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Found vic 20, trying to get it working

M

madMatador78

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Oct 18, 2015
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35
Location
Northern IL
Hello, New to the forum, New to Commodore.

Found this at a flea market yesterday, a vic 20, with cartridges and Cassettes, cassette player and cables for 10 bucks.

It had a composite cable set, plugged it in and no picture. It also had what looked to be a rf modulator, tried that and still no picture. Power lite illuminates, cassette player seems to work. Appears to play, rewind, fast forward.

The composite cable set appeared to have some issues, the pins were recessed much further than they should have Been, tried taking the plug apart, but it just disintegrated. Much like The joystick that came with it.

Found the pinout for the video plug, tried outputing to a tv, get flashes on the screen like there is something there, but can't get a picture. Ordered a New cable off eBay, then well see what that does. May try and re seat the chips inside. Anything I'm missing?
 
Bump. Anything?

I'm starting to get into retro computing and would like to know some more about this old machine. New cable is on the way. Is there a source for software or anything like that?
 
I'm not really too sure of anything. Hopefully having a good cable will show something.

I can tell you that its the older style as it has the 2 plugs insted of the din for the power.
 
Time to crack it open. Depending on what version it is (are there colored bars on the VIC-20 label like this, or is it more like this?) will determine what chips are inside, and where to look for things.

In both versions, the VIC chip is the most likely culprit, and unfortunately it's also the hardest to find. It will be labeled MOS 6560 (NTSC version) or 6561 (PAL version). Generally it's under a small metal box inside the newer VIC-20s (color logo, AKA the "cost reduced" or CR version). On this photo it's under the perforated box. Pry the top off that and let us know if you have a 6560 or a 6561.

Outside of the VIC chip, you can of course run into problems with the other chips which will exhibit some similar behaviors. The most common one I hear of is the CPU being held in RESET by having a pin grounded. Make sure there's no crap/dirt/metal shavings/etc on the mainboard.

You might also check out the Denial forums , as that's where the die-hard VIC-20 folks congregate.
 
Its like the second one you posted. I wasn't feeling like I was getting a good connection with the av cable I was trying to rig up so I could see if it had any picture. Thank you for the information. I will open it up tonight and see what I find, and post back.
 
There's signs of life!!!

While I can't get video, 95 percent sure it's a dodgy cable, I took it apart and re seated all the chips I could. I then turned it on and loaded a program off cassette. It stopped at 27 on the counter, I assume it stops once it's loaded? Then I powered it down and did it again and it did the same. I assume this is good news??
It is an ntsc based on the info here. So that's good as well.

Edit: obviously I couldn't see if it loaded or not, but I'm guessing since the tape stopped in the same place twice that this means it's working? I hope my excitment isn't misplaced.
 
KC9UDX said:
Are they really more rare? Most of them I've seen are like that.
Click to expand...

Not more rare, per se, but more coveted. The later ones are "cost reduced" in that they found ways to economize the board layout. They ran cooler, theoretically, which made the VIC chips last a bit longer (this was mainly accomplished by moving the AC/DC conversion to an external brick on the powersupply, just like the C64 -- earlier version have all that circuitry built-in).

I think most people just like the earlier ones, partly because they're earlier models, partly because they have a cooler (more PET-like) font on the keys. :D
 
Something doesn't jibe here. I've never actually seen a Vic that I know of that had the two-prong power plug. But most of them I've seen had the earlier label. I just checked mine to make sure, and that is the way it is: DIN plug and black/silver label.
 
KC9UDX said:
Something doesn't jibe here. I've never actually seen a Vic that I know of that had the two-prong power plug. But most of them I've seen had the earlier label. I just checked mine to make sure, and that is the way it is: DIN plug and black/silver label.
Click to expand...

Interesting. I only own a CR "rainbow" version, so I've never really paid attention to the earlier models beyond reading a bit about them. I wonder at what point they switched labels versus when they switched the main board design?
 
I don't know. I'll have to open mine up, and see if it's really a CR board, or maybe an early board with the different power supply.

I don't know where I got this information, but I for some reason think that the power supply change happened very early, before the CR version came about.
 
This site (near the bottom) has this:

The original Vic-20 uses a 2 prong power supply. This model can also be identified by it’s monochromatic name badge on the top of the case.

The later cost-reduced Vic-20 uses a circular DIN connector for it’s power supply. It is identical to the power connector found on the Commodore 64. These units typically had cooler internal case temperatures and did not require a large internal heat sink like the first generation of Vics.

The cost reduced Vic could also be identified by their colorful name badges. Enthusiasts sometimes refer to these as Rainbow Vics.
Click to expand...

However, I'm not sure if that's a definitive source... I bet the folks over at Denial would know for sure.
 
Very clean indeed. Much better than mine was, though to be fair, I sat mine on a shelf - not in a box - in 1988 when I got an IBM XT clone, and it sat there until a couple years ago.

You definitely have the earlier board design. Looks like a VIC 6560, which is indeed the NTSC version. Let us know how that new cable works!

Edit: Found it! I was looking for this all morning. It's a simple list of what the major components on the board do. http://www.zimmers.net/anonftp/pub/cbm/firmware/computers/vic20/README
 
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Good news! After some more fussing around, I got a picture! Ill post pics tomorrow, my tablet doesn't seem to want to post pictures. But it seems to all be working!! Loaded some cassette programs, and wrote a small program and saved it to verify function of tape player.

Noob question, but how does one load off cartridges?
 
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