Netflix Drops ZX Spectrum Homebrew Title Nohzdyve

The dark, dystopian future is ever-present in the Netflix show Black Mirror, but the latest release in the series, Bandersnatch, presents a decidedly different narrative. Bandersnatch is a branching story that follows the fictional events of a garage-programmer named Stephan who develops the titular game, Bandersnatch, for the Tuckersoft company set in 1980s England. The whole thing plays out as a choose-your-own adventure game fit straight off the Sega CD (albeit with actual full motion video) by allowing watchers to pick what happens next in the story. Not one to miss a cross-promotional opportunity, Netflix also released a playable ZX Spectrum homebrew title, Nohzdyve, developed by a friend of Hackaday, [Matt Westcott].

Keen viewers of Bandersnatch were able to ascertain that the screeching sound at the end of the show when loaded into a ZX Spectrum would display a QR code. That in turn led to a real website for the fake Tuckersoft company (thankfully in HTML). The website itself showcases the fictional company’s software library and upcoming releases, but it also took things a step further. The duality of Bandersnatch is carried over to the website as there are branching paths for those that remove ‘www’ from the URL. Doing so reveals Tuckersoft’s website from an alternate timeline where Bandersnatch was never created, however, a downloadable copy of Nohzdyve in a .tap file is there for the taking.

The Nohzdyve game itself is a vertically scrolling action game that uses the ZX Spectrum’s garish color palette to great effect. Racking up a high score in the game can be done via emulator (for example Speccy) or for the most authentic experience, on real hardware. This may be the best reason to fire up a tape drive in a while, but for those seeking the less-analog approach there is always this gameplay footage from Mr. Tom FTW’s channel:

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Fail of the Week: How Not to Design an RF Signal Generator

We usually reserve the honor of Fail of the Week for one of us – someone laboring at the bench who just couldn’t get it together, or perhaps someone who came perilously close to winning a Darwin Award. We generally don’t highlight commercial products in FotW, but in the case of this substandard RF signal generator, we’ll make an exception.

We suppose the fail-badge could be pinned on [electronupdate] for this one in a way; after all, he did shell out $200 for the RF Explorer signal generator, which touts coverage from 24 MHz to 6 GHz. But in true lemons-to-lemonade fashion, the video below he provides us with a thorough analysis of the unit’s performance and a teardown of the unit.

The first step is a look at the signal with a spectrum analyzer, which was not encouraging. Were the unit generating a pure sine wave as it should, we wouldn’t see the forest of spikes indicating harmonics across the band. The oscilloscope isn’t much better; the waveform is closer to a square wave than a sine. Under the hood, he found a PIC microcontroller and a MAX2870 frequency synthesizer, but a conspicuous absence of any RF filtering components, which explains how the output got so crusty. Granted, $200 is not a lot to spend compared to what a lab-grade signal generator with such a wide frequency range would cost. And sure, external filters could help. But for $200, it seems reasonable to expect at least some filtering.

We applaud [electronupdate] for taking one for the team here and providing some valuable tips on RF design dos and don’ts. We’re used to seeing him do teardowns of components, like this peek inside surface-mount inductors, but we like thoughtful reviews like this too.

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HOPE XII: Time Travel with Software Defined Radio

It’s easy to dismiss radio as little more than background noise while we drive.  At worst you might even think it’s just another method for advertisers to peddle their wares. But in reality it’s a snapshot of the culture of a particular time and place; a record of what was in the news, what music was popular, what the weather was like, basically what life was like. If it was important enough to be worth the expense and complexity of broadcasting it on the radio, it’s probably worth keeping for future reference.

But radio is fleeting, a 24/7 stream of content that’s never exactly the same twice. Yet while we obsessively document music and video, nobody’s bothering to record radio. You can easily hop online and watch a TV show that originally aired 50 years ago, but good luck finding a recording of what your local radio station was broadcasting last week. All that information, that rich tapestry of life, is gone and there’s nothing we can do about it.

Or can we? At HOPE XII, Thomas Witherspoon gave a talk called “Creating a Radio Time Machine: Software-Defined Radios and Time-Shifted Recordings”, an overview of the work he’s been doing recording and cataloging the broadcast radio spectrum. He demonstrated how anyone can use low cost SDR hardware to record, and later play back, whole chunks of the AM and shortwave bands. Rather than an audio file containing a single radio station, the method he describes allows you to interactively tune in to different stations and explore the airwaves as if it were live.

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Indiegogo Calls Time On The ZX Vega

It has been an exciting time to be a retro computer enthusiast in recent years, and the availability of affordable single board computers, systems-on-chip, and FPGAs have meant that retro hardware could be accurately reproduced or emulated. A host of classic micros have been reborn, to delight both the veterans who had the originals, and a new crop of devotees.

Today we have news of the impending demise of one of the higher-profile projects. The ZX Vega+ is a handheld Sinclair Spectrum console bearing the Sinclair name that came with an impeccable pedigree in that it had the support of the man himself. It seemed like a good proposition on the crowdfunding site Indiegogo, and when it made its debut there in early 2016 it attracted over half a million pounds worth of backing in short order. Things soon went sour though, with reports of a falling-out within Retro Computers, followed by multiple missed deadlines and promises undelivered over the last couple of years. With little sign of either the money or the console itself, it seems Indiegogo have now lost patience and will be sending in the debt collectors to recover what they can. Whether the backers will see any of their money is unclear.

It’s fair to say that the ZX Vega saga has been a tortuous and rather sordid one, out of which few players emerge smelling of roses. In a way though it is entirely in keeping with the spirit of the 8-bit era, as the period from the late 1970s onwards was littered with the financially bare corpses of dubiously run companies in the home computer industry. Meanwhile if you are hankering for a Vega it should be easy enough to create one for yourself, as Retro Computers Ltd admitted that under its skin was a copy of the FUSE software emulator. We suspect that most Hackaday readers could take a Raspberry Pi and a suitable LCD, pair them with a 3D-printed case and an 18650 cell, and be playing Manic Miner in no time. Far simpler than this convoluted Spectrum project!

Bringing Back A Spectrum’s Rails

The Sinclair ZX Spectrum was to most Brits the computer to own in the early 1980s, it might not have had all the hardware features of its more expensive competitors but it had the software library that they lacked. Games came out for the Spectrum first, and then other platforms got them later. If you didn’t have a rubber keyboard and a Sinclair logo, you were nothing in the playground circa 1984. That low price though meant that in true Sinclair tradition a number of corners had been cut in the little micro’s design. Most notably in its power supply, all the various rails required by the memory chips came from a rather insubstantial single-transistor oscillator that is probably the most common point of failure for these classic machines.

[Tynemouth Software] had an Issue 2 Spectrum with a missing -5V rail, and has detailed both the power supply circuit used on these machines and the process of faultfinding and repairing this one. A single transistor oscillator drives a little ferrite-spool transformer from which the various supplies are rectified and filtered. Similar circuits appear in multiple generations of Sinclair hardware, where we might nowadays use a little switching regulator chip.

We’re taken through the various stages of faultfinding this particular circuit, and the culprit is found to be a faulty Zener diode. It’s certainly not the last dead Spectrum that will cross an enthusiast’s bench, but at least in this case, the fault was less obtuse than they sometimes can be in this much-loved but sometimes frustrating machine.

Sinclair enthusiasts might also appreciate the great man’s earliest work.

Putting a Poor Man’s Vector Analyzer Through Its Paces

If anything about electronics approaches the level of black magic, it’s antenna theory. Entire books dedicated to the subject often merely scratch the surface, and unless you’re a pro with all the expensive test gear needed to visualize what’s happening, the chances are pretty good that your antenna game is more practical than theoretical. Not that there’s anything wrong with that — hams and other RF enthusiasts have been getting by with antennas that work without really understanding why for generations.

But we’re living in the future, and the tools to properly analyze antenna designs are actually now within the means of almost everyone. [Andreas Spiess] recently reviewed one such instrument, the N1201SA vector impedance analyzer, available from the usual overseas sources for less than $150. [Andreas]’s review does not seem to be sponsored, so it seems like we’re getting his unvarnished opinion; spoiler alert, he loves it. And with good reason; while not a full vector network analyzer (VNA) that will blow a multi-thousand dollar hole in your wallet, this instrument looks like an incredible addition to your test suite. The tested unit works from 137 MHz to 2.4 GHz, so it covers the VHF and UHF ham bands as well as LoRa, WiFi, cell, ISM, and more. But of course, [Andreas] doesn’t just review the unit, he also gives us a healthy dose of theory in his approachable style.

[The guy with the Swiss accent] has been doing a lot of great work these days, covering everything from how not to forget your chores to reverse engineering an IoT Geiger counter. Check out his channel — almost everything he does is worth a watch.

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Crowdfunding Is Now A Contract Between Company And Backer

Kickstarter is not a store. Indiegogo is not a store. Crowdfunding is not buying something — you’re merely donating some money, and you might get a reward for your pledge. Caveat emptor doesn’t apply, because there is no buyer, and no one can figure out what the correct Latin translation for ‘backer’ is. These are the realities that have kept Indiegogo and Kickstarter in business, have caused much distress in people who think otherwise, and have been the source of so, so many crowdfunding follies.

Now, finally, crowdfunding is being legally recognized as a store. The Register reports a court in England has ruled against Retro Computers Ltd and said it had formed a contract of sale with crowdfunding backer Rob Morton. For one person, at least, for one of their pledges, Indiegogo is a store.

The crowdfunding campaign in question is the Retro Computers’ Sinclair ZX Spectrum Vega Plus, a small device not unlike the Commodore 64 direct to TV joysticks. The Spectrum Vega simply plugs into your TV, reads an SD card, and plays old ‘speccy games. Clive Sinclair, the genius who brought us the Spectrum, strange flat CRTs, and a host of other inventions, was involved in this campaign. In the years since the campaign ended, there have been numerous updates and Retro Computers still says they intend to deliver the device. Morton, apparently fed up with the delays, brought a suit against Retro Computers for the grand sum of £584: £85 for the Spectrum pledge, £5 for shipping, and the remainder for travel expenses and lost wages for the court date.

District Judge Clarke of Luton County Court heard the case and ruled against Retro Computers, finding there was a contract of sale between Morton and Retro Computers Ltd.. Evidence included a number of copies of Morton’s order, a document the judge pointed out as saying ‘this order’ and not ‘this pledge’. Additionally, the judge found the fine print on Indiegogo does not negate a contract of sale; there was still an implied agreement between Morton and Retro Computers, and Retro Computers had breached the contract by not delivering a Spectrum.

It should go without saying that this finding does not apply to every project on Indiegogo, it does not apply to Kickstarter, and nor does it apply to every crowdfunding campaign. This does not even apply to all backers of the Spectrum Vega Plus. Still, there are hundreds of thousands of backers for crowdfunding projects that haven’t received what they paid for, and if nothing else this story gives just a little bit of satisfaction to anyone that’s still waiting on an undelivered product.