Monthly Archives: November 2016

Member project: John’s Tetris Table


Tetris is one of the world’s greatest games. Perhaps one of the reasons Tetris is such a ubiquitous computer game is because you don’t need a particularly high resolution display. You might even say it works better at low resolutions. Perhaps this is what John was thinking when he filled a table with neopixel-like LED strips to create a large low-res display for playing Tetris. If this looks familiar, perhaps you spotted it at the Derby Maker Faire.

John built the table himself from scratch and even gave it York Hackspace branding. He has ten LED strips running the length of the table. They are neopixel-like LEDs which chain together to form a single individually-addressable strip. The ten strips are wired together as one continuous line, snaking its way from one side of the table to the other.


The inside of the table is mostly hollow. The LED strips are stuck to the base and point up towards the perspex lid. To separate the LEDs and make sure that they each illuminate only a small square just above them, John has added a grid of foam walls.


The game is written in python and is running on a Raspberry Pi 2. John’s built a small board with an IO expander for driving the LEDs and reading the buttons.


Of course, there is nothing restricting the table to just running Tetris. At the last hackspace open evening, Nick had a go at writing a snake game. The controls for snake are not so intuitive when you just have four buttons in a straight line, but that adds an element of challenge to it. You can try any of the games or write your own using the tetris table simulator that John wrote as part of this project. All the code for playing in the simulator or on the real hardware is available on github:

Write your own Tetris table games! John will be thrilled to see your pull requests. With potential for two player games, you could get quite creative.

On the subject of creativity, I’ll leave you with this photo of “The Lucky Penny” that definitely isn’t in a hole that was drilled in the wrong place.



You can’t have enough retro computers

I’ve noticed that many members of York Hackspace are quite enthusiastic about old computers. As I look around the hackspace right now, I see that the ratio of modern PCs to retro PCs is about one quarter.

Most of these machines are, or have been, repair projects. I thought I’d share a quick roundup of the various machines people are working on. If nothing else, it’s a great excuse to fill a blog post with pictures of retro tech. As if I needed an excuse. This might take more than one post, so this one is mostly what I’ve been working on.



One particular interesting work in progress involves something like a cross between teletext and the world wide web. I am, of course, talking about ‘Viewdata’. In particular, I’m talking about simulating a prestel service on a modern PC and connecting it, via a sound-card-based phone line simulator, to a Sinclair ZX Spectrum. This is a project that’s been on the backburner for a while with some other members of the space, but we have two fully working ZX Spectrums and each one has a fully working Prism VTX 5000 prestel modem which allows the spectrum to connect to a prestel service. Watch this space, perhaps soon we will be able to tweet from a speccy. I tried to get a photo of it running, but sadly neither of the two TV screens in the space would cooperate. They both have analog tuners, but neither has a remote and the one with buttons on the screen couldn’t be tuned to the right frequency.

One of the two spectrums is mine (the one in the picture). This is one that I got for free from a friend, along with a cassette recorder. It wasn’t working when I got it, so I had to spend a little money on some replacement parts. There was a RAM chip missing and a blown transistor, no wonder it was free. I also decided to upgrade it from the 16k model to the 48k model. The prestel modem came from ebay along with some other stuff that I sold on for a profit. The whole thing was rather cheap.

Another repair project is this Atari 520st. The power supply needs some things fixing, it can’t quite deliver the current required to run the floppy disk drive at the moment. Even if it did, the drive belt is long gone and so we need a replacement. Would you believe that this was found in a skip, along with the monitor and a whole bunch of disks and documentation?



Now here’s one for the IBM keyboard fans. This is an IBM 5155. The “luggable”. It has a proper buckling spring keyboard. This too needs a little bit of work. One of the floppy disk drives is a little dodgy and makes some nasty noises, but it has two, so the worst case scenario is to just use one. It’s got a copy of IBM PC-DOS and also a 20MB hard-disk. The problem is that the hard-disk doesn’t work. That’s why it’s not installed at the moment. The hard-disk controller seems to work though, so the project here is to build an interface to allow something like a USB flash disk to be plugged in where the hard disk would go.




Last but not least for this post, is Luke’s commodore amiga with colour screen. This is also a bit of a rescue project. I’ll have to post more details about this one next time, but for now here is a sneak peek. He’s even got two joysticks for it, and of course he also has the obligatory “I can’t believe it’s not streetfighter” title. I can’t wait to play it. dsc_5475 dsc_5476 dsc_5477


I hope you found that interesting. If you want to help out with one of these projects or just have a look at some of these machines, feel free to come along to the next open meeting. Perhaps I’ll post some more in-depth details of the projects as they progress, if there is any interest.

A multimedia system fit for a hackspace

Being able to leave equipment permanently in place and attached to the walls or ceiling is a luxury we gained when we moved in to our new space. So naturally enough, when we had a projector and an amplifier system lying around doing nothing, it only made sense to give the space a proper multimedia setup.

Projector showing demo image

We put the projector on the ceiling a little while ago, but hadn’t really connected it up until we got the amp and speakers.

With a little bit of planning followed by shopping for the right cables, we now have a setup that should cater for most circumstances. Our projector can now take HDMI, VGA or Mini Displayport (or anything else you can convert to HDMI) with sound provided via a Cambridge audio A1 mk3 Stereo amplifier.

Cambridge audio amplifier and speakers

We can also cast audio to a Raspberry Pi using DLNA. The Pi is connected directly to the amp at the moment and so only does audio, but we plan to get an HDMI switch that will allow us to use the Pi for casting video to the projector without having to sacrifice the wired option.

Raspberry Pi in case, connected to amp

This solution makes it easy to connect almost any device we need to the system. The long HDMI cable ends at a desk on the other side of the room that is convenient for placing a laptop for showing a video or presentation. As the HDMI cable carries both audio and video, this is the only cable we need going to the projector setup, where a converter box splits the HDMI out to VGA and a pair or RCA connectors for audio. Unfortunately the projector doesn’t have any digital inputs, so we had to go for VGA. The other input options are provided by a kit of converters.

HDMI converter boxVideo format converters

We still need to get the speakers mounted on the wall for a proper cinema experience.

The software for the DLNA was a little awkward, but we got it working in the end. The Pi is running GMediaRenderer, a DLNA renderer for GStreamer. This had to be compiled from source and took some fiddling before it worked how we wanted it. This was worth doing though as we were then able to customise how it looked in the client app. Our logo is on it! We can already cast sound from laptops too, pulseaudio-dlna can cast sound from your linux PC to any DLNA device on the network and it works great.


3D printed coat hooks, wi-fi enabled bike lights and virtual reality

Just an average Wednesday open night down at York Hackspace.

Nick took an old plank from a pallet and with a little elbow grease and some shared knowledge turned it into a fine backing plate to the hold the coat hooks that he designed and printed on the space 3D printer.

Finished Coat Hooks

I took a very cheap hand plane and managed to get a good enough edge on it to let Nick clean up old pallet wood and turn it into quite a fine looking board.

This ended up with a fine mess of wood shavings that Nick was particularly pleased with.
Everybody likes to make some mess.

We had the loan of a PS4 and VR Headset for the night and Nathan spent some time playing at “Job” a virtual world created by the future robots to simulate what it was like to do Job in the 21st century. A lot more fun than it sounds. Everybody was enjoying his attempts to “repair” a car.

Through some more donations of kit we now have a fine looking multimedia setup in the works. It started with a projector that got attached to the ceiling. Then an amplifier and some speakers that is to be mounted on top of a shelving unit ( if you know of any spare shelving please let us know). Then through a convoluted set of connections and boxes we should be able to hook all the ageing kit up to most things. Wire lengths where measured ( in feet, meters, ceiling tiles and string lengths) and we may be able to hook it up next week. It will be useful for doing presentations or just playing tutorials from Youtube. Even the laser painting might be setup at some point.

As any true hackspacer knows things can always be improved with more LEDs and so I added a few more to his bike. Wrapped around the handmade wooden box on the front they currently provide a neat running light setup, red and white back and front then pulsing orange down the side. As they are run from an ESP8266 chip that has built in wifi it seems only a natural next step to add a wifi hotspot to the bike and a web server to control the lights.

More Bike Lights

Many more things where happening. John was having some problems with his new 3D printer but was having fun developing shapes in OpenSCAD. Dave and John where discussing wiring up sheds and sharing the tools to do it. A surprising amount of time spent trying to find something to play music to test the speakers, /dev/urandom, the computers random number generator, only goes so far. I really love the mixture of physical and digital that is happening in the space especially when there is a big group. Oh and we have a new member, Carwyn.

See you all next week.