Tag Archives: video cables

How to connect a Commodore 64 to a television

It is less than obvious how to connect a Commodore 64 to a modern television, especially if your C-64 didn’t come with the cables or the manual.

There are, as it turns out, several ways to do it.The C-64 and 128 have an RCA jack on the back that matches the RCA jacks on most televisions, whether LCD or CRT. Confusingly, this isn’t the key.

Old-school switchbox
An Atari-compatible switchbox like this one will work with a Commodore too, but it probably doesn’t have the right connector for most newer TVs

That RCA port sends out a modulated RF signal, not a standard video signal. Originally that port was intended to connect to a switchbox that connected to a two-wire type of TV antenna connector that was common in the 1980s. Commodore used the same switchbox as Atari, so you may have one laying around or be able to find one in a box of ancient computer and videogame cables.

RCA/F connector adapter
This cheap part will happily connect a Commodore to most televisions today

If your TV has a round antenna connector rather than a two-wire connector–a fairly safe bet–you’re in luck. You need an RCA video cable along with a converter, which you can get from Radio ShackAmazon or Ebay. Ebay is likely to be the cheapest option, but be careful on Ebay to get something that looks like the picture to the left–it’s easy to accidentally buy the opposite. Incidentally, that same part also works with Atari consoles (Atari 2600, anyone?) and 8-bit computers like the Atari 400 and 800.

Using either the switchbox or the adapter, the Commodore video signal shows up on channel 3 or 4 on your TV. There is a sliding switch on the back of the machine to choose which channel.

But that’s not your only option, and today, it’s not even the best option. Near that plug, you’ll find a round DIN-type plug. On most C-64s and the C-128, it has 8 pins. On the very early versions of the C64, it has 5 pins.

Commodore video cables have the proper DIN plug on one end and RCA plugs on the other. If your cable has two plugs, it’ll plug right into the composite video and audio plugs on most recent or recent-ish TVs. The color codes should even match. If the video cable has three plugs, what you have is actually separated composite, an early implementation of S-Video. No problem; get a Y-adapter with a male connector on one end and two female jacks on the other end, plug the red and yellow RCA plugs from the Commodore cable into that, and then plug the adapter into the video plug on your TV. Or, if your TV has an S-video connector, I cover that in more detail here.

What if you can’t find a Commodore video cable? If you’re handy with a soldering iron, you can make your own cable with parts from Radio Shack. You’ll need a 5-pin DIN plug, two male RCA plugs, and two lengths of speaker wire. Shielded cable like RGU-58 would be better, but isn’t totally necessary.

Here’s the pinout on the Commodore video port.

    no connection -----8           7-----no connection
                             6---------chroma out
       audio out -----3             1----- luminance (B & W signal)

          audio in -----5         4----- composite video out
                             2----- ground

Solder one wire from each of your lengths of speaker cable to pin 2 on the DIN plug. Solder the other end of each wire to the outside post of each RCA connector. Solder the other wire of one cable to pin 4 and to the RCA plug, and label that wire pair “video.” Solder the remaining wire to pin 3 and to the other RCA plug, and label that wire pair “audio.”

If you have a S-Video plug on your TV and you want a higher-quality display, I have instructions for connecting via S-video.

Way back when, a Commodore monitor gave a much nicer picture than a television, because the switchbox degraded the signal significantly. But a modern-ish TV with standard RCA video connectors gives at least the same quality display that a Commodore monitor did, if not better, since picture tubes improved in quality during the 1990s. Display quality on LCDs varies, because LCD TVs tend to be a bit picky about composite signals and most consumers are more concerned about digital inputs than about the old analog inputs these days. As a general rule, the older the LCD TV, the better it’s likely to work as a Commodore display.

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How to connect a C-64 to a modern TV’s S-Video input

In the 1980s, a computer monitor offered a clearer picture than a TV by eliminating the need to modulate/demodulate the video signal, which caused degradation. But in 2003, it’s next to impossible to find affordable composite monitors for 20-year-old computers, and when you can find them, their size pales in comparison to a $99 TV. Why bother with a really old, curvy 13″ monitor when you can retro-compute in luxury on a flat 19″ TV?
Fortunately, if a TV offers composite jacks, you can connect a computer directly to it. No tricks involved–you connect it just like you would a VCR.

But Commodore 8-bit computers (the 64, 128, and Plus/4) used a trick to get a clearer picture: They seperated the chroma and luma signals. This is exactly what S-Video does today. So it’s possible to get a better-still picture out of a Commodore, if your TV has S-Video jacks.

Note: Older C-64s had a 5-pin video connector that only provided straight composite. Those connect just like a VIC-20. Don’t modify it to provide S-Video, the machine is worth much more unmodified.

By far the easiest way to connect a Commodore to S-Video is to buy a cable. They’re common on Ebay for about $20.

You can also make your own if you want. Making video cables isn’t difficult, assuming you have decent soldering skills. Usual disclaimers apply: I make no guarantee as to the accuracy of this information. I believe my sources are accurate but I don’t have a working Commodore to try this on right now. Connecting the cables wrong should only result in lots of noise and lots of snow on your TV screen, but if you somehow mess up your computer, it’s not my responsibility.

Later C-64s, C-128s and Plus/4s used an 8-pin DIN connector. S-Video uses a 4-pin mini-DIN connector, the same connector used on Macintosh keyboards from about 1986-1997.

If you already have a Commodore video cable, you can easily make an adapter. Get a 4-pin mini-DIN connector and two female RCA plugs, red and yellow. Connect S-Video pin 3 to the center of the yellow plug. Connect pin 2 to the outside of the yellow plug. Connect pin 4 to the center of the red plug, and pin 1 to the outside of the red plug.

If you don’t have a cable but can locate the appropriate connectors, you can make a cable like so:

   Commodore              S-Video

        2                  4   3
     4     5              2     1
   1    8    3
     6     7

  (solder side)        (solder side)

Commodore pin 1 goes to S-Video pin 3 (luma)
Commodore pin 6 goes to S-Video pin 4 (chroma)
Commodore pin 2 goes to S-Video pins 1 and 2 (ground)

Commodore pin 3 goes to the center of an RCA connector for audio. Connect the outside of the RCA connector to Commodore pin 2.

To make a straight composite cable for a C-64 or VIC-20 (the VIC had a 5-pin plug, and so did early 64s–the later plug is backwards compatible with this 5-pin plug), connect Commodore pin 4 to the center of a yellow male RCA plug. Connect Commodore pin 2 to the outside of the yellow plug. Connect Commodore pin 3 to the center of a white RCA male plug, and Commodore pin 2 to the outside of the white plug.