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Commodore 1702


Everyone knows the Commodore 64, even if they've never used one. Slightly less well known but far more useful in this day and age is the Commodore 1702 video monitor.

These little guys were introduced around 1982 as an alternative to using a crappy TV for a monitor on your Commodore 64. And what a difference it made! The 1702 gave you a beautiful crisp image and handy front A/V inputs in a tiny stackable package. They even had a pair of RCA jacks on the back for separate Chroma and Luma input. These days we'd call that s-video, but at the time they just called it Commodore video. Either way you got a far superior picture than any composite monitor or TV could manage. It's no wonder people found uses for them that Commodore had never intended, such as in TV studios or security rooms. And even 28 years later most of them are still going strong.

Now of course we have LCD TVs that'll outshine it in brightness and colour while being sharper than its designers could dream of, but the sheer versatility, ruggedness and thrift store availability of these things means they're still seeing use. In fact, there's one area where these little beauties can outperform a modern LCD TV.

Scaling.

LCD, Plasma and OLED screens are all fixed resolution devices. Their screens are made up of hundreds of thousands of tiny squares, each of which can change colour to become part of a larger image. For the image to look sharp and clear, it needs to be the same resolution as the screen, meaning it has to be made up of the same number of tiny squares. So when you give it an image which is too big or too small (Say watching an old VHS tape on a modern 1080p TV, or trying to watch a 1080p blu-ray on a 720p TV,) the image has to be stretched or squished to fit within that fixed grid of squares. The results are seldom pretty. Text especially tends to become hard to read, and everything gets a bit fuzzy.

The old fashioned Cathode Ray Tube on the other hand functions as more of a projector. A "Light gun" at the back of the 'tube hurls a pattern of electrons forward, causing little specs of phosphorus on the inside of the glass to light up and create the image. This gives it a great deal of flexibility when it comes to input resolution. So long as the resolution is lower than the number of openings in the front of the glass (Called the mask,) you'll end up with a nice looking picture. And even when the resolution exceeds that limit the results are usually okay, the image just loses fine detail. This makes a CRT monitor ideal for playing old games on, watching home movies or any number of videos which would become chunky and awful on a fancy new high definition LCD TV. And with the price so low, they're great for giving to the kids.

There's a slight snag though. Remember what I said about the separate Chroma and Luma connectors? At the time it was an amazing thing to see, but these days you won't find anything that outputs s-video via two RCA cables. I've seen people make adapters from the standard 4 pin s-video plug to 2 RCA connectors, but I think I have a better solution.

Bam! S-video input. All it takes is a "borrowed" s-video connector, 4 wires, some glue and a way to drill the hole.

It's as simple on the inside as it is on the outside. Just 4 wires from the jack to the Chroma and the Luma connectors brings the 1702 one step closer to the modern age.

How does it work? Like a dream. The picture is even sharper and clearer than before. I've got 3 of these monitors at the moment and they've all been modified like this. It's so easy and the improvement so large that there's no reason not to.

If there's any interest I'll record a video walkthrough the next time I modify one of these.