Watch on YouTube: https://www.youtube.com/watch?v=53qIO64FHdg
Atari Video Music Open Source Clone - The Pixelmusic 3000!
Introduction
Sponsored by JLCPCB: $2 for 1-4 Layer PCBs, sign up to get $18 in new user coupons: https://jlcpcb.com/DYE
The Atari Video Music was Atari’s brief foray into the world of hi-fi and was released in 1977. But these units are getting very hard to come by now… So why not build your own? In this video, I do just that by putting together a Pixelmusic 3000, a project by Uncommon Projects and Make Magazine from 2012.
Script
Hey everyone, Rees here, and welcome back to ctrl-alt-rees. Now, in a previous episode I started restoring a Video Music, Atari’s trippy music visualiser from 1977. And yes, it was a while ago, but I finally have all the bits I need and I promise it will be finished very soon.
But in the meantime I wanted to introduce you to this - a modern open source recreation that was designed by a group called Uncommon Projects and published in Make Magazine back in 2012.
In this video, with some help from this project’s sponsor JLCPCB, which I’ll talk about a little bit about later on, I’m going to show you how this all works, how to put one of these together, and a few enhancements I came up with on my own like this snazzy retro styled housing.
So first, just a little bit about this project. The Atari Video Music was arcade industry giant Atari’s ill-fated venture into the world of hifi, and was released in 1977, the same year as their iconic 2600 console. In fact it shared a few elements in common with that console, including lead engineer Bob Brown, who’d previously been responsible for the home version of Pong.
But if you want to know more about the story behind the Video Music and how it all works, I highly urge you to check out my original video on the subject, which is linked down in the description and at the end of this video.
So, what is the Pixelmusic 3000 all about? Well, I stumbled across this on Make Magazine’s website, and unfortunately, being from nearly 10 years ago, a lot of the links were broken. I went hunting for the original creators - a group calling themselves Uncommon Projects - but their website was long gone too.
I actually had a bit of a job hunting down proper documentation and code for this, a lot of it involving my old friend The Internet Archive, but I’ve rounded up everything I can and put it up on my website, so consider this my contribution to the very limited documentation that’s out there, and hopefully now it won’t be lost to the ever-present scourge of bit rot.
Well - until my website inevitably disappears as well.
The original project was built on perfboard, with a breadboard prototype of course, and built around the Parallax Propeller, an older but very capable 32-bit 8-core RISC microcontroller chip introduced in 2006.
The Propeller supports programming in Assembly, C and C++, and its own proprietary languages BlocklyProp and Spin, the latter of which was used for this project.
On the hardware side, the Pixelmusic 3000 uses a 24LC256 256K serial EEPROM to store the program code and an MCP3208 analog-to-digital converter to actually get the music into the thing, and apart from that, just a small handful of discrete components including a 5MHz crystal to clock everything.
To be honest, it was so simple that I actually skipped the whole prototyping stage and just drew up the PCB in KiCAD and sent it off for fabrication - and you know what that means. It’s sponsor time!
So, as I mentioned at the beginning of this video, I had these boards fabricated by JLCPCB, a service I’ve used many times in the past on various projects, and I’ve always been genuinely pleased with their customer service, the turnaround time and of course the quality of the end product.
So when they contacted me offering to sponsor this project of course I didn’t hesitate to jump on board.
So what is JLCPCB? Well, they’re an online PCB fabrication service, obviously. In addition to the 2 layer board I have here, they also offer 4 and 6 layer boards, and if your requirement is for SMT stuff, which is all a bit too advanced for me I have to admit, they can even provide the stencils, generated from your designs.
Not only that, but they can manufacture it all for you too!
So in my case, I drew up the schematic in KiCAD, based on the original designs, generated the basic PCB, and routed all of the tracks in the usual way. Of course your workflow may be different, and you can use any PCB design software that’s capable of exporting industry standard Gerber files and drilling templates as required.
If you want to know the cost upfront, you don’t even need to upload your files first - provided you know the size of the end product and specific PCB requirements you can plug all of that into JLCPCB’s website and their instant quote tool will give you a price straight away.
Then it’s just a case of uploading the Gerbers, tweaking the options including funky colours like the blue I’m using here, and letting their helpful approval team run a few checks to make sure there are no serious issues. Then you can sit back and relax while their state of the art production facility manufactures your project to your exact specifications - but don’t put your feet up for too long, as in my case the boards were with me within a week.
1-4 layer PCBs start at just $2 and there’s a link down in the description to get $18 in new user coupons, so if you’re thinking of building one of these using the files available on my website - also linked below - or indeed anything else PCB-based for that matter, go and check them out!
And here is the end product - a lovely, blue, 2 layer PCB. Now, I didn’t opt for any of JLCPCB’s assembly options - that wouldn’t make for a very interesting video after all, so I’m going to assemble this myself the old fashioned way.
I bought all of the parts from RS Components - apart from the Propeller which I found on ebay - but to be honest there’s nothing too exotic here and it should all be available from your friendly local electronic component stockist. The complete bill of materials is available on my website which is linked down below in the description, but I’ve also put them up on screen here for your perusal.
So, in no particular order, I’ll start soldering things up, including the 5MHz timing crystal and a potentiometer, which is used to adjust the sensitivity, depending on the volume of the input.
Next up I’ll add the 3.3V regulator, which is an LM2937. This will accept an input voltage all the way up to 26V, but it’ll generate a lot of heat in that case, so the original designers recommend a 6V PSU, and who am I to argue?
To get some power into this regulator we’ll need a barrel jack - this one actually wasn’t quite the right footprint for the one I picked in KiCAD’s library, but I managed to bend the rear negative pin back slightly to get it to fit securely into the board.
Now I’ll add these 2 electrolytic capacitors, which are decoupling - or bypass - capacitors on the voltage regulator to make sure those incoming volts are lovely and smooth.
This side of the board is getting there now, so I’ll add the two resistors, the 8-pin socket for the EEPROM, and the power LED before moving on to the other side. To be honest, I’m pretty much just assembling this in the order that the parts are coming out of the box, there’s no right or wrong way to do it.
Next up we need a 40 pin socket for our Propeller microcontroller. These are always fun to solder. I like to do the first couple of corners sideways before turning the board over to finish the rest.
Nearly there! Now we add the 16-pin socket for the analog to digital converter. This component takes the incoming analog audio signal and turns it into a bunch of 1s and zeros that the Propeller can understand.
Then there are a couple of pin headers, and the last few resistors - but I forgot to hit record for that bit for some reason, so here’s a shot of the finished thing. I’m pretty sure you’ve all seen more than enough to judge my soldering abilities by now anyway.
So now it’s a case of programming the thing, and there are a couple of ways to do that depending on how familiar you are with the Propeller ecosystem, but this circuit is designed to use Parallax’s own Prop Plug connector, which is basically a USB to serial adapter. As I’m new to all this microcontroller stuff I decided to play it safe and just go with this as it’s the hassle-free option.
The Prop Plug plugs into a dedicated 4-pin header on the PCB, and then it’s just a case of opening the Spin project in PropellerIDE. Here we can see the code on the right, and the dependencies on the left, including external libraries to handle the TV output, graphics drawing routines and the input from the MCP3208 analog-to-digital converter.
At the top we can check that the Prop Plug is being successfully detected on COM3, and then to program the EEPROM just click the green write button, or press F11. It’s a fairly small program so it flashes past pretty quickly, but you’ll know soon enough if everything has been successful because it’s time to test!
I wired up a very quick connector using a 4 pin DuPont socket and a TRRS connector, which connects to a standard Raspberry Pi composite cable. There’s actually a little shortcut we can take here as the inputs and output are connected directly to each other - it’s a straight pass through - so for testing we can get away with just the one cable for audio input and video output.
…and it works!
Unfortunately due to my choice of copyrighted music, that’s all I can show you.
So it’s about time I put together an enclosure for this, and I found this rather nice one on ebay. I was surprised at how sturdy it was for the price, and although it’s a little on the large side for my needs, I don’t think massive boxes with barely anything inside are completely unprecedented, particularly in the world of hifi.
It does have some mysterious dents in the plastic despite being brand new and well packaged, but I guess that’s always the way with this cheap Chinese stuff and I’ll just make sure the better side is at the front.
So first up, I need to deal with the fact that it’s completely the wrong colour. So I sprayed the various plastic parts black, and although it was pretty dark outside I’m really pleased with the way it came out.
After drilling holes for the buttons, power, input and output sockets and LED, I covered the whole thing in this rather tasteful woodgrain vinyl, incidentally the same stuff I used for my little JVC PVM.
Then it was just a case of fitting the board inside the enclosure with some self adhesive PCB standoffs and wiring everything up.
Of course, it doesn’t have the front panel knobs and buttons like the original, and that’s definitely something that could be added with some future improvements to the hardware and software as the Propellor has plenty of inputs.
I didn’t have any panel mount power sockets in my parts box, so I’ve decided to go with a trailing cable, although to be fair this is similar to the original Video Music so it’s not all bad. It could do with some strain relief which I’ll sort out later but I’ll just be gentle with it for now.
And so that brings us to today - and I have to say I’m really pleased with how this turned out. And I think the least I can do is a proper demo.
Now, I know I’ll have some hardcore audiophiles in the audience and so I spared no expense with the record player, I’m sure you’ll agree.
This time h0ffman and RMC Retro will be providing the audio so hopefully there’s no risk of a copyright strike, and I’ll be using the same track that I used to demo the original Video Music so we can also have a look at them side by side and see how they compare.
Very cool, I hope you’ll agree. All the info you need to build your own Pixelmusic 3000 is on the link in the description. I’d like to thank Make Magazine and Uncommon Projects for originally putting this out there, and hopefully with this video and the information I’ve gathered together on my website we might even see something of a mini revival, which would be very cool to see.
So if you enjoyed this project don’t forget to give it a thumbs up and maybe share it with your friends, it’s all very much appreciated and helps me to grow the channel - and if you’d like to see more electronics projects like this as well as my vintage computer restorations and retro gaming stuff - please do consider subscribing.
So all that’s left is to thank you very much for watching, and I’ll hopefully see you again soon.
Original Video Links
Relevant Links:
Atari Video Music Restoration Part 1: https://www.youtube.com/watch?v=4SDXysfnMRk
Documentation, KiCAD Files, Gerbers, BOM: https://ctrl-alt-rees.com/2020-11-26-pixelmusic-3000-modern-atari-video-music-clone-parallax.html
Buy H0ffman “The Cave Sessions” LP: https://rmcretro.store/h0ffman-the-cave-sessions-double-vinyl-record/
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