A Multicore ZX Spectrum

From the blog of [telmomoya] we found his latest project: a hardware based multicore solution for a ZX Spectrum Emulator. It’s not the first time we feature one of his builds, last year we was working on a ARM Dual-Core Commodore C64. Luckily for Speccy fans, it seems a ZX Spectrum project was just unavoidable.

At its heart is the EduCIAA NXP Board, a Dual Core (M4 & M0) 32-bit microcontroller, based on the NXP LPC4337. It’s an Argentinan-designed microcontroller board, born from an Argentinian academic and industry joint venture. [telmomoya] took advantage of  the multicore architecture by running the ZX Spectrum emulator on M4 core and generating the VGA signals with M0 core. This guarantees that the VGA generation, which is rather time-sensitive, remains isolated from emulation and any task running on other core. The VGA sync is via polling and using DMA GPIO the RGB signals can be up to 256 colors. To store the 48 kb VGA frames one AHB32 and one AHB16 memory IC are used.

On the software side, [telmomoya] adopted Aspectrum, a ZX Spectrum Emulator fully written in C, modified to his needs. Overall, the project faced many challenges and issues, like COLOR VGA generation (with GPIO DMA), TFT SPI low fps, Inter Process Communications and bus sharing.

Can you try to name all the games in the demonstration video?

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Power For An Amstrad Spectrum

If you were an American child of the early 1980s then perhaps you were the owner of a Commodore 64, an Apple II, or maybe a TRS-80. On the other side of the Atlantic in the UK the American machines were on the market, but they mostly lost out in the hearts and minds of eager youngsters to a home-grown crop of 8-bit micros. Computer-obsessed British kids really wanted Acorn’s BBC Micro, but their parents were more likely to buy them the much cheaper Sinclair ZX Spectrum.

Sinclair Research was fronted by the serial electronic entrepreneur [Clive Sinclair], whose love of miniaturization and ingenious cost-cutting design sometimes stretched the abilities of his products to the limit. As the 8-bit boom faded later in the decade the company faltered, its computer range being snapped up by his great rival in British consumer electronics, [Alan Sugar]’s Amstrad.

The Amstrad Spectrums replaced the rubber and then shaky plastic keys of the Sinclair-era machines with something considerably more decent, added joystick ports and a choice of a built-in cassette deck or one of those odd 3″ floppy disk drives for which Amstrad seemed to be to only significant customer. For that they needed a more capable power supply offering a selection of rails, and it is this unit that concerns us today. [Drygol] had a friend with an Amstrad-made Sinclair 128K Spectrum +2 with a broken power supply. His solution was to wire in a supply retrieved from a small form factor PC that had all the requisite lines, and for safety he encased it in an improbably huge piece of heat shrink tubing.

Wiring a PSU to a DIN plug for a retro computer is not an exceptional piece of work in itself even if it’s tidily done and nice to see older hardware brought back to life. What makes this piece worth a look instead is the teardown of what is a slightly unusual footnote to the 8-bit home computer story. We’re shown the familiar Z80 and support chips with the Spectrum edge connector and modulator on a through-hole board with a piece of cutting edge tech for a 1980s home computer, a single SMD chip unusually mounted nestled in a hole cut in the board.

Amstrad eventually stopped making Spectrums in the early 1990s, having also tried the Sinclair name on a spectacularly awful PC-compatible home computer. [Clive Sinclair] continued to release electronic products over the following decades, including a portable computer, the last of his trademark miniature radio receivers, and an electric bicycle accessory. Amstrad continue to make computers to this day, and [Alan Sugar] has achieved fame of a different sort as host of the UK version of The Apprentice. He has not yet become Prime Minister.

We’ve featured another Amstrad Spectrum +2 losing its tape deck for a slimmer machine. On that note, the Spectrum wasn’t Amstrad’s only entry in the 8-bit market, and we’ve also shown you a compact clone of their CPC464. As for [Drygol], he’s featured here several times. His mass-restoration of Commodore 64s for instance, or bringing a broken Atari ST back from the dead.

Making a Spectrum Analyzer the Wrong Way on an ATtiny85

Everyone’s a critic, but it’s hard to argue with success. And that’s exactly what [agp.cooper] has with his ATtiny85-based spectrum analyzer devices.

The “normal” way to build a spectrum analyzer is to collect a bunch of samples and run a Fast Fourier Transform (FFT) on them all in one shot. As the name implies, the FFT is fast, and the result is the frequency components of the sampled data. [agp.cooper]’s “wrong” way to do it takes the Goertzel algorithm, which is used for detecting the intensity of a particular frequency, and scanning across the frequency range of interest. It’s a lot slower than a single FFT but, importantly for the ATtiny85 that he implements this on, it’s less demanding of the RAM.

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Custom Media Player Helps Hacker’s Autistic Son

Getting to play with technology is often the only justification a hacker needs to work on a build. But when your build helps someone, especially your own special-needs kid, hacking becomes a lot more that playing. That’s what’s behind this media player customized for the builder’s autistic son.

People generally know that the symptoms of autism cover a broad range of behaviors and characteristics that center around socialization and communication. But a big component of autism spectrum disorders is that kids often show very restricted interests. While [Alain Mauer] doesn’t go into his son [Scott]’s symptoms, our guess is that this media player is a way to engage his interests. The build came about when [Alain] was unable to find a commercially available media player that was simple enough for his son to operate and sturdy enough to put up with some abuse. A Raspberry Pi came to the rescue, along with the help of some custom piezo control buttons, a colorful case, and Shin Chan. The interface allows [Scott] to scroll through a menu of cartoons and get a preview before the big show. [Scott] is all smiles in the video below, and we’ll bet [Alain] is too.

Pi-based media player builds are a dime a dozen on Hackaday, but one that helps kids with autism is pretty special. The fact that we’ve only featured a few projects aimed at autistics, like this 2015 Hackaday Prize entry, is surprising. Maybe you can come up with something like [Alain]’s build for the 2016 Hackaday Prize.

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Spectrum Painting on 2.4 GHz

Give a software-defined radio (SDR) platform to a few thousand geeks, and it’s pretty predictable what will happen: hackers gotta hack. We’re only surprised that it’s happening so soon. Spectrum Painter is one of the first cool hacks to come out of the rad1o badge given out at the CCCamp 2015. It makes it dead-simple to send images in Hellschreiber mode on a few different SDR hardware platforms.

What we especially like about the project is its simplicity. Don’t get us wrong, we’re tremendous fans of GNURadio and the GNURadio Companion software radio hacking environment. But if you just want to do something simple, like send a picture of a smiley-face, the all-capable GNURadio suite is overkill.

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Hackaday Links: May 10, 2015

Here’s a cool crowdfunding campaign that somehow escaped the Hackaday Tip Line. It’s a remote control SpaceShipOne and White Knight. SpaceShipOne is a ducted fan that has the high-drag feathering mechanism, while White Knight is a glider. Very cool, and something we haven’t really seen in the scratchbuilding world.

[Sink] has a Makerbot Digitizer – the Makerbot 3D scanner – and a lot of time on his hands. He printed something, scanned it, printed that scan… you get the picture. It’s a project called Transcription Error.

Keurig has admitted they were wrong to force DRM on consumers for their pod coffee cups.

The Apple ][, The Commodore 64, and the Spectrum. The three kings. Apple will never license their name for retro computer hardware, and there will never be another computer sold under the Commodore label. The Spectrum, though… The Sinclair ZX Spectrum Vega is a direct-to-TV console in the vein of [Jeri Ellisworth]’s C64 joystick doohickey.

Infinity mirrors are simple enough to make; they’re just one mirror, some LEDs, and another piece of glass. How about a 3D infinity mirror? They look really, really cool.

Here’s the six-day notice for some cool events: Hamvention in Dayton, OH. [Greg Charvat] will be there, and [Robert] is offering cold drinks to anyone who mentions Hackaday. If anyone feels like scavenging for me, here’s a thread I created on the Vintage Computer Forum.  Bay Area Maker Faire is next weekend. Most of the rest of the Hackaday crew will be there because we have a meetup on Saturday night

Hackaday Links: May 3, 2015

Everybody loves How It’s Made, right? How about 3D printers? The third greatest thing to come out of Canada featured Lulzbot in their most recent episode. It’s eight minutes of fun, but shame the puns weren’t better. Robertson drives and the Avro Arrow, if you’re wondering.

Speaking of 3D printers, a lot of printers are made of aluminum extrusion. Has anyone tried something like this? It’s an idea that’s been around for a while but we can’t seem to find anyone actually using 3D printed extrusion.

CastARs are shipping out, and someone made a holodeck with retroreflective material. It’s an inflatable dome that’s attached to a regular ‘ol tent that works as a positive pressure airlock. If you’re looking to replicate this, try it with hexagons and pentagons. That should be easier than the orange-slice gores.

For some reason we can’t comprehend, USB ports are now power ports. There’s still a lot of stuff that uses 9 and 12V, and for that there’s the USB 912. It’ll work better with one of those USB battery packs.

Want to see what the Raspberry Pi 2 looks like with a Flir? NOQ2 has you covered.

Remember the Speccy? In the manual, there was an exercise left to the reader: reproduce [Mahler]’s first symphony with the BEEP command. It took a Raspberry Pi (only for synchronizing several Speccys), but it’s finally done.