Using s-video gear with Commodore monitors

Commodore and Atari used an early implementation of s-video on their home computers in order to show off their computers’ advanced-for-their-time graphics. Many monitors sold for those computers featured compatibility with this feature, which was called “separated” or “y/c” composite or at the time. JVC called the feature “s-video” when they started using it on their SVHS camcorders starting in 1987, and JVC’s name stuck. Other companies followed suit, and s-video and the mini DIN plug became an industry standard.

Commodore and Atari used a different connector than JVC did, but all it takes to use s-video gear with those old monitors is a cable, which you can make with about $10 worth of parts from Radio Shack.

Pin 1: GND for Luma Pin 2: GND for Chroma Pin 3: Luma Pin 4: Chroma

At right, you’ll see the pinout for an s-video connector, which is available as Radio Shack part# 278-451.

Attach a two-conductor wire (a length of speaker wire will do in a pinch) to pins 2 and 4. The other end of the wire that went to pin 4 connects to the center plug portion of an RCA connector (Radio Shack #274-319 will do). The other end of the wire that went to pin 2 goes to the outer portion of the RCA connector.

For better results, use a length of coax wire. If you use coax, the middle portion of the wire connects to pin 4 of the s-video connector and the center portion of the RCA plug. The outer portion of the wire goes to pin 2 of the s-video connector and the outer portion of the RCA connector.

Mark this plug “chroma.” On Commodore monitors, this jack is red, so use a red RCA connector if you can. Or indicate it with a dab of red paint.

Next, repeat the process above, this time using pins 1 and 3. Pin 3 goes to the center plug portion of a second RCA connector and the other end of the wire from pin 1 goes to the outer connector. Mark this plug “luma.” Use a yellow connector if you can, or indicate it with a dab of yellow paint.

Now you can plug the s-video connector into your DVD player or camera, and plug the RCA plugs into your Commodore monitor. You won’t damage anything if you reverse the plugs accidentally.

If you want, another way to do this is to get a regular s-video cable (I’ve even seen them at Dollar Tree for, you guessed it, a dollar), cut off one end, strip the individual wires, trace them out, and solder the appropriate wires to RCA plugs.

Many monitors made in the 1980s and early 1990s by companies other than Commodore also featured separated composite, so they could be compatible with Commodore and Atari computers. Any 1980s monitor that has RCA jacks labeled “chroma” and “luma” can be used in this fashion.

If you found this post informative or helpful, please share it!
%d bloggers like this: