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 the front of most televisions. Confusingly, this isn’t the key.

Old-school switchbox
An Atari-compatible switchbox like this one will work with a Commodore too

That RCA port sends out a modulated RF signal, not a standard video signal. To use that port, you need a switchbox that connects to your TV antenna. 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. Those switchboxes used to be a standard item at Radio Shack, so you may get lucky there. Or there’s always Ebay.

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, you’re in luck. All you need is a converter. Radio Shack part number 278-276 is equivalent if you want to get it today, but it’s cheaper at Amazon. If you go to Radio Shack, ask for that part number specifically–if you ask for a part to connect a Commodore to a television, don’t expect to get far. Incidentally, that same part also works with Atari consoles (Atari 2600, anyone?) and 8-bit computers like the Atari 400 and 800.

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 it has two plugs, it’ll plug right into the composite video and audio plugs on the front of most modern televisions or VCRs. 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 such with a male connector on one end and two female jacks on the other end (Radio Shack part # 274-881), 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.

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 a Commodore-to-S-video cable.

Way back when, a Commodore monitor gave a much nicer picture than a television, because the switchbox degraded the signal significantly. But a modern TV with standard RCA video connectors gives at least the same quality display that a Commodore monitor did, if not better, since picture tubes have improved in quality in the last 20 years.

I saw a search for this in my logs and I don’t know how many people have ever explained how to do this. In the 1980s it seemed almost obvious, but times have changed.

<a href=”http://www.amazon.com/exec/obidos/ASIN/B000V1O1LM/thesiliconunderg”><img src=”http://images.amazon.com/images/P/B000V1O1LM.01.THUMBZZZ.jpg” alt=”Book Cover” /></a>

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.

Older C-64s had a 5-pin video connector that only provided straight composite.

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.

(Why am I posting about 20-year-old 8-bit computers? Somebody asked, that’s why. Besides, 8-bits were/still are a lot more fun than a PC/XT.)