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Improved Color For Your 4-Switch Woody: A Public Service Bulletin


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#26 rednakes1 OFFLINE  

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Posted Sun Oct 16, 2016 8:37 PM

Okay, so I just tried it on my Rev 13 four-switch woody 2600. Huge difference! Attached is a grid of photos, with the 'Before mod' on the left, and the post-mod on the right. I've also attached a clear photo of the 820 Ohm resistor I soldered on.

Thanks for sharing this mod. Next I will work on an AV mod because the RF is very fuzzy.

Attached Thumbnails

  • IMG_1698.JPG
  • IMG_1700.JPG

Edited by rednakes1, Sun Oct 16, 2016 8:44 PM.


#27 ubersaurus OFFLINE  

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Posted Sat Nov 5, 2016 9:28 PM

I think this is exactly what mine needs - I've noticed the color is off from my Jr, and those photos show the exact colors I see on Pac Man, for example.

#28 Level42 OFFLINE  

Level42

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Posted Sun Nov 6, 2016 4:31 AM

Yes my 4-switch Sunnyvale with Rev.13 PCB must be missing this resistor too as the colors (despite turning them up to the maximum on my TV) are still not full enough.

Gotta find my resistors....


Edited by Level42, Sun Nov 6, 2016 4:31 AM.


#29 Level42 OFFLINE  

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Posted Sun Nov 6, 2016 4:34 AM

Okay, so I just tried it on my Rev 13 four-switch woody 2600. Huge difference! Attached is a grid of photos, with the 'Before mod' on the left, and the post-mod on the right. I've also attached a clear photo of the 820 Ohm resistor I soldered on.

Thanks for sharing this mod. Next I will work on an AV mod because the RF is very fuzzy.

 

You did a very neat job installing that resistor. The isolation tape is not really needed, there is an insulating lacquer layer over the PCB.....but it won't hurt of course :D



#30 rednakes1 OFFLINE  

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Posted Sun Nov 6, 2016 9:35 AM

Thanks for the tip, yeah I eventually removed the tape and it didn't do any harm. One thing I noticed with the video quality is that you may see a row of white dots on the left side of the screen. My 2600 Jr. also has the same effect so I guess it's a symptom of the extra saturation.

#31 Level42 OFFLINE  

Level42

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Posted Mon Nov 7, 2016 3:34 PM

Mmmm, doing the mod now....your pic really helps (saves counting pins ;) )



#32 Level42 OFFLINE  

Level42

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Posted Mon Nov 7, 2016 4:20 PM

WOW !!!! What a difference one little resistor can make !!!

 

Finally the Demons of Demon Attack look like I remember them (well, I mean almost like I remember them, I am in PAL territory so I grew up with the (less colorful) PAL 2600 and games, but anyway, the colors are much much richer now !

 

Excellent tip :D Pretty weird is this is _so_ old and must be well known since it was an official Atari bulletin.



#33 Keatah OFFLINE  

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Posted Mon Nov 7, 2016 4:34 PM

Can someone post a pic of Video Pinball running on a modded machine?

#34 ubersaurus OFFLINE  

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Posted Sun Mar 12, 2017 5:36 PM

I've got kinda funky colors on a revision 17 board that had the resistor added on. I don't know if that revision needs it or not, but yeah - some colors are blurry and indistinct, everything is kind of washed out, some colors aren't easily distinguished (like Pitfall Harry's shirt and the background). Anyone know if I should try removing it or not?



#35 mojoatomic OFFLINE  

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Posted Sun Mar 12, 2017 6:25 PM

Yes, remove it - the resistance had been doubled on the board as it already has the resistor from the factory. 



#36 ubersaurus OFFLINE  

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Posted Sun Mar 12, 2017 8:11 PM

Well that is the other thing - there was no resistor already on the underside of the TIA when this was attached. So you're saying that the one designed for the system is already elsewhere on the board?

#37 mojoatomic OFFLINE  

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Posted Sun Mar 12, 2017 10:12 PM

Yes, look at the topside of the board and find R234



#38 ubersaurus OFFLINE  

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Posted Mon Mar 13, 2017 7:26 AM

Cool - I'll give that try tonight. I had my suspicions, but figured I'd check with folks who may know for sure. Thanks!



#39 mojoatomic OFFLINE  

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Posted Mon Mar 13, 2017 7:28 AM

Cool - I'll give that try tonight. I had my suspicions, but figured I'd check with folks who may know for sure. Thanks!

Don't remove R234, just the resistor that was added to the reverse side of the board - 



#40 ubersaurus OFFLINE  

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Posted Mon Mar 13, 2017 7:41 PM

That definitely fixed the color issue. Now if only I could suss out why certain colors seem so fuzzy and indistinct on certain backgrounds (like the blue ghost in Ms. Pac-Man, or Pitfall Harry's shirt), this rev 17 board would be in business.



#41 Kapikui OFFLINE  

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Posted Sun Mar 19, 2017 9:45 PM

Is this something for the RF output only, or does it work for the composite mods as well?



#42 Hank Rearden OFFLINE  

Hank Rearden

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Posted Mon Mar 20, 2017 5:39 AM

Is this something for the RF output only, or does it work for the composite mods as well?

I've been wonder this same thing myself.



#43 DrVenkman OFFLINE  

DrVenkman

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Posted Tue Mar 21, 2017 4:54 PM

I've been wonder this same thing myself.

 

I haven't dug into the schematics but it should work for all video output. With this little tweak, you're literally modding right at the source of the video signal for the entire system, as it leaves the TIA chip.






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