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.

Custom PC, Issue 109

Custom PC, Issue 109This month’s Custom PC magazine is a rather special issue: it’s the only place you’ll find a step-by-step photographic feature on how to build Sinclair Computer’s ZX81 kit outside a time-travelling newsagent with good stock of 1981-era magazines.

Having purchased a ZX81 kit from a rapidly-dwindling stock, I knew that I would be building it rather than keeping it unassembled and its purpose in life unfulfilled. I also knew that I’d be trying my damnedest to get a magazine to pick up the story, for the simple reason that there aren’t many of these things left and I wanted as many people to enjoy a little glimpse of history as possible. Thankfully, Custom PC editor Ben Hardwidge agreed – and even put the feature on the top bar of this month’s cover.

The build was an interesting look back at how the face of computing has changed: while Sinclair’s kits required the user to know which end of a soldering iron was safe to hold, modern computing – for all its exponential increase in complexity and power – is relatively simple, requiring little more knowledge than required to put the square peg in the square hole.

It was also a chance for me to exercise my photojournalistic skills, rather than just my writing skills. Using my somewhat outdated Pentax digital SLR, a light tent, two halogen lights and a table-mounted stand, I was able to snap some surprisingly detailed photos using nothing more than the standard 18-55mm kit lens. These photos illustrate every single step, and the art department has done a great job on the layout of the feature.

As well as the exclusive ZX81 build, which has generated considerable interest, this month’s magazine includes my usual Mobile Tech Watch column. This month, I looked at the difference between the x86 and ARM instruction set architectures, and why Intel is going to have its work cut out to compete with ARM in the mobile space.

Finally, this issue includes my review of the Arduino Leonardo, kindly provided by Oomlout. Is it worth the upgrade from the Uno, and are there any downsides to the new single-chip approach taken by the Arduino team in its design? Better pick up a copy of Custom PC and find out, hadn’t you?

Custom PC Issue 109 is available in all good newsagents, most bad ones, and digitally via the Zinio service.