Atari 400 showing different colors.

[NightSprinter]

Just curious, is there any reason as to why an Atari 400 or 800 would end up showing purple when it's supposed to be blue? It never got as bad as it was before, but anything that shows blue (basic/notepad screen, Pac-Man maze walls, shields in Star Raiders) just outright shows purple instead. I've tested it on several different televisions and all show the same problem. What would cause this?

[puppetmark]

Just curious, is there any reason as to why an Atari 400 or 800 would end up showing purple when it's supposed to be blue? It never got as bad as it was before, but anything that shows blue (basic/notepad screen, Pac-Man maze walls, shields in Star Raiders) just outright shows purple instead. I've tested it on several different televisions and all show the same problem. What would cause this?

 

It could be as asimple as the color potentimeter is out of adjustment. I don't remember where it is on a 400 /800 but I would try that first.

[Rybags]

It should be accessable from the bottom of the case.

 

If you search the forums, I think under subjects like "palette", "colours" or similar, there are numerous programs you can DL which show all 256 colours at once - very handy for fine tuning the colour pot or your TV settings.

[analmux]

I've tried this some time ago.

 

Is there some convention such that I can check whether my potentiometer setting is correct??

 

Could be good to know when you want to choose colours for a gfx picture.

Edited June 13, 2008 by Analogue Multiplexer

[Rybags]

I think the best bet is getting white and red right, as any drift on those two will be very obvious. Also, they're much less represented than the greens and blues (although the adjacent hues to red do have a substantial red component).

 

I played with the trimmer on my 800XL once - it's fairly easy to get a "personalised" setting you like, but not deviate too much from the "standard".

[NightSprinter]

Have a picture of where that pot is on the 400?

[Rybags]

There should be a hole in the case just small enough to fit a precision screwdriver into. I've read advice that says use a plastic driver, but I just used a normal one.

 

I'm not sure if it's as accessable on the 400 since it has the heavy shielding. Someone else with one should know.

[sup8pdct]

There are 2 adjustments on the 400/800.

The one accessible from the bottom of the case is to do with the rf modulator, something to do with mixing or something. That one, you MUST use a plastic adjust tool

The colour adjust pot is from the back. looking from the back, on the lefthand side of the cooling grills near the top, you should be able to see a hole through the shielding behind the plastic grill.

That is the colour adjust pot. give it very small tweaks.

 

James

[NightSprinter]

Thanks everyone. Got the 400 back to the color set I needed it at. Now I have a fully-enjoyable 64k machine from the first gen (four joystick ports).

[Velcro_SP]

Thanks everyone. Got the 400 back to the color set I needed it at. Now I have a fully-enjoyable 64k machine from the first gen (four joystick ports).

 

Very sweet. Have you considered getting a more-regular keyboard to go over the membrane one? I think those are still available at some vendors. Those first generation Atari machines, the 400 and 800, really are something.

[+Larry]

Thanks everyone. Got the 400 back to the color set I needed it at. Now I have a fully-enjoyable 64k machine from the first gen (four joystick ports).

 

Just curious -- what mod or memory card did you use to get a 64K 400?

-Larry

[NightSprinter]

Thanks everyone. Got the 400 back to the color set I needed it at. Now I have a fully-enjoyable 64k machine from the first gen (four joystick ports).

 

Just curious -- what mod or memory card did you use to get a 64K 400?

-Larry

 

 

I can't remember to be honest. This was how the system was when I got it from eBay.