Build your own handheld ZX Spectrum with Raspberry Pi Pico

Ken off of the excellent YouTube channel What’s Ken Making isn’t quite over having to spend his childhood in the US where Clive Sinclair’s ZX Spectrum wasn’t available. Fast forward quite a few years, and Ken now has enough bits and pieces in his workshop to make pretty much any computer he damn well wants. Well, he can emulate any computer, anyway.

Peter Misenko (Bobricius to his friends on GitHub and YouTube) is the brain behind the original design for PicoZX, the Raspberry Pi Pico-based Spectrum emulator that inspired Ken. Peter’s short and snappy demo video is above, but we used Ken’s longer build video, below, for more detail as to how he made his.

Reason number one why I personally would argue [are you sure you want to do this — Ed.] that PicoZX might be even better than the original ZX Spectrum: it exists in the now. Reason number two: it’s cuter because it’s smaller, meaning you can also use it as a handheld device and carry it around in your pocket. Reason number three: it’s built on Raspberry Pi Pico.

a white palm-sized PCB with tiny keyboard and small screen
Peter’s original white version

Seeing as Sinclair was a pioneer of affordable home computing with the ZX Spectrum, it’s pretty cool to see a modern day emulator running on a microcontroller which costs just $4.

a black version of the white board featured above
Ken’s homage in black

How is it made?

PicoZX is made up of several custom PCBs, but the Pico and most of the device’s parts are soldered onto one main board. There’s also a face plate, which is largely cosmetic and holds everything in place nicely, and a back plate, which holds the battery and the charge controller. The other four PCBs frame the device around its edges, leaving openings for the SD card and USB ports.

close up of a pico attached to a black pcb with two white hands soldering other parts onto the pcb

A 2.8″ IPS display soldered directly onto the main PCB is the screen for the device. Fifty 7mm tactile switches give the tiny QWERTY keyboard its clickety tactility. PicoZX can also be used with a joystick; Ken showcases an Atari 2600 joystick in his build video.

How does it work?

The Raspberry Pi Pico runs Fruit-Bat’s ZX Spectrum emulator and Jean-Marc Harvengt’s Multi-Computer Machine Emulator (M.CU.M.E). So not only do you have all of the original ZX Spectrum programs at your fingertips, but you can also emulate other devices — such as the Commodore 64, Atari 2600, and ColecoVision — all in one compact handheld device. You’ll have 1980s nostalgia coming out of your ears after a couple of hours with this thing.

the rear plate of the board showing opening for various cables and SD cards

Remembering Clive Sinclair

If you’ve made it to the end of this blog, I’d wager you’re an admirer of Sir Clive Sinclair, the inventor of the ZX Spectrum, who died in 2021. Raspberry Pi co-founder Liz Upton wrote this short but sweet note on the day we heard the news, and the comments section quickly filled with stories from people who had been inspired by his work. Have a look if you’d like to take a scroll down memory lane.

The original and best — Sir Clive with the Sinclair ZX Spectrum

11 comments
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Anders avatar

Well I thought that this was a no-brainer, I simply had to order one. But I’ve run into a list of discrete parts which I’m guaranteed to screw up.

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gus3 avatar

“[T]he RPi wasn’t designed for me, but rather, for kids, schools, and hardware tinkerers who sometimes melt their test units.” — me, 2012

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Ashley Whittaker avatar

OK… you need to tell us how you melted your test unit

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Alan avatar

I know those switches – I’ve used them myself, for projects. They’re awful.
The small surface are makes them OK for occasional use, but TYPING on them is murder. If you plan to use this as a keyboard, find something better.

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Anders avatar

Could have said that about the original Speccy.

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Peter Misenko avatar

no no, this switches are different, switch force is 100gf or 1N, it is near to mechanical keyboard

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Alex avatar

Typing on the original ZX Spectrum was absolutely awful as well, so that’s just authenticity :)

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Liam avatar

I would definitely buy this if it were a commercially-available kit! I don’t really know where or how to get PCBs made.

Also, the GitHub link points to the YouTube page.

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Ashley Whittaker avatar
Charles avatar

Hi,
So does this allow you to store the games on an SD card or similar? I have an original spectrum with loads of original games but… loading’s a pain. Thanks

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What's Ken Making avatar

Yes! You can store games on the microSD card as tape images and load them directly into the device. It also allows you to take snapshots for instant loading of saved state.

Reply to What's Ken Making

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