SpeccyX - ZX Spectrum Next Handheld

Posted: Sep 01, 2018
By: Dan Birch

This project has nothing to do with the official Spectrum Next Kickstarter or the Spectrum Next team. This is simply an attempt by myself to create a handheld Spectrum using 3D printing technology and a smaller version of the Spectrum Next board that I backed on Kickstarter.

It's been a while since building a laptop case for my Spectrum Next board and since then I have learnt a lot more about the Spectrum Next board, enough in fact to give me the confidence to try and build a smaller version of the board. Something that would be suitable for creating a hand-held Spectrum.

Another Spectrum Handheld?

Spectrum games can already be played on a large variety of phones, tablets, Nintendo DS, Sony PSP, Rasberry Pi etc via software emulation. There was of course the infamous Vega + which, initially promised to deliver a dedicated Spectrum handheld experience but didn't exactly work out well for the people who backed that project on Indiegogo (One of those backers was myself).

The handheld I wanted to create would be a dedicated Spectrum device, it will be compatible with Spectrum Next games and most importantly it will be real hardware rather than a software emulator.

A Big Calculator Meets a GameBoy

Here are some designs for my handheld Spectrum. I've been calling it the SpeccyX for now and as you can see it looks like a cross between a big calculator and a Gameboy! It is fairly large, probably about the size of a small Tablet which I'm happy with. There may be scope to make a smaller version in the future, but this is dependant on me finding a smaller screen that delivers an acceptable image.

ZX Spectrum Next Handheld Design 1

ZX Spectrum Next Handheld Design 2

The SpeccyX

  • Dimensions: 127mm x 178mm x 18mm
  • LCD: 5" HDMI (Spectrum screen area ex. border 71mm x 52mm)
  • Controls: Nintendo DS D-Pad and button assemblies
  • Keyboard: 40 Buttons, 9mm x 8mm each in size
  • Sound: Stereo speakers/headphone socket with volume dial
  • Storage: Micro SD (spring loaded)
  • Firmware/OS: Standard Spectrum Next firmware and NextZXOS

It's a Spectrum Next

Spectrum Next Board

Whilst emulators are fine for a low cost retro gaming experience, I prefer my retro games to be running on real hardware. In this case the awesome ZX Spectrum Next. I received my Next board back in December 2017 and since then have learnt enough about it to be able to re-produce the board in a much smaller footprint. Some things such as the Expansion Connector and Ear (tape loader) socket have been removed completely. This is a handheld where games are loaded via SD card so there isn't much need for these.

The Keyboard

I've never been a huge fan of virtual keyboards in other Spectrum handhelds, so for the SpeccyX I wanted to have a small keyboard containing all the keys found on the original rubber keyed Spectrum. It is a simple micro switch driven keyboard and is not meant for fast typing, rather its sole purpose is to enable navigating game menus quickly, selecting the options you want and getting the game started the way the games were originally designed to be operated.

ZX Spectrum Next Handheld Design 3

The Game Controls

When it comes to the D-Pad and the 4 game buttons, I decided to simply use Nintendo DS D-pad and button assemblies. These can be found on Ebay for a couple of ££'s and as you can imagine with a Nintendo device they feel perfect for the job.

A

The D-Pad and the 2 buttons ("A" and "B") map to the Kempston joystick. With 2 additional buttons ("X" and "Y") above that map to the "Enter" and "Space" keys. What if the game doesn't support a Kempston joystick I hear you say? There is an additional slide switch to the right of the Green M1 button which toggles the D-Pad/"A" & "B" buttons between Kempston and Sinclair which should cater for most games.

If a game only has a redefine keys option, again, the Sinclair option can be used as these simply map to the keys "6" to "0" anyway and along with the "X" and "Y" buttons this should give enough buttons for most games.

Anybody who is familiar with the Spectrum Next (and earlier Spectrums) will know the menus in the OS are driven by the cursor keys, however by installing this nifty driver made by Paul Land the D-Pad (in Kempston mode) can be used to navigate the menus and load games instead of the traditional Spectrum cursor keys.

The Screen

This is where things get complicated! As the SpeccyX is based on the Specturm Next and because it must also be compatible with the Spectrum Next FPGA core/firmware I am constrained by the 2 video outputs of the Next, namely VGA and HDMI. Having these 2 options for connecting the handheld to a small LCD screen should make things easy (in theory). The reality though is a little more challenging.

VGA

Finding a small VGA LCD (5 Inch or less) that can display a minimum of 640x480 is tricky. For a start, most of these (4:3) screens have a lot of weight to them and tend to be a little on the power-hungry side - not good for a battery driven handheld. Once a reasonably sized screen has been found, the likelihood is that the image will not be displayed correctly and will most likely not be centred on the screen. This is due to the Next not generating a VGA signal that these small screens can digest. Of all the screens I have tried that feature VGA inputs, none of them have been acceptable.

Sure, it's possible to sort the image out via the built-in screen menu's that allow fine tuning of the vertical/horizonal positioning but this isn't ideal when you have to do this every time you turn the device on. There must be a better option.

HDMI

Thankfully the Next also has HDMI output too and this is more tolerant of small LCD's. After testing different screens I settled on a 5 Inch screen I found on Ebay which also came with a HDMI driver board:

5" HDMI

Although there are smaller screens, many of them simply do not support anything higher than 480x320 which, when connected to the Next, results in a blurry image. In an ideal world the FPGA core would be modified to output a resolution to match these small screens, however for now I can live with the larger screen.

Spectrum Next Handheld 5 Inch LCD

UPS For the Spectrum Next Handheld

The Custom Spectrum Next PCB

As already mentioned, I received my Spectrum Next board back in December 2017 and since then have been re-creating a smaller version of it. Due to the lack of any schematic (due after the final Kickstarter units are delivered I believe) I removed the FPGA and worked out which trace went where. Now I have a smaller version of my Next board.

Here is the SpeccyX assembled just waiting for the back panel to be fitted. A total of 5 PCB's make up the handheld:

  • Mini Spectrum Next board
  • Keyboard/D-pad input board
  • HDMI driver board
  • Battery/power supply board
  • External connector board

Inside the Portable Spectrum Next

All Done

For the 3D printing I initially used my trusty Makerbot Replicator 2 to create the initial prototype cases. This enabled me to quickly make changes until the design had evolved into something that would both work and all fit together at the end. The final printed plastic parts are done using Shapeways Premium Versatile Plastic service. I have used Shapeways for many years and they always do a great, high quality job for a reasonable price.

The whole SpeccyX case could easily be 3D printed using the Makerbot Replicator 2 or other home 3D printers, the size of the 3D printed parts will easily fit these printers too.

Here it is all assembled and playing a demo version of Dreamworld Pogie. The keyboard buttons are all black and I will at some point either paint(!) the characters on or maybe use some small stickers.

The finished Handheld Spectrum Next Prototype

The finished Handheld Spectrum Next Prototype 2

The finished Handheld Spectrum Next Prototype 3

How Does it Play?

It feels pretty good to play games on it. The Nintendo DS D-pad/buttons are perfect for playing Spectrum games. The size and weight is on a par with a small tablet and the 3D printed finish is super smooth making it nice to hold (no sharp edges on this handheld). Here are a couple of brief videos of games being played on it. Note that the display quality is perfect, crystal clear, something my recordings/camera do not show that well:

A Quick Play of Target Renegade

Manic Miner

Warhawk

Dreamworld Pogie

Update 17/11/2018

Having tracked down a 3.5" screen capable of 800x600 via HDMI I built a smaller version of the handheld, here are some pictures of the smaller version:

The finished Handheld 3.5

5" VS 3.5" - A Side by Side Comparison

The finished 3.5

Comments

DavidNov 27, 2018 17:50

Are the playable areas of 5" and 3.5" versions equal size? Any plan to sell the SpeccyX handheld? You can count on me 🤗

MattNov 05, 2018 13:43

Drool!! I want one!!

StooNov 02, 2018 16:29

Wow, that's amazing!
What a fantastic job. Nice one.

Asobi Quang DXNov 02, 2018 13:32

Take my money!!!
I had a go with Jim Bagley's SpeccyX at PLAYexpo Blackpool and it was perfect in so many way. Great feeling, excellent screen, good weight. I guess the only thing would be to work out some sort of backlight on the keyboard keys.
Either way, I really want one, to be able to code SpectrumNEXT stuff on the go is a dream come true.

BaggersOct 30, 2018 16:39

What can I say, I love mine it's blooming ( as I don't know who is reading this ) awesome! :D
Yes, Dan, the screen size is Perfect, going smaller I'd say is not an option, the amount of people at the show that said ( and I agree ) it's the right size for our hands!
I took it to the show at Play Expo Blackpool, and it went down amazingly! I'll be taking it to Revival Mini, for anyone who wants to see it in person.

Pascal NobsOct 30, 2018 13:43

I want also a next portable !!!

Rob MortonOct 30, 2018 10:35

I love this too!!! Amazing work! :)

DavidSep 18, 2018 21:58

I need it!

David SaphierSep 17, 2018 21:11

Awesome work Dan!

GlennSep 15, 2018 03:40

This is a smart wonderful thing. I’m thinking team Next could augment their lineup with this piece.

Michael C.Sep 10, 2018 06:02

Nice job! I would say that the screen is the perfect size! Smaller enough to remain hand-held, big enough to actually see what’s going on.

Angel (adesilva70)Sep 06, 2018 12:19

Hi Dan, when I see creations like this or like the ZX Spectrum Next Laptop case I have to congratulate you for making me jelous of not being so skillfull in hardware electrinics.
Please help spectrum enthusiasts selling your builds.

DeonSep 05, 2018 14:02

Brilliant! I wish I had just a half of your smarts. I have been a VG programmer for 24 years from PS to PS4, and I would trade all my experience for just half of your knowledge.

Phoebus DokosSep 05, 2018 13:29

Well another absolutely fabulous build. Great work Dan; thanks also for showing Pogie (new distro has a newer version with sound)

toboSep 05, 2018 12:59

If I wasn't already 'over it' this has the potential to make me even more furious that the Vega+ team couldn't deliver.

But, I'm over it.

I am.

Jim BagleySep 05, 2018 11:10

That's awesome Dan, are you going to make more? I'd love one!

Pascal Nobs (skysier)Sep 05, 2018 09:08

I'm very interested in that.. but I can't do, I haven't posibility to do that.. If you want sell an prototype.. it will be good. I think a lot of people would have that..
Good Job

ZXNextSep 05, 2018 08:45

Hi, Do you plan to sell the extra Next Board that you build? (only next board). I also made a small version of Next board you can see picture from here.
[IMG]http://i67.tinypic.com/k0lzpz.jpg[/IMG]

MiguelSep 05, 2018 07:55

People's ingenuity never ceases to amaze me. If you alone can master something as beautiful as this in only a few months, why couldn't those idiots at RCL complete the Vega+ in 2+ years? Anyway, we'll done Dan. I feel very inspired by your ability and wish/hope that one day you'll share the particulars with us, so that we can also create our own versions. Good job mate.

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