Tag Archive for Linux

Custom PC, Issue 179

Custom PC Issue 179This month’s Hobby Tech column takes a look at an open-source microcontroller-driven hobbyist oscilloscope and a book which aims to document art in video games, while also walking readers through the rather handy trick of setting up a reverse SSH tunnel.

First, the tutorial. Since Code42 announced that CrashPlan Home, my chosen off-site backup solution, was being discontinued, I’ve been looking into alternatives. A Raspberry Pi with a USB hard drive and a copy of Syncthing installed does the job nicely, except for the issue of management: once it’s off-site, I’d have to configure someone else’s router to forward a port so I can SSH into it. An easier alternative: a reverse SSH tunnel.

Where a traditional SSH connection goes from local device to remote host, a reverse tunnel goes from remote device to an intermediary device – in my case, a home server on my own network. Your local device then also connects to said intermediary device, and you have full access to the remote device regardless of whether or not it’s behind one or more firewalls or even whether you know its public-facing IP address.

The first of the reviews, meanwhile, is a little cheeky: while the device on test is based on the JYE Tech DSO138 open-source oscilloscope design and firmware, I’ve been using a clone rather than an original – having spotted it on offer during an Amazon sale and been unable to resist a bargain. While the conclusions I draw on the scope’s functionality and usability apply equally to both, a first-party JYE Tech version is likely to feature better build quality and certainly includes better support.

Finally, my review of the coffee table tome – yes, another one – Push Start: The Art of Video Games is one of those rare occasions where I’ve been disappointed by what should have been a product aiming for a very low bar. While the full-colour hardback publication includes plenty of high-quality pictures, it also includes some extremely low-quality screenshots as well – particularly noticeable at the beginning where vector games are captured as bitmaps using MAME’s default ultra-low resolution, and at the end where tell-tale artefacts show the use of third-party JPEG images rather than first-party captures. Worse still is the limited accompanying text, which is riddled with errors.

The latest Hobby Tech is available now from newsagents, supermarkets, and electronically via Zinio and similar digital distribution services.

The MagPi, Issue 68

The MagPi Issue 68The launch of a hardware refresh for the low-cost yet surprisingly-capable Raspberry Pi single-board computer is always a great opportunity to take stock of how the project has progressed since its launch six years ago, and the result is this: a special cover feature for The MagPi celebrating the release of the Raspberry Pi 3 Model B+, or Pi 3 B+ to its friends.

Following roughly the same format as my cover feature for the launch of the Raspberry Pi 3 from March 2016, and my cover feature for the Pi Zero’s launch back in November 2015, my multi-page feature begins with an overview of the board highlighting its key new features with high-resolution call-out photography: the new Broadcom BCM2837B0 system-on-chip which dispenses with the old plastic package for a new direct-die layout protected by a metal heatspreader; the new dual-band 2.4GHz and 5GHz Wi-Fi and Bluetooth radio module; a Pi Zero-inspired ground plane antenna, which boosts wireless performance still further; a Power over Ethernet (PoE) header for the optional PoE HAT; gigabit Network connectivity; and a custom-designed power management integrated circuit (PMIC) which improves regulation and assists with the clockspeed increase to 1.4GHz.

Taking a brief pause for a quick getting-started guide for those new to the Raspberry Pi, the feature then gets into its stride with a full suite of benchmarks across two pages. Measuring everything from CPU and memory performance to Ethernet throughput, power draw, and Wi-Fi signal quality, the benchmarks don’t just cover the Pi 3 B+ and its immediate predecessor; the benchmarks compare the new board to every single mainstream model of Raspberry Pi in the project’s history, all the way back to the original Model B from the initial pre-production run. If you’ve ever wondered how things have improved over time, this feature will let you know exactly that.

A further two pages are taken up by my interview with Raspberry Pi Foundation co-founder Eben Upton, who first introduced me to the project all those years ago. Diving into the changes and improvements made in the Pi 3 B+’s design, which is the work of engineer Roger Thornton, the interview also includes several behind-the-scenes images and – because I can never resist the opportunity – a thermal imaging analysis demonstrating how the new packaging and thicker PCB help the Pi 3 B+ deal with heat dissipation, despite its faster clock speed compared to the hot-running Pi 3.

To read through the full feature, which also includes a more detailed getting-started guide and ten project ideas which take advantage of the board’s increased power, head to your local newsagent, supermarket, or download the issue digitally under the permissive Creative Commons licence from the official website.

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.

Custom PC, Issue 172

Custom PC Issue 172That this month’s Hobby Tech column includes the review of a single-board computer should come as no surprise; that it’s a Windows 10 machine, though, certainly shakes things up a bit – as do a guest appearance by my trusty Cambridge Computers Z88 and an interview with Indiegogo’s Joel Hughes on the topic of crowdfunding.

The DFRobot LattePanda isn’t a new device, but it’s new to me. While I’ve probably reviewed more single-board computers than any other device category – and written the book on more than one – the LattePanda stands out from the crowd for two reasons: it uses an Intel Atom processor with considerable grunt, and it runs Microsoft’s Windows 10 Home operating system. Add in to that an on-board Arduino-compatible microcontroller and you’ve got a very interesting system indeed – and one which only got more interesting when I popped it under the thermal camera.

My interview with Indegogo’s Joel Hughes, meanwhile, took place in the spacious hall of Copenhagen’s former meat-packing district as part of the TechBBQ event. “We want to democratise funding as much as possible and level the playing field for great ideas,” he told me, before I threw a few tricky questions about some high-profile campaigns that had perhaps fallen short of greatness – or even mediocrity. “I don’t feel, the majority of the time, that it’s malicious,” he claimed on the topic of campaign operators who fail to keep their backers in the loop on post-fundraising progress. “I think they’re busy doing their own thing and almost forget about the comment section a little.”

Finally, the Cambridge Computers Z88. Although it’s been in my possession for many years, has a bag-friendly A4 footprint, and runs for a full day’s work on a set of double-A batteries, I’ve shied away from using Uncle Clive’s portable for serious work owing to the difficulties in actually getting documents off its internal memory and onto something more modern. The purchase of a PC Link II kit and some clever open-source software, though, has solved the problem, and if you see me out and about at events don’t be surprised if I’m taking notes on a rubber-keyed classic.

All this, plus a bunch of other stuff, is available at your nearest newsagent, supermarket, or digitally via Zinio and similar distribution services.

Custom PC, Issue 171

Custom PC Issue 171This month’s Custom PC magazine has a bumper crop for fans of Hobby Tech: a four-page shoot-out of do-it-yourself handheld games consoles on top of my usual five-page column, which this time around looks at setting up Syncthing on a Raspberry Pi, building the Haynes Retro Arcade Kit, and my time running a soldering workshop at the Open Source Hardware User Group (OSHUG) UK OSHCamp gathering.

The workshop first: organiser Andrew Back got in touch with me shortly before the OSHCamp workshop day, held in Hebden Bridge as part of the annual Wuthering Bytes technology festival, was due to take place. The scheduled soldering workshop was at risk, he explained, as the person due to run it was no longer available. I was happy to help, and I’m pleased to report a great day was had by all assembling Cuttlefish microcontroller kits – despite the use of some particularly ancient soldering irons with tips which appeared to be made of freshly-hewn coal!

The Haynes Retro Arcade Kit feels like a device which could have been in the DIY console shootout, but it wouldn’t have fared well. Designed by Eight Innovation and slapped with the Haynes brand, the Retro Arcade Kit is a fiddly and distinctly unrewarding soldering kit which ends up as a particularly basic version of Pong. The coin activation system is its only redeeming feature: two pieces of thick solid-core wire sit side by side, and are shorted out by an inserted metal coin to start a fresh game. Not an original trick, but one well implemented – if you ignore the terrible instructions and poor build quality.

Syncthing, meanwhile, has been a mainstay of my toolbox for years. An open-source project designed to keep files on two or more computer systems synchronised, Syncthing is built with security and convenience in mind – and works a treat on the Raspberry Pi. Given that I was needing to find a new home for my off-site backups anyway, as my regular provider CrashPlan is ceasing its cheapest product line, it seemed natural to write up the process of turning a Pi and a USB hard drive into an off-site backup destination.

Finally, the four-page DIY console shoot-out is a reprint of the same feature as it appeared in PC Pro Issue 277 in mid-September. As before, four Arduino-compatible devices are covered: the Gamebuino, MAKERbuino, Creoqode 2048, and Arduboy.

All this, and the usual selection of things written by others, can be found at your nearest newsagent, supermarket, or electronically via Zinio and similar distribution services.

Custom PC, Issue 169

Custom PC Issue 169My Hobby Tech column for this month’s Custom PC features three reviews: the CubieBoard 6 single-board computer, the Digilent OpenScope MZ open-hardware multi-function oscilloscope, and a book detailing the rise and fall of gaming legends the Bitmap Brothers.

The CubieBoard 6, to start, was kindly provided by low-power computing specialist New IT. Despite its high version number, the device felt like a blast from the past as soon as I opened the box: it’s based on almost exactly the same form factor as the original CubieBoard and its successor the CubieBoard 2, after which creator CubieTech moved towards bulkier designs with up-to-eight-core processors. A return to form is no bad thing: CubieTech boasts that the CubieBoard 6 can be used as a drop-in replacement for most CubieBoard 1 and 2 projects.

For the review, I ran the device through the usual raft of benchmarks and gave it a direct comparison to the Raspberry Pi 3 with which it competes. One interesting shift from the norm, though, was in thermal imagery analysis which revealed that the CubieBoard’s SATA-to-USB bridge chip draws considerable power even when no SATA device is connected – something that would have been difficult to ascertain any other way.

The OpenScope MZ, meanwhile, is a very different beast – though, technically speaking, also a single-board computer of sorts. The successor to Digilent’s original OpenScope, the OpenScope MZ is a hobbyist- and education-centric open-hardware dual-channel oscilloscope with additional functionality as a function generator, power supply, and logic analyser. Where it differs from its competition, though, is in the presence of a Wi-Fi chip which allows you to connect to the device remotely – which, coupled with the browser-based software used to drive the thing makes it compatible with everything from Windows desktops to a Raspberry Pi or smartphone running the Linux variant of your choice.

Finally, The Bitmap Brothers Universe is a fantastic coffee table tome charting the history of the titular giants of gaming familiar to any Amiga owner present or former. Written based on painstaking interview work by Duncan Harris and published by Read Only Memories, the bulk of the book is in single-colour print with reproduced concept art and illustrations breaking up the prose; the exception comes in the form of colour plates on glossy black paper, which use a series of neat post-process effects in an attempt to simulate their appearance on an old cathode-ray tube (CRT) display – the way they were originally meant to be seen.

All this, and the usual interesting things written by others, can be found on the shelves of your local supermarket, newsagent, or digitally via Zinio and similar distribution services.

Custom PC, Issue 168

Custom PC Issue 168This month’s Hobby Tech column is taken up with a trio of reviews covering the pretty darn impressive Mooltipass Mini hardware password manager, Automattic’s Blog in a Box distribution for the Raspberry Pi, and Mark Hardisty’s A Gremlin in the Works.

Starting with the latter, A Gremlin in the Works is another fantastic coffee-table book from retro computing publisher Bitmap Books (the founder of which, Sam Dyer, I interviewed back in Custom PC Issue 136). Written by Mark Hardisty based on exhaustive interviews – and retaining the question-and-answer style of the transcripts, making for an accurate rendition of the subjects’ thoughts but a slightly tiresome read – the two-volume book chronicles the rise and fall of gaming pioneer Gremlin Graphics. As a massive fan of Gremlin’s output – to this day the intro music to Hero Quest brings joy to my heart, and I blame my sweet tooth on a Zool addiction – A Gremlin in the Works is a book I’d long been looking forward to reading, and I’m pleased to say it didn’t disappoint.

Blog in a Box, meanwhile, is an interesting beast. At its heart, it’s a single-purpose GNU/Linux distribution for the Raspberry Pi created by Automattic as a means of making it easier for people to run the WordPress blogging platform from the device. It’s not provided as a downloadable drive image, as with most distributions, though; instead, Automattic has written a cross-platform program which customises various settings – title, passwords, email accounts, things like that – and configures them so the Pi is ready to rock on first boot. It’s a neat idea, but one which still needs polish: I found the Linux version failed to run properly on my Ubuntu 16.04 desktop, and several features promised by the tool were disabled when the Pi actually started up. It’s a tool with promise, though, and I look forward to revisiting it should Automattic release an update.

Finally, the Mooltipass Mini. The brainchild of Mathieu Stephan, the Mooltipass Mini builds on its non-Mini predecessor to create a pocket-sized hardware password safe for all your accounts – or, at least, as many as will fit in 8Mb (1MB) of internal memory. The Mooltipass Mini is a tool for the adequately paranoid: passwords, though not usernames, are stored in the device’s internal memory under AES-256 encryption with the private key located on a removable smart card itself locked with a four-hexadecimal-character PIN. When a password is required, its entry can be found on the screen and the Mooltipass does its best impression of a USB keyboard by typing the account details in on your behalf – or, when the optional software is installed, filling in forms in browser windows automatically upon manual confirmation on the device itself.

Having long advocated for the use of password managers to promote high-quality password use and discourage password reuse, the Mooltipass Mini is a near-perfect companion. It addresses the majority of the problems with traditional password managers, like how to keep the encrypted database accessible while preventing its theft. While there are undeniable issues, such as the £61 (inc. VAT) retail price and the need to buy two so you have a backup to use if the primary one fails, it has become a part of my security arsenal – and one I feel comfortable using thanks to the project’s open-source nature for both the software and underlying hardware.

All this, and a whole mess of other things written by people who aren’t me, is available in the latest Custom PC Magazine from your nearest supermarket, newsagent, or electronically via Zinio and similar digital distribution services.

Custom PC, Issue 167

Custom PC Issue 167This month’s Custom PC features a look at the effect of compiler optimisation on applications plus reviews of Google’s AIY Voice Kit for the Raspberry Pi family and Jimmy Wilhelmsson’s Generation 64.

The tutorial, to begin, stemmed from investigations I was carrying out into Google’s Guetzli perceptual JPEG encoder. Having cut my teeth in computing back when every byte – never mind kilobyte – really counted, I have a soft-spot for compression both lossy and lossless. Over the years I’ve toyed with a range of compression algorithms, from LZMA and Robert Jung’s ARJ through to the clever if short-lived Fractal Image Format (FIF). Like most, though, I eventually settled on two popular formats for my image compression needs: JPEG where lossy compression is acceptable and PNG where it isn’t.

Guetzli aims to cut the file size of JPEG files by around a third for no apparent loss in perceived image quality. That was enough to pique my interest, but it comes at a cost: a runtime of minutes per megapixel to recompress each image. As an open-source project, Guetzli is provided in source-code form – so I began to play with the optimisation options available in the GNU Compiler Collection (GCC) to see if I couldn’t speed things up.

As readers of my column will discover, I could indeed speed things up – cutting the time taken to compress the small sample image provided with Guetzli from 14.3 seconds using Google’s precompiled binary version down to just 9.56 seconds. Although not an exhaustive guide to compiler optimisation in general nor even GCC-specific options – a topic which would take a book, rather than a couple of magazine pages, to cover adequately – hopefully the write-up of my experiments will help shine a light on the gains that can be made, the potential pitfalls of excessive optimisation, and the benefits of open-source distribution.

The Google AIY Voice Kit, meanwhile, is something quite special: an add-on for the Raspberry Pi family of microcomputers which, in essence, turns them into a somewhat cut-down version of the company’s Google Home voice-activated assistant platform. Initially distributed with The MagPi Magazine as a cover-mounted giveaway, the kit should soon be available for purchase by the general public – and it’s definitely worth seeking one out.

The kit itself centres around a Hardware Attached on Top (HAT) add-on board, which includes servo and motor control, connectivity for an arcade-style button, and links to a break-out board with a pair of MEMS microphones. Combined with some simple software and a link to Google’s cloud computing platform, the AIY Kit can be made to respond to your natural-language queries or even control external hardware via voice recognition – with some major caveats regarding how often you can use it before you need to start handing over cash for the voice recognition platform.

Finally, Generation 64. Originally written in Swedish by Jimmy Wilhelmsson and with design by Kenneth Grönwall, Generation 64 investigates the influence the Commodore 64 had on the Swedish computing scene – complete with an introduction by the founder of Digital Illusions, also known as DICE, and MOS 6502 creator Chuck Peddle. Translated into English and re-released by Bitmap BooksGeneration 64 is an absolutely fantastic read which I would have otherwise missed had it remained untranslated.

Full details on all of these, plus a bunch more stuff written by people who aren’t me, can be found in Custom PC Issue 167 at your nearest supermarket, newsagent, or digitally via Zinio and rival distribution platforms.

Custom PC, Issue 166

Custom PC Issue 166Readers of my regular Hobby Tech column this month will find a BBC micro:bit-driven tutorial alongside two reviews covering the remarkable Raspberry Pi Zero W microcomputer and the fascinating Delete by Paul Atkinson.

The idea for the tutorial came about while working on a chapter of my upcoming Micro:bit User Guide, and seemed like a perfect fit for the readers of Custom PC Magazine: turning the low-cost yet extremely flexible micro:bit into an addressable USB-connected 5×5 LED matrix and having it display current CPU load in a constantly-updating bar graph. Naturally, the same technique could be used to graph almost anything.

The secret lies in MicroPython’s REPL, an interactive interpreter which can run on the micro:bit and accept commands via the USB serial port. By switching the micro:bit into REPL mode, it can be slaved to another system over USB. The result: the entire program code, written in Python using the serial, time, and psutil libraries, exists purely on the host machine. A quick bit of Blu-tack later, and my monitor was wearing a CPU monitor which worked even when the display was off.

The Pi Zero W, meanwhile, was a device to which I had been looking forward for quite some time. An upgraded version of the original £5 Raspberry Pi Zero microcomputer, the Pi Zero W differs in only one respect: it has a built-in radio module, the same BCM43438 as found on the far larger and more expensive Raspberry Pi 3.

While the addition of the radio module, which offers Bluetooth, Bluetooth Low Energy, and 2.4GHz Wi-FI connectivity, almost doubles the price of the Pi Zero W to £9.60, it’s money well spent. In almost every Pi Zero project I have built, I’ve ended up using a USB OTG adaptor and low-cost USB Wi-Fi dongle to add network connectivity, and having it on-board – even at a slightly higher cost compared to a USB-connected solution – makes life considerably easier.

Finally, Delete. Billed as “a design history of computer vapourware,” Paul Atkinson’s coffee table book is packed with high-quality photographs – and, for the rarer machines, the occasional rescaled JPEG exhibiting unfortunate compression artefacts – covering machines from an upgraded Sinclair QL to a bright yellow IBM that never left the drawing board. Each comes with pages on its history, with interview subjects detailing features and failures alike, and while not all machines were strictly vapourware few are likely to have a place in the average vintage computing collection. In short: if you like old computers you’ll like Delete, which is available now from Amazon and other bookstores under ISBN 978-0857853479.

As always, you can read the whole column and a whole lot more by picking up Custom PC Issue 166 from your nearest supermarket, newsagent, or electronically via Zinio and similar services.

PC Pro, Issue 271

PC Pro Issue 271In this month’s PC Pro Magazine I take a look at possibly the least original product to have ever come out of Asus’ labs: the Raspberry Pi clone known as the Tinker Board.

Designed to help Asus capture a slice of the lucrative maker market, the Tinker Board is a one-for-one feature-and-footprint clone of the Raspberry Pi 3: it’s a roughly credit-card-sized single-board computer with an ARM processor, wired Ethernet, Wi-Fi and Bluetooth radios, four USB 2.0 ports, an HDMI port, analogue audio, Camera Serial Interface (CSI) and Display Serial Interface (DSI) ports, and a 40-pin general-purpose input-output (GPIO) header. So far, so cloned.

Where Asus has tried to improve upon its inspiration is in the raw specifications: the processor, while 32-bit to the Raspberry Pi 3’s 64-bit, is considerably faster; there’s double the memory, a supposedly gigabit network connection which isn’t bottlenecked by a single-channel USB bus, support for 4K video playback, and high-resolution 24-bit 192KHz audio. If all of that were true, it’d be easy to overlook the higher selling price of the Tinker Board compared to the Pi on which it is based.

Sadly, my review didn’t go smoothly. The Tinker Board has hit the market in a parlous state. The 4K video playback is choppy, the GPIO port barely works and none of its features beyond simply toggling a pin on and off are available, hardware accelerated video playback is barely functional, and the ‘gigabit’ Ethernet port no faster than the 10/100Mb port on any standard Raspberry Pi.

To be fair to Asus, the majority of the problems I encountered – bar, possibly, the Ethernet performance – were likely related to the software provided, which appears to be in a very early alpha stage. It’s a device I’ll be keeping to one side in the hope of revisiting it in the future, should Asus ship improved software.

For a full run-down of my experience with the board, pick up the latest PC Pro at your nearest supermarket, newsagent, or electronically on Zinio and other digital distribution platforms.