Commodore 64 Help

[mattimeo310]

I didn't know whether to post this in Computers or Technical/Restoration but I just picked up a Commodore 64 and the text is flashing different colors. Is there a setting or some command which will fix this?

Thank You.

[Wookie]

Sounds like a hardware problem, either the VICII chip or bad RAM. Might also be the r/f modulator and/or cable, though that's less likely.

Check out these pages for tons of Commodore diagnostic and repair info:
personalpages.tds.net/~rcarlsen/cbm.html

Good luck!

[mattimeo310]

I am using a NES RF cable, I don't know if that would effect it or not...

[Flack]

Does it only do it at the main screen? If you load up a game, do the colors still cycle? I agree, it sounds like a hardware problem.

[mattimeo310]

Does it only do it at the main screen? If you load up a game, do the colors still cycle? I agree, it sounds like a hardware problem.

Yes when I load up a game the colors still cycle, judging from that link that was posted it most likely seems to be a problem with the color SRAM.

[Wookie]

I am using a NES RF cable, I don't know if that would effect it or not...

Before tearing it apart, try a different cable. The C64's rf signal is too weak to reliably operate the autoswitching NES cable (same with Sega switches and other similar units). That might clear it up.

[kedawa]

C64 originally used an RF box with a mechanical switch, so yeah.

[mattimeo310]

I plugged it into a generic rf box I had laying around and still no luck. From what I read it seems like it would be a problem with the SRAM but I'm really not the most skilled technical guru in the world.

[Pete Rittwage]

SRAM failure would be really rare. That will likely be bad power supply or PLA chip.

[cityside75]

I plugged it into a generic rf box I had laying around and still no luck. From what I read it seems like it would be a problem with the SRAM but I'm really not the most skilled technical guru in the world.

Just to confirm, was your generic rf box a manual switcher? I can confirm what the others have said that the C64 will not work correctly with any auto switching unit that I've seen. Last I checked Radio Shack still sells the manual switches if you need one.

[icbrkr]

Usually a dying power supply will prevent it from booting (or taking multiple flicks of the switch to get it to turn on) or some more fatal weirdness (i.e., lockups). It does sound like the color ram is on its way out if it's being used with a mechanical switch box.

[T2KFreeker]

Could also be the SID chip. I have seen this happen in the past when the SID starts to go bad. Might want to pull the chip and make sure all of the connections are clean and tight.

[Wookie]

Could also be the SID chip. I have seen this happen in the past when the SID starts to go bad. Might want to pull the chip and make sure all of the connections are clean and tight.

Really? A failing SID can cause video anomalies? That's a new one on me.

[T2KFreeker]

Really? A failing SID can cause video anomalies? That's a new one on me.

Yes it can. Can also cause controller issues.

[icbrkr]

Yep, the SID has a few lines hooked up to the joystick port for paddle decoding. One of the reasons why you shouldn't (but do anyway) hook up a controller while it's turned on.