VIC-20: It’s Alive!

Ah, the things middle aged men do to recapture their youth. Some buy a sports car and date women half their age, while others buy old stuff and play with it… I, with my Commodore VIC-20, would be the latter. Don’t get me wrong, I would buy a Datsun 240Z in heartbeat (because it’s the coolest looking car since, like, ever!) if I thought my wife wouldn’t have my head keep on rolling after 240Z stopped in the driveway. I digress…

My VIC-20 did not come with any extras, no cords, no adapters, no drives, nuthin! Meh, what can you expect for $20? I certainly did not expect that it came with a manual, so kudos to the previous owner for that. All I had was the knowledge that the machine was in good shape and that it did work the last time it was tested, whenever that was. That was fine, because I primarily purchased it so that it could grace my desk with its retrotastic presence. However, I did want to see if it worked and if it did, I would eventually get some stuff to use with it (ultimately, I would like to get a Commodore 128 to retrocompute upon).

The first thing I needed to do was scour my house and find two “wall wart” power adapters that could provide the (5VDC/1.5A) and (9VAC/1A), as they can be combined to provide the power that the VIC20 requires. This is by far the easiest and cheapest way to power a VIC20 or C64 if you have a fair amount of tech junk kicking around. I had all but given up on scrounging the 5V when I decided to take a closer look at the broken adapter (kids broke the USB connection) for my Blackberry Playbook, because my old eyes really were able to make out if it was 1.0A or 1.8A written on in super tiny letters and I none of my other adapters have enough amperage. Sure enough, it was 1.8A. Combined with the 9V supply from one of old Lynksys routers, I had the power!

As part of my initial research, I looked at purchasing a 7 pin DIN connector for power plug, but I couldn’t find any locally and the ones I found online tended to have crazy shipping prices. $2 for the item with $20 for shipping does not make any sense, Mouser.com… My experience with buying very inexpensive, yet high quality components from China on Ebay has been great, apart from the whole “slow boat from China” aspect of the shipping, so I will probably go that route in the long term. In the mean time, decided to test the VIC-20 using some hand built DIN pins.

he following is a series of pictures and steps demonstrating how I crafted a plug for the Linkysys adapter (rather than wreaking it), the pins for the power and video cables, and how I attached them to the machine.

Creating a Plug for the Linksys Adapter
1. Get spare piece of mutli-conductor wire. This is from an old PC power supply.
2. Use wire cutters to cut the insulation a few inches from the end.
3. Slide the shielding down, exposing a gap in center.
4. Bend the wire over the outside, ground part of the plug.
5. Use a zip tie to hold the loop closed.
6. Remove the power plug, tin the loop with solder so that it holds its shape, and outer part is finished.
7. Take another piece of wire and strip an inch of insulator from it.
8. Fold the exposed wire over on itself and twist it together tightly with your finger. This will is the center post of the plug.
9. Twist the center post some more with some pliers to make sure it is strong, then slide it into the hole on the adapter to make sure it fits. If it is too large, squish it a bit with some pliers. If it is still to larger, use a lower gauge wire or start over and trim some of the strands off this wire before bending it over.
10. Tin the center post with solder and make sure it still fits inside the plug’s hole (squish and shape with pliers as needed).
11. Slide the plug into the wire loop, stick the center post into the plug, and use a zip tie to attach the center post to the loop.
12. Wrap in everything together in electrical tape, being careful to not leave any exposed metal.

Making the Connecting Pins
1. Find some spare bits of copper grounding wire from 120V home wiring. I used two gauges, with the slightly smaller one being used for the video cable.
2. Cut six 1.5″ pieces and remove any insulation.
3. Use a hammer and a solid surface, such as an anvil or other heavy piece of metal, to slightly flatten 1/4″ on the end of each pin. This makes it easier to solder the wires to the pins.
4. Sand or scrape off any corrosion on the flat part of the pins.
5. Tin the pins and the wires and solder them together. You will need to hold the pins with a clamp of some sort, as they get burning hot in an instant!
6. When the pins have cooled down, slide some wire-shrink over them and the wires and shrink it (using heat).
7. Mark the ground on the 5V pin differently so that you can remember which is positive and which is ground.

Making the Video Cable
1. Cut the end off an RCA cable.
2. Solder the pins, as above.

Connecting the Pins to the VIC-20
Normally one does not have to deal with pins when plugging in a cable, but the reality is that many connectors are stuffed full of pins and it’s those pins that are doing the real work. With that in mind, if we know what pin goes where, it’s not a big deal to simply slide the pins in one at a time by ourselves. Here is a diagram of the Commodore 64 / VIC-20 power supply:

Keep in mind that the picture of the socket on the bottom left is what you see when looking at the VIC-20, while the circle on the bottom right is what the 7 pin DIN connector on the end of a standard power cable would look like if you were holding in your hand. When manually inserting the pins, it easiest to just refer to the numbers on the socket.

The two 9V pins slide into the top most holes. The 5V ground slides into the bottom middle, while the 5V positive slides into the number five hole immediately to the left of the bottom middle hole.

Connecting the video cable is just as simple. Here is the layout of the video socket, as you would see it when looking at the back of the VIC-20:

Slide the ground pin into ground and the center “signal” pin to hole 4, then connect the other end to the composite in of the TV, monitor, etc. that you will be displaying the VIC’s upon.


And now for the “pre-flight check”, where I opened up my VIC-20 to make sure nothing had been living it, etc.

And the setup, using the composite in on the TV tuner in my PC as a monitor…

And the big reveal!

It works!

And with that accomplished, it’s time to find at least a “Datasette” for it so that I can save and load programs, because the VIC-20 is not so useful without that capability. I am probably better off to use the emulator for now, with the VIC-20 keyboard as a visual aid. I am not sure which is harder, typing on the real and unfamiliar VIC-20 keyboard or trying to figure out what key does what on my PC keyboard when using the emulator… 🙂

Typing in a BASIC program from the manual (left) and running it beside the emulator (right).

What a nerd am I! lol…

VIC-20: Walking Before It Runs

Through my ongoing research into getting my used Commodore VIC-20 working, I have made some progress towards getting it running while spending as little money on it as possible. My $20 VIC-20 came with only the “breadbox” computer and the manual, meaning that in order to fire it up, I need to obtain an AV cable, a monitor/TV, and a power supply. If I want to load any software on it, I will also need a disk drive or a tape deck or a cartridge. As of today I have the following…

Power Supply
– A 9v AC adaptor (from a Linksys router) to use in the creation of a power supply. Despite reading the specs on every “wall wart” AC adaptor in the house, I wasn’t able to find one that outputs 5v at the minimum of 1.5A (I have several at 1 amp, but that’s not really enough to run the VIC-20). Looks like I will need to buy a 7 pin DIN connector and a 5v adaptor so I can wire them together to form a modern, inexpensive power supply.

Monitor
– I setup the video input on my KWorld PC150-U TV Tuner to work with the TVTime software and tested the composite input using a busted DVD player. This should allow me to run the VIC-20 in a window on my main PC monitor! This is probably not an ideal setup, but it does have the advantages of already being paid for and not taking up more room on in my limited desk area. I haven’t used the video inputs on the tuner for years, so it’s nice to know it still works (I generally just use the RCA inputs for audio recording).


Next Steps
– Obtain a 5 pin and a 7 pin DIN connector, as well as a 5v DC 2A adaptor so I can assembly a power supply and a video cable.
– Open up the case to make sure everything is OK before powering it up for the first time in forever. The previous owner stated that it did work the last time it was tested, but I don’t know how many years ago that was.

The Bigger Picture
– I’ll be re-learning Commodore BASIC and the assembly language for the C64, using the VICE emulator, thanks to these great books!
– When I start an actual programming project (a game, of course, some time after I finish RocketTux), I will be writing the BASIC code in Linux and converting it to a native c64 program using C64List, because this will allow me to use Git/GitHub version control system (on the plain text BASIC file). This is ideal from a workflow perspective, but it’s not really what I would consider “retro computing”. Ideally, I would like to get a Commodore 128 or a Commodore 64C, a disk drive, and something that allows me to share data with the PC.
– I have decided that I want to keep my VIC-20 in its natural state, but I would like to get some extra stuff for it, such as a RAM expansion cartridge and a few cartridge games. I might “retrobrite” it, because it has inconsistently yellowed over time, but it’s not super high on my list of priorities.

Well, that’s where I am at right now. Actually, this…

is where I am at right now – my refurbished desk area! Why purple? We had 2/3 of a can left over from when we painted our kid’s room years ago, so I figured what the heck – it wasn’t going to be used for anything else and I like purple more than ratty old beige. I’m thinking it would be fun to make some clear plastic shelves for the right side, complete with a breadboard Arduino LED system, because why not! 🙂

I Bought a Commodore VIC 20 for $20!

Over the past couple months I have been chatting with my friend, Kinshi, about his retro computing hobby and it got me into the spirit as well. The first computer I programmed on (in 1993 or so) was the Commodore 64 in our grade seven class room. While I was given a Commodore 64 around the same time too, I didn’t end up doing a whole heck of a lot with computers until 1998. None the less, I ended up with a soft spot in my heart for the o’l “breadbox” machine. Watch me as I head off on a journey to buy my very own Commodore VIC 20!