How to Build an Atari Jaguar S-Video/Composite AV Cable

Official S-Video cables exist for the Atari Jaguar, but they’re frustratingly difficult to find for a reasonable price.  They’re certainly not as bad as GameCube component cables, which can fetch over $100, but there’s really no good reason to pay more than a few bucks for any cable.  There are a few homebrew solutions scattered about, but reliably finding a seller that will quickly get you a cable is still harder than it should be.  What makes this even worse is that the Jaguar only comes with an RF connection by default, and it’s an especially AWFUL RF connection, too!

The solution?  Build your own cable!  If you already have the basic tools on hand (a soldering iron and solder is all you really need, though spare wire and electrical tape are nice to have, too), then all you really need is a few bucks for the right parts and some time.

So, let’s get started.  Here’s what I recommend you have on hand:

Tools:

• A basic, 30ish-watt soldering iron (easily found at Radio Shack)
• Solder, appropriate for high-tech devices (also easily found at Radio Shack)
• Desoldering braid, for fixing mistakes (again, easily found at Radio Shack)
• Black electrical tape, for making temporary connections and insulating wires (you probably already have this laying around)
• Spare electrical wire (optional)

Parts:

• A flat, 24-pin, dual-edge connector, .100 DIP. (This one from DigiKey works perfectly. Other people have used connectors from ribbon cables and blocked or cut off the extra connectors.  That’s janky, but works.)
• A combo S-Video/Audio cable (or S-Video/Audio/Composite, if you want the yellow video connector, too.  I used this one from Monoprice and cut it in half to make two cables.)

That’s it!  Now, let’s get to work.  Get out your Jaguar and take a look at it from the back.  You see the connector on the right?  The wider one labeled A/V?  Yeah, that connector already has all the signals we need running through it.  We just need something that will pass that information on to the TV!  There’s even an RGB signal on there, if you’re so inclined (I’m not).

Here’s a handy pinout reference that shows what information each pin on the conector carries.  Imagine you’re still looking directly at the back of the Jaguar, then you can read what each pin is for.  The connector you bought from DigiKey?  That just provides a nice solder point for each pin.

Now, get out your cable and slice the connectors off of one end (or cut the whole cord in half, if you intend to use it for two cables).  You’ll see a number of wires inside, each responsible for carrying a different signal.  Additionally, each wire will actually have two components: a core signal wire, and a shielding/ground wire.  The ground wire will be wrapped around the core signal wire.

Strip a half-inch to inch of the covering off of each wire. Be careful!  This step was actually harder than I expected. Some of the signal wires are pretty thin and delicate, so I kept breaking them.  In the end, here’s what you should see:

• Audio (Right) – Red + Ground
• Audio (Left) – White + Ground
• S-video (Chroma) – Color varies (mine was white) + Ground
• S-video (Luma) – Color varies (mine was black) + Ground
• (Optional) Composite video – Yellow + Ground

I needed some trial and error in a later step to figure out which wire was Chroma and which was Luma, but there are only two possibilities, so it’s not hard to figure out.

This is really all the information you need.  From here on out, it’s just a matter of soldering the right wire to the right connector pin.  Here’s how they end up connecting, based on the above pinout:

• Right audio: 1B
• Right audio ground: 2B
• Left audio: 1A
• Left audio ground: 2A
• S-video chroma: 8A
• S-video chroma ground: 4A
• S-video luma: 8B
• S-video luma ground: 7B
• (Optional) Composite video: 11B
• (Optional) Composite video ground: 10B

Now, it’s all about technique and just making the connections.  Thankfully, it’s not difficult.  This was only my second soldering project, so anyone can do it!

I found it simplest to solder about two inches of wire to each of the necessary pins on back of the connector.  This was much easier to handle than trying to solder the bulky cable directly.  You can use spare wire if you have it, but I just used a couple inches of stripped wire that I cut out of the cable itself.

Make a connection between the wires in your cable and the wires on the connector by simply twisting the appropriate ones together.  For now, secure each connection with a bit of electrical tape.

Believe it or not, you now have a functioning S-Video cable!  Go test it in your Jaguar.  Make sure to note which side is the top of the connector!  It will fit upside-down, but obviously won’t work like that.  You should see a beautiful, clear picture with stereo sound the moment you turn the system on.  If you don’t see (or hear) that, then make sure your connections are all secure and to the right pins.  Also make sure there are no exposed wires crossing each other. I accidentally mixed a few connections up the first time, so give yourself a little time for trial and error.

Once you have a working cable, go back to your workbench (or dining room table, in my case) and melt some solder on each of the twisted connection points to make them more permanent.  Wrap all the exposed wires in electrical tape to prevent signal crossing.  Finally, wrap the whole thing in even more electrical tape to create a makeshift housing that will protect the wires from general wear and tear.  Don’t be shy with how much tape you use here — the more the better!  Some of the connections are very delicate, so you’ll want to protect them.

The end result?  Well, the device itself is ugly, but the picture it supplies sure is beautiful!