From trash to treasure: Vic20

Seeing as I haven’t posted in a while and probably will not post until next week again due to the current pandemic. I will however make a promise to write about how someone can deal with quarantining while making games that go opposite to that, couch/local multiplayer.

As some of you know that know me know I’m often busy with repairing and modifying old computer, game consoles and handheld. Because of this I will take you on a small trip on refurbishing an Vic20, which i feel is at least a tiny bit relevant to my design choices as explained in a previous article. (The importance of games from the past)

It all started with me buying a Vic20 from a local seller for dirt cheap, the guy claimed it was untested as he didn’t have a power supply and it used to be from his father back in the day who modified it a bit. From the pictures that were included in the listing I could see the computer was heavily discolored and had some weird switches on top, so partially because I was intrigued on what kind of mods where done and partially because I wanted a Vic20 for dirt cheap I bought it.

Well when it came it was worse than I expected. It functioned, kind of… The discoloration was worse than on the the picture, some switches from the mod where rusted and when I tried to move them they broke and there was a huge din-8 plug on the back. To test if it actually worked or not I quickly build an AV cable for it and seeing as this is a later model could use a C64 power supply. But when that was finished I powered it on only to find it gave a barely readable screen but it kind of worked. That was until I tried to test the audio capabilities, as halfway down to copying some code to test that it froze. After another boot it just gave the background color, cyan.

So what I had was a defective, discolored and heavily abused Vic20. Time for a repair.

What I found out when opening the computer was that all except for one switch when to the din port on the back, the reason for it was to switch between different memory banks for the 16k memory expansion cart I got with it. (and to be fair, while 3.5k workable ram already wasn’t that much in 1980, it was almost nothing at the end of the computers life) But at the very least I knew most of those switches couldn’t cause the issues of the computer, as they weren’t actually connected to the Vic. All except for 1 switch, which I suspect was a freezer switch connecting a pin to ground on the cartridge connector. Desolding it and trying it again however didn’t solve any issues.
With the help from people online I did found a method to test the most likely causes, either the BASIC ROM, Kernel or Vic chip. Testing the BASIC ROM was the easiest as using a cartridge on the computer bypasses the chip, but trying that only changed the background color. Then the most likely culprit was the Vic chip, but before that I wanted to rule out some less likely options as I did have some chips in some other computers. So I replaced those chips in the hopes of fixing it, but again no luck. Seeing as I didn’t have an extra Vic or Kernel laying around I ordered an extra Vic, which toke ages to arrive due to the pandemic. But when it finally arrived it fixed the computer. 

The vic chip

So now I have a working computer in a really ugly case.

For people unfamiliar with the Vic20 the case should be near white, not orange/brown-ish.

So first I started with the most time consuming and easiest thing, cleaning the keyboard. This meant removing all keycaps, checking the springs for rust and cleaning the keycaps. I did however find another issue, rusted springs and spacebar bracket. The spacebar bracket was so bad in nearly rusted through. These were later replaced with springs and a bracket from a C64 I had for part, as they use the same style keyboard.

Once the keyboard started to look half decent again I started to focus on the case, first removing all previous mods done to it.

Having holes in a computer case is not ideal however, it looks rather ugly. My plan was to fill the holes with epoxy putty and sand that down, as from previous uses of that stuff I know it sand easier down than plastic. However there was the issue of the hole where the DIN port used to be, as that was to big to let the epoxy sit stable. My solution however was rather simple: melt some straightened paperclips into the plastic. I also removed the labels from the computer pre-emptily. And as you can see on the pictures, the discolored areas look quite bad compared to the area under the label that hasn’t seen sunlight or much oxygen in 40-some years.

This worked quite brilliantly, and after some sanding it looked quite good.

The colors of the epoxy clearly didn’t match the computer and seeing as it’s already heavily discolored it could do with a paint job. I probably would have “RetroBrite” it if it didn’t have the holes, but paint would just do fine. Finding the correct color however was quite hard, even the color I went with isn’t quite right. The Vic20 is a kind of “old plastic white” color that is slightly yellow-ish grey. There aren’t that much spray paint, as far as I found, that had much variant of white but with some searching I found that MTN had colors that came close in their MTN 94 line. MTN however is a graffiti paint company, and I didn’t know how well that would go with plastic. But bought a can anyway, as I really didn’t have another option. It did surprise me however and was quite close to the original color of the Vic20.

The vic20 is slightly more gray

Basing colors of an image online however isn’t ideal, and if I ever redo it I’ll probably go with the color “Bone white” instead of “Ipanema Yellow”, as “Bone white” is slightly more gray and less yellow. On some of my monitors, if I base the color on their site and the sellers, “Ipanema Yellow” either looks way more white or way more yellow than it does in real life depending on the monitor. Having some swatches to choose a color is probably a good idea in the future.

One of the big upsides of using graffiti paint however if that the finish ends up being really rough which feels awful, but ones the lacquer is over that it get the same finish as a new Vic20 or at least the same as my C64 which is in great condition which feels great. So all the wear that make the computer’s plastic feel really smooth from lots of use feels a bit rough again like it was originally. The only thing that might need an update to make it look even more “straight from the factory” is new keycaps as the ones currently used are a bit discolored.

Having said all that, I love the end result:

Vic20, looking like new again!
And working great in all it’s 3.5kb glory!

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