my review of the ZX Spectrum Next in Custom PC Issue 202, I mentioned that it’s possible to create new “machine personalities” – both by replacing the read-only memory (ROM) files used in Spectrum mode and by loading new cores onto the FPGA at the machine’s heart. Shortly prior to the ZX Spectrum Next’s launch, the Centre for Computing History received a trove of artefacts from Nine Tiles – including a prototype ZX Spectrum which was used to develop a ROM which never actually made it onto the publicly-launched machines.

The Centre had negotiated to make the ROM image available for free download for educational and academic purposes, which gave me an opportunity to load the ROM onto the ZX Spectrum Next and create the Nine Tiles Prototype as a usable machine personality. What followed was a process of debugging and reverse-engineering in order to make the ROM functional on the Next – a process which, I’m pleased to say, was wholly successful.

The FLIR ETS320, meanwhile, was reviewed back in Issue 201 – and one of my biggest complaints was its incredibly short focal length, meaning that it is only possible to analyse a very small part of a given circuit board under the thermal sensor. While the camera platform is capable of rising up, anything above 70mm away from the device on test is too blurry to be of use – unless, that is, you take advantage of a 3D-printed tool to manually adjust focus. The improvement is stark, as thermal images published in the piece demonstrate.

Finally, Do You Compute? is a book which looks not at the history of computing but at the history of selling computing – specifically, as the subtitle makes clear, “from the Atomic Age to the Y2K bug.” Put together by Ryan Mungia and Steven Heller, the book is a fantastic chronological walk through the shift in computers being for governments and big businesses to any businesses and eventually the home user.

It also has a major flaw, and it’s not one caused by the authors: Apple, for reasons unspecified, declined to provide permission for its adverts to be reproduced in the book. With Apple having been at the very forefront of the personal computing revolution, and well-known for iconic adverts from its 1984 Superbowl commercial to “Think Different” and “Rip Mix Burn,” it leaves a real hole in the book.

Custom PC Issue 206 is available now in supermarkets, newsagents, and online with global delivery via the official website.

Custom PC, Issue 201

Custom PC Issue 201This month’s Hobby Tech column takes a look at the upcoming Mooltipass BLE hardware password dongle, FLIR’s ETS320 thermal camera for electronics testing, and has a word from Eben Upton about the cost-reduced Raspberry Pi 4 Model B 2GB single-board computer.

First, the Mooltipass BLE. I reviewed the Mooltipass Mini – itself a successor to the original, bulkier Mooltipass – back in Issue 168: a compact, metal-encased device, the Mooltipass Mini holds your passwords in encrypted storage accessible only using a smartcard and four-digit hexadecimal PIN. I’ve been using the Mooltipass Mini with great success since its launch, but it’s always a bit of a pain to use with a mobile device – requiring a USB cable and OTG adapter.

The Mooltipass BLE aims to fix that, by integrated a Bluetooth Low Energy radio. While it can still operate in tethered USB mode, the Bluetooth radio plus internal battery give it a newfound freedom – though my experience is as a beta tester, with finalised and fully-functional firmware still under active development before the device goes on open sale.

The FLIR ETS320, by contrast, is a fully-finished piece of hardware. Regular readers will know that I’ve long been an advocate of thermal imaging analysis for revealing the secrets of electronic devices, and the ETS320 is a considerable upgrade from my usual FLIR C2: the 80×60 resolution thermal sensor of the C2 is replaced by an impressive 320×240 version in the ETS320, at the cost of a dramatically reduced maximum focus distance. I’d also like to thank FLIR for its partnership: the ETS320 has become a permanent fixture in my toolkit, and will be used alongside the C2 for thermal analysis in future hardware reviews.

Finally, the Raspberry Pi 4 Model B 2GB. While the board itself isn’t new, its pricing is: Raspberry Pi Trading recently decided, prompted by falling RAM prices, to retire the 1GB model and make the 2GB model the new entry point into the family. “2GB is a much more viable desktop platform than 1GB,” RPT chief executive Eben Upton told me in an interview for the column. “1GB is great for embedded, but for a desktop platform it’s just a little bit too tight. What it means is that we’re now back to having a really viable desktop machine at our signature price point.”

The full column is available now in Custom PC Issue 201 at your local newsagent, supermarket, or for global delivery from the official website.

Custom PC, Issue 146

Custom PC Issue 146This month’s Hobby Tech column begins with a look at a topic that has been close to my heart for a number of years now: thermal imaging, and how it can be applied to the field of hobbyist electronics and technology review. If that weren’t interesting enough, there’s also a review of the Novena open-hardware all-in-one desktop, and a look at a little-known bug-fix applied to Sinclair’s classic ZX81 microcomputer.

For years, I’ve wanted a thermal camera. Recently, the price of cameras has plummeted and I was finally able to justify – just about – the cost of the entry-level Flir C2. While it takes a while to get used to thinking in resolutions of 80×60 – the total resolution of the Flir Lepton thermal imaging module featured in the C2 – I’ve been having no end of fun capturing thermal data on everything from single-board computers to my cat.

In the column, though, I argue for the application of thermal imaging in the hobbyist realm. With smartphone-connected thermal cameras now available in the low-hundreds, and a broken-out Lepton module the equal of the one found in the C2 available for just £160, a thermal imaging sensor is no longer the preserve of well-heeled professionals. I’ve found mine useful for tasks from finding hot-spots on a board design to spotting heatsinks which were not properly mated to the components below.

When I wasn’t playing with the thermal camera, I was playing with the Kosagi Novena. Born from the mind of noted hacker Andrew ‘Bunnie’ Huang, the Novena is remarkable: it’s a truly open computer, with everything from the firmware through to the board designs being published under an open-source licence. Loaned by UK hobbyist electronics shop oomlout, I was sad to give the crowd-funded Novena back – despite an ARM-based processor outclassed by even the cheapest of x86 laptop parts.

Finally, the ZX81. I’ve been clearing out much of my classic computer collection as I shift to a smaller office, and while I had to get rid of my rather rare Sinclair ZX81 I wanted to record its existence for posterity. From the very original production run, this machine boasted the ‘cockroach’ – a bug-fix for a fault in the ROM implemented in hardware, with a hand-soldered board attached to the top of the system’s CPU. It’s a jarring sight, and one that I was privileged to see in person: only a handful of cockroach-model ZX81s, fixed while the company waited for corrected ROM chips to arrive, exist and they’re all externally identical to non-cockroach models.

All this, plus a wide selection of stuff written by people who aren’t me, is available now from your local newsagent, supermarket, or digitally via Zinio and similar services.