The Electric Vehicles Of EMF Camp: A Sinclair C5, (Almost) As It Should Have Been

July 4, 2018 by Jenny List 40 Comments

Most Hackaday readers will have heard of [Clive Sinclair], the British inventor and serial entrepreneur whose name appeared on some of the most fondly-recalled 8-bit home computers. If you aren’t either a Sinclair enthusiast or a Brit of a Certain Age though, you may not also be aware that he dabbled for a while in the world of electric vehicles. In early 1985 he launched the C5, a sleek three-wheeler designed to take advantage of new laws governing electrically assisted bicycles.

The C5 was a commercial failure because it placed the rider in a vulnerable position almost at road level, but in the decades since its launch it has become something of a cult item. [Rob] fell for the C5 when he had a ride in one belonging to a friend, and decided he had to have one of his own. The story of his upgrading it and the mishaps that befell it along the way are the subject of his most recent blog post, and it’s not a tale that’s over by any means.

The C5 was flawed not only in its riding position, the trademark Sinclair economy in manufacture manifested itself in a minimalist motor drive to one rear wheel only, and a front wheel braking system that saw bicycle calipers unleashed on a plastic wheel rim. The latter was sorted with an upgrade to a disc brake, but the former required a bit more work. A first-generation motor and gearbox had an unusual plywood housing, and the C5 even made it peripherally into our review of EMF Camp 2016, but it didn’t quite have the power to start the machine without pedaling. Something with more grunt was called for, and it came in the form of a better gearbox which once fitted allowed the machine to power its way to the Tindie Cambridge meetup back in April. Your scribe had a ride, but all was not well. After a hard manual pedal back across Cambridge to the Makespace it was revealed that the much-vaunted Lotus chassis had lived up to the Sinclair reputation for under-engineering, and bent. Repairs are under way for the upcoming EMF Camp 2018, where we hope we’ll even see it entering the Hacky Racers competition.

Indiegogo Calls Time On The ZX Vega

June 7, 2018 by Jenny List 15 Comments

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

June 2, 2018 by Jenny List 10 Comments

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.

Clive Sinclair, The Other Author

April 12, 2018 by Jenny List 51 Comments

A reasonable selection of the Hackaday readership will have had their first experiences of computing on an 8-bit machine in a black case, with the word “Sinclair” on it. Even if you haven’t work with one of these machines you probably know that the man behind them was the sometimes colourful inventor Clive (now Sir Clive) Sinclair.

The finest in 1950s graphic design, applied to electronics books.

He was the founder of an electronics company that promised big results from its relatively inexpensive electronic products. Radio receivers that could fit in a matchbox, transistorised component stereo systems, miniature televisions, and affordable calculators had all received the Sinclair treatment from the early-1960s onwards. But it was towards the end of the 1970s that one of his companies produced its first microcomputer.

At the end of the 1950s, when the teenage Sinclair was already a prolific producer of electronics and in the early stages of starting his own electronics business, he took the entirely understandable route for a cash-strapped engineer and entrepreneur and began writing for a living. He wrote for electronics and radio magazines, later becoming assistant editor of the trade magazine Instrument Practice, and wrote electronic project books for Bernard’s Radio Manuals, and Bernard Babani Publishing. It is this period of his career that has caught our eye today, not simply for the famous association of the Sinclair name, but for the fascinating window his work gives us into the state of electronics at the time.

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Someone’s Made The Laptop Clive Sinclair Never Built

January 21, 2018 by Jenny List 42 Comments

The Sinclair ZX Spectrum was one of the big players in the 8-bit home computing scene of the 1980s, and decades later is sports one of the most active of all the retrocomputing communities. There is a thriving demo scene on the platform, there are new games being released, and there is even new Spectrum hardware coming to market.

One of the most interesting pieces of hardware is the ZX Spectrum Next, a Spectrum motherboard with the original hardware and many enhancements implemented on an FPGA. It has an array of modern interfaces, a megabyte of RAM compared to the 48k of the most common original, and a port allowing the connection of a Raspberry Pi Zero for off-board processing. Coupled with a rather attractive case from the designer of the original Sinclair model, and it has become something of an object of desire. But it’s still an all-in-one a desktop unit like the original, they haven’t made a portable. [Dan Birch has changed all that, with his extremely well designed Spectrum Next laptop.

He started with a beautiful CAD design for a case redolent of the 1990s HP Omnbook style of laptop, but with some Spectrum Next styling cues. This was sent to Shapeways for printing, and came back looking particularly well-built. Into the case went an LCD panel and controller for the Next’s HDMI port, a Raspberry Pi, a USB hub, a USB to PS/2 converter, and a slimline USB keyboard. Unfortunately there does not seem to be a battery included, though we’re sure that with a bit of ingenuity some space could be found for one.

The result is about as good a Spectrum laptop as it might be possible to create, and certainly as good as what might have been made by Sinclair or Amstrad had somehow the 8-bit micro survived into an alternative fantasy version of the 1990s with market conditions to put it into the form factor of a high-end compact laptop. The case design would do any home-made laptop design proud as a basis, we can only urge him to consider releasing some files.

There is a video of the machine in action, which we’ve placed below the break.

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Romania’s 1980s Illicit DIY Computer Movement

November 7, 2017 by Steven Dufresne 52 Comments

In Western countries in the early 1980s, there was plenty of choice if you wanted an affordable computer: Apple, Atari, TRS-80, Commodore and Sinclair to name a few. But in communist-ruled Romania, mainly you’d find clones of the British Sinclair ZX Spectrum, an 8-bit computer built around the Zilog Z80A, using a CRT TV as display and a BASIC interpreter as UI. The Cobra was one such Romanian Sinclair clone. However, most people couldn’t afford even that, which lead to hackers building their own versions of the Cobra.

Making these clones was highly illegal. But that didn’t stop students at the Politehnica University of Bucharest. They made them for themselves, family and friends, and even sold them at well under market price. To keep people from building radio transmitters, the Communist government kept electronics prices high. So instead, parts smuggled from factories could be paid for with a pack of cigarettes.

Look inside an old Apple II and you’ll see a sea of chips accomplishing what can be done with only a few today. The Cobra clones looked much the same, but with even more chips. Using whatever they could get their hands on, the students would make 30 chips do the job of an elusive $10 chip. No two computers were necessarily alike. Even the keyboards were hacked together, sometimes using keys designed for mainframe computers but with faults from the molding process. These were cleaned up and new letters put on. The results are awesome hacks which fit right in here on Hackaday.

Sadly though, it often takes harsh necessity to make a culture where these inspiring hacks thrive in the mainstream. Another such country which we’ve reported on this happening in is Cuba, which found the necessity first when the U.S. left Cuba in the 60s and again when the Soviet Union collapsed in the 90s, reducing the availability of many factory produced items needed for daily life, and creating a DIY society.

Build A Calculator, 1974 Style

November 6, 2017 by Jenny List 10 Comments

Last month we touched upon the world of 1970s calculators with a teardown of a vintage Sinclair, and in the follow-up were sent an interesting link: a review of a classic Sinclair calculator kit from [John Boxall]. It’s a few years old now, from 2013, but since it passed us by at the time and there was clearly some interest in our recent teardown, it’s presented here for your interest.

It seems odd in 2017 that a calculator might be sold as a kit, but when you consider that in the early 1970s it would have represented an extremely expensive luxury purchase it makes some sense that electronics enthusiasts who were handy with a soldering iron might consider the cost saving of self-assembly to be worthwhile. The £24.95 price tag sounds pretty reasonable but translates to nearly £245 ($320) in today’s terms so was hardly cheap. The calculator in question is a Sinclair Cambridge, the arithmetic-only predecessor to the Sinclair Scientific we tore down, and judging by the date code on its display driver chip it dates from September 1974.

As a rare eBay find that had sat in storage for so long it was clear that some of the parts had suffered a little during the intervening years. The discrete components were replaced with modern equivalents, including a missing 1N914 diode, and the display was secured in its flush-fitting well in the board with wire links. The General Instrument calculator chip differs from the Texas Instruments part used in the Scientific, but otherwise the two calculators share many similarities. A full set of the notoriously fragile Sinclair battery clips are in place, with luck they’ll resist the urge to snap. A particularly neat touch is the inclusion of a length of solder and some solder wick, what seems straightforward to eyes used to surface-mount must have been impossibly fiddly to those brought up soldering tube bases.

The build raises an interesting question: is it sacrilege to take a rare survivor like this kit, and assemble it? Would you do it? We’d hesitate, maybe. But having done so it makes for a fascinating extra look at a Sinclair Cambridge, so is definitely worth a read. If you want to see the calculator in action he’s posted a video which we’ve put below the break, and if you need more detail including full-resolution pictures of the kit manual, he’s put up a Flickr gallery.

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