Watch on YouTube: https://www.youtube.com/watch?v=GShDIkdpq58
Atari Video Music History, S-Video Mod, UK 230V Power Mod & Restoration
Introduction
The Atari C-240 Video Music was a rather weird music visualiser released in 1977. Join me as I share the story behind how and why the gaming and home computing giant decided to try to get into the world of audiophile hi-fi separates, and fix and restore mine with some brand new walnut side panels, an s-video output mod, and an internal 230V PSU mod so it can run happily on UK power.
That’s right, I’m doing vintage hifi repair videos now!
Script
Hi everyone, Rees here, and in this episode of ctrl-alt-rees I’m going to be taking a look at this - my restored and upgraded Atari Video Music - an interesting -well, downright weird - piece of hi-fi equipment which was released by Atari in 1977.
That’s right - this isn’t actually a computer or a games console as you might expect from Atari, but a rather stylish component for a hifi separates system.
So I’m going to be telling a little bit about the - rather unusual - story of how the Video Music came to be, I’m going to show you inside and explain how it works, and also show off some of my upgrades, including real walnut replacement side panels, an internal 230V power mod and - in what I believe to be a world first - an s-video output mod that allows me to get the best possible video quality from this thing.
Photosensitive epilepsy warning. Parts of this video include flashing and strobing effects.
In the 1970s, hippie counterculture ruled at Atari, in stark contrast to their stuffy corporate Silicon Valley neighbours like IBM and Intel, and it was this free spirited mindset that ended up attracting fresh faced young engineers looking to expand their minds and make their mark on the world.
Atari was infamous for its so-called “company retreats” - otherwise known as weekend-long drink and drug fueled hot tub parties - which spawned many of their innovative early game and hardware concepts.
It was during one of these retreats that the Video Music concept came about - a box that could be connected to a hi-fi amplifier and a TV, and use a custom integrated circuit to generate brightly coloured patterns on the screen synchronised to the music. In keeping with the aesthetic of the time, its high tech design would feature a combination of brushed metal, black vinyl, and brown and orange buttons.
Oh, and wood of course. Because, well, 70s.
Codenamed “Project Mood”, a prototype was assembled by Atari engineer Bob Brown, who had previously been responsible for the home versions of Pong. Thanks to the company’s pre-existing relationship with department store giant Sears, who had been selling the TV consoles under their own Tele-Games brand since 1975, Atari potentially had access to the perfect retail outlet - if only they could persuade them to stock it.
“Bob Brown had designed Video Music, our weirdest product ever. Hook it up to your stereo and TV at the same time, and the sound triggered some pretty psychedelic visuals. The Sears guys took one look and asked what we’d been smoking when we did that. Naturally, one of our techs lit up a joint and showed them.”
Despite the rather informal introduction, Sears did indeed take Atari up on their idea and put the Video Music up for sale in their stores in late 1977 for $169.95. Historical sales figures from this period are hard to come by, but as it was on sale for less than a year and is something of a rarity today, it’s probably safe to class this one as a commercial failure.
At the time of the Video Music’s development during 1976 and 77, Brown was also working on this - the VCS - with which the Video Music shares some electrical similarities, particularly in the way that the video output is generated.
And much like my Heavy Sixer here, my Video Music was in need of some sympathetic restoration, as well as a few quality of life improvements to make it as convenient as possible to use here in the UK and to hook up to modern equipment.
For a start, it originally output an NTSC RF video signal, the same technology used for US TV broadcasts of the time. Unfortunately there weren’t many TVs this side of the pond that could actually tune in to it, and even in its homeland those old TVs are rapidly dying out.
Adding s-video would open up a lot of options, not only including CRTs as originally intended - provided they support NTSC input of course - but also modern upscalers such as the RetroTink here, for display on an HDMI TV or a projector.
The other thing I needed to address was the power supply - of course the one that came with this was a US 120V unit, which had been badly repaired by a previous owner, so I came up with a very simple internal 230V solution to replace this.
Taking a look around the outside of the unit when I first got my hands on it, I could finally truly appreciate that 1970s design aesthetic, with lots of brushed steel, and those lovely orange and brown buttons. Of course I’ll show you what they all do later on when it’s up and running.
There’s also the vinyl effect top, and those walnut-effect melamine side panels, which are looking very much worse for wear after 40+ years.
On the back we have the audio inputs. These are standard phono or RCA connectors, and this doesn’t have any kind of outputs, so splitters are required unless plugging into a tape monitor or similar output from an amplifier. Inputs don’t need to be line level by the way - it’s very tolerant and has gain controls on the front to dial in the sensitivity.
Here we have that compact 120V external power supply.
Oh, and finally, here’s where the RF TV cable originally connected. It seems a previous owner cut this off for some reason, but still included it with my unit - not that I’m going to be reinstating it anyway.
So to get our first glimpse inside, we just need to remove these 3 bolts that attach the lid.
As they’re not standard screws, I’m not sure I have the correct tool for this, so I guess I’ll have to improvise.
Wait, no. It turns out I do have one after all…
Now the lid is off, we can have a poke around inside. First up, we have 5 potentiometers connected by a ribbon cable, and underneath those, some lovely chunky switches. In the power supply section there are 2 rather substantial axial capacitors, which, it would appear from the schematic, are actually decoupling caps. I’m not sure why they need to be so big.
Here we have another potentiometer, which is used to fine tune the clock frequency, and the IC where the actual magic happens. This custom chip, designed in-house by Atari and manufactured by American Microsystems, used NMOS or N-Type Metal Oxide Semiconductor logic, an old chip technology that has long been superseded due to its high power consumption and susceptibility to interference.
It’s also a very strange one in that it runs on 3 different voltages - +5V, +12V and -5V, [check] as opposed to modern all digital ICs which on the whole are designed around TTL or Transistor-Transistor Logic at 3.3 or 5V.
Unfortunately the actual inner workings of this chip don’t seem to have been reverse engineered and therefore modern replacements don’t seem to be available, at least from what I’ve been able to dig up, so I’d rather not blow it up if I can help it.
Atari helpfully included 4 very big and obvious links that carry the luma, chroma and sync signals from here to the RF modulator, so this is where I’ll tap in for the s-video mod.
So now it’s time to - carefully - tear this thing down.
Removing the buttons without damaging them is a fiddly business, and was by far the longest part of the teardown. The buttons clip over the ends of the switches, and as the 40-year-old plastic is likely to be very brittle I had to proceed with caution.
I eventually came up with a method that involved gently levering the clip apart while pulling the button, and I’m pleased to report that all 13 of them survived completely undamaged.
I’ve seen plenty of these for sale over the years with missing or broken buttons, so I’m very happy with that result.
As you can see, the buttons were absolutely filthy, so I gave them a good scrub in some soapy water along with some of the other parts.
Now it’s just a case of removing the motherboard and front panel, and then I could finally remove those original MFC side panels, which just attach using self tapping Philips screws.
These panels are definitely beyond help, as all of the edging is coming off - and one of them looks like it’s been on the receiving end of quite a big impact at some point.
I decided to ask my Twitter followers whether replacing these with real walnut would be appropriate, and the response was actually very positive - so I decided it must at least be worth a try.
Of course, like all of my other mods, I’ve stored the original parts away safely so it can be put back at a later date should it not work out or I change my mind.
I’d never really done any kind of woodwork like this before, so I bought some walnut offcuts online which had been trimmed down to the correct size, then I transferred all of the holes over, which I measured and drilled.
After test fitting the sides to make sure the holes were in the right place, I gave them a quick once over with some fine grit sandpaper using a sanding block to keep it flat.
I decided to use this Ronseal walnut varnish, and although it was purple when I first applied it - which, not gonna lie, was kind of concerning - it actually dried OK and the colour and finish ended up being very close to the original fake walnut, so that’s a great result.
With the varnish drying in my workshop, I turned my attention to actually getting a video signal out of this thing.
When I first got my hands on it, I cobbled together a proof of concept circuit based on a schematic I found on Twitter, posted by a user called Paul Rickards a few years back.
Of course, with the presence of separate luma and chroma signals, the temptation was very strong to keep those separate rather than combining them into a composite output, so I gave it a go and my initial tests were very promising indeed.
If you’re following along at home, this is the point where I should warn you that this circuit isn’t perfect, and there’s definitely room for improvement. Yes, it works very well, and with a small modification I’ll go into in a minute, I managed to improve the picture quality even further. But as Paul warned in his original Twitter thread, the output levels are kind of all over the place, so there is potentially a risk of damaging the Video Music as well as whatever you hook it up to - so don’t sue me, or Paul for that matter, if that happens.
I’d actually embraced my inner artist on this one and freeform soldered it rather than prototyping it on a breadboard like I usually would, so with a known working solution as a starting point I decided to transfer the s-video circuit to perfboard.
Once the circuit was assembled, I fitted the socket into the hole where the RF cable originally was. It involved drilling two small holes for the screws which I have to admit is something I’m not keen on, but in this case it did give a very tidy and stock looking end result.
Then I stuck the board to the back panel using some double sided adhesive foam pads.
With the s-video mod installed, I needed to tap into those metal links to pick up the video signals. In my prototype I used crocodile clips, but I came up with the idea of fitting some pins and using Dupont connectors which I think is very much in the spirit of how everything else connects in here, and will allow me to swap the board out easily later if I refine the circuit.
As these have been here for over 40 years at this point, I applied some brand new solder and a liberal coating of flux before desoldering to minimise the risk of damage to the solder pads.
Of course, as always, the metal links are safely stored away alongside the other removed parts in case I want to return this to stock later on.
I then cut the individual pins from a pin header strip and used some Kapton tape to hold them in place for soldering.
Even though this is marketed as “no clean” flux, I still like to remove any residue with some IPA.
Incidentally, I tested the Video Music off camera at this point, and it didn’t seem to be working. Panicking that I’d broken something - not an unusual occurrence for this channel - I reinstated the original links on the underside of the motherboard which thankfully brought it back to life. As the picture I was getting was surprisingly clean even with the RF circuitry reconnected, I decided I may as well leave them in. This also has the benefit of making it easy to reinstate the RF output later on if I ever feel the need.
That said, in line with Paul Rickard’s findings with his composite mod, I found that the colours were pretty weak compared to some footage of the original RF output that I’d seen online. After some probing, I decided this could be down to the peak to peak voltage on the luma pin, which also carries the sync signal. I managed to bring this down a bit by adding a 100ohm pulldown resistor, which not only improved the contrast of the colours but also the stability of the picture. Success!
Up to this point I’d been using the Video Music with this 110V stepdown converter, I’ve had this for about 15 years now and it’s served me very well with all sorts of import stuff from the US and Japan. But looking at the state of that original PSU, I knew I needed something a bit safer and more modern, so why not take the opportunity to convert it to UK mains voltage at the same time?
The original external unit has 3 wires coming out of it - it’s a centre-tapped 16.6V transformer, meaning that the Video Music needs AC power.
I managed to track down an 18V equivalent - the closest I could find - and installed it internally with a hardwired power cable with a UK plug. I did consider fitting an IEC socket, but that would’ve involved cutting a hole in the original metal - something I like to avoid where I can.
Here’s the original PSU with it’s rather dodgy looking repairs, and as you can see, I’ve removed the original connector at the motherboard end so I can reuse it with the new transformer.
…and here’s the prototype I came up with just to prove that the concept works. Yeah, never mind that bit, it’s just what I had to hand.
The transformer is nice and compact and also panel mountable so I should be able to install it inside the Video Music, although it will probably involve drilling a couple of holes. But hey, if it modernises this thing and makes it safe and a bit more useful, I think that’s a small price to pay.
This works great, so let’s get it installed!
I found a convenient spot right next to where the original power cable came through, and as it happens, I can even reuse one of the original holes for the side panel screws, so I only need to drill the one. This also means that the modification won’t be visible from the outside at all, which is fantastic.
There’s just about enough room to manoeuvre the board back in with that transformer in place - I probably should’ve checked the clearance but hey, I’ll hopefully only have to do this once.
I decided to hardwire the new power cable, just like the original. Of course this time it’ll have a UK 3-pin plug. I even reused the original plastic grommet or cable gland whatchamacallit which locks the cable into place and prevents it being pulled out.
So just a tidy up to make sure those wires are tucked away neatly and away from any video or audio circuitry where they might cause interference, a quick test to confirm that it’s all still working OK - and it’s finally time to put everything back together.
…and that brings us to today, and I have to say, I’m really pleased with how this all came together. There’s still a bit of a deep scratch on the front panel as well as some tarnishing to the metal, and I suppose I could use some metal polish to try to clean that up but I really don’t want to risk damaging any of the original printed text and, to be fair, it’s not like I’m trying to pretend that this is brand new so I think it does add some character and I’ll probably leave it as is.
Anyway, I know you’ve all been waiting for a proper demo of the various functions and I’ve managed to track down the manual, so lets run through all of the knobs and buttons and see what they actually do.
And I know I’ll inevitably have some hardcore audiophiles in the audience, so I spared no expense with the setup here, I’m sure you’ll agree. I’ll be using this record from top chiptune legend Hoffman who has given me permission to use his tracks in this video, so hopefully there’s no risk of a copyright strike - and there’s a link to buy this down in the description.
So there we have it, another successful restoration and upgrade, I hope you’ll agree. I should also point out that I built an open source clone of the Video Music in a previous video, it’s called the Pixelmusic 3000 and is based around a Parallax microcontroller and was a lot of fun to put together, so check out the link to that video up above and down in the description if you’re interested.
Speaking of electronics projects and old computer stuff, if that’s the kind of thing that tickles your fancy please do consider subscribing to the channel and don’t forget to give this video a thumbs up if you enjoyed it - it really helps me out.
Thanks as always to my patrons and channel members whose names are up on the screen as I speak - you help me to fund these projects and keep the ball rolling and if you’d like to join them you can also find the details for that down in the description.
So finally, all that’s left is to thank you very much for watching, and I hope to see you again soon.
Original Video Links
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Relevant Links:
Paul Rickards Twitter Thread (Composite Mod): https://twitter.com/paulrickards/status/901505157074210817
Atari Video Music schematic: https://ctrl-alt-rees.com/downloads/atarivideomusic/Atari_C240_Video_Music_Schematic.png
Atari Video Music Manual: https://ctrl-alt-rees.com/downloads/atarivideomusic/Atari_C240_Video_Music_Manual.pdf
Atari Video Music patent: https://patents.google.com/patent/US4081829
Pixelmusic 3000 Open Source Video Music Clone: https://www.youtube.com/watch?v=53qIO64FHdg
Big thanks to John from Amigos Retro Gaming for the voice acting contribution and for taking the very weird quote I sent over in his stride! https://www.youtube.com/AmigosRetroGaming
Also thanks to h0ffman for allowing me to use his track “Hot Dots” to demo: https://soundcloud.com/h0ffman
You can buy h0ffman’s vinyl album “The Cave Sessions” from the RMC Retro store: https://rmcretro.store/h0ffman-the-cave-sessions-double-vinyl-record/
If you liked this video please consider subscribing to ctrl.alt.rees on YouTube!
