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#1 Nateo OFFLINE  

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Posted Mon Mar 5, 2018 5:49 PM

Quick question - on a lot of screenshots I've seen of the CoCo in action with, let's say, Donkey King, the colors are light blue and orange. On my CoCo, all I'm getting is magenta and green. What's the deal here? Thanks all!

#2 thetick1 OFFLINE  

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Posted Mon Mar 5, 2018 6:07 PM

Are you sure you don't have Monkey Kong for the CoCo or another Donkey Kong rip off?

 

http://www.mobygames...oco/monkey-kong

 

192818-monkey-kong-trs-80-coco-screensho

 

http://www.mobygames...ame/donkey-king

 

187214-donkey-king-dragon-32-64-screensh

 

As the recent Donkey Kong looks real good ?

http://www.mobygames...co/donkey-kong_

218814-donkey-kong-trs-80-coco-screensho


Edited by thetick1, Mon Mar 5, 2018 6:10 PM.


#3 BassGuitari ONLINE  

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Posted Mon Mar 5, 2018 6:22 PM

Quick question - on a lot of screenshots I've seen of the CoCo in action with, let's say, Donkey King, the colors are light blue and orange. On my CoCo, all I'm getting is magenta and green. What's the deal here? Thanks all!

 

I had this issue with an old CoCo 1 I used to have--the artifact colors of PMODE4(? whichever PMODE uses artifact colors) showed green and purple instead of blue and orange. Never really nailed down what caused the issue, unfortunately. But there's a resistor(?) in a clear plastic tube enclosure near the RF modulator that seemed to need additional grounding; whenever I poked at it or touched it, the artifact colors improved a bit and became much closer to what they were supposed to be. I never went as far as to actually attempt any soldering, but all my MacGuyver attempts at grounding it resulted in failure (perhaps unsurprisingly).

 

Eventually I just got a different one and ditched it.



#4 Nateo OFFLINE  

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Posted Mon Mar 5, 2018 8:59 PM

Are you sure you don't have Monkey Kong for the CoCo or another Donkey Kong rip off?
 
http://www.mobygames...oco/monkey-kong
 
192818-monkey-kong-trs-80-coco-screensho
 
http://www.mobygames...ame/donkey-king
 
187214-donkey-king-dragon-32-64-screensh
 
As the recent Donkey Kong looks real good ?
http://www.mobygames...co/donkey-kong_
218814-donkey-kong-trs-80-coco-screensho


It's most certainy Donkey King.

I did read somewhere that the PAL colors for the CoCo end up being purple and green due to the differences in artifcating results between the two systems. But I'm in NTSC land, so I have no idea whats going on.

#5 JamesD OFFLINE  

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Posted Tue Mar 6, 2018 1:32 AM

I thought PAL shows CoCo PMODE 4 graphics output as B&W.



#6 Nateo OFFLINE  

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Posted Tue Mar 6, 2018 6:42 PM

I asked on the CoCo Facebook group, and I got my answer! It's the color burst circuit: https://sites.google...-yellow-bar-fix

Edited by Nateo, Tue Mar 6, 2018 6:42 PM.


#7 Mr SQL OFFLINE  

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Posted Wed Mar 7, 2018 7:53 AM

I remember seeing Color Computer 2's that output green instead of blue at the Radio Shack where the Computer Club I was in used to meet circa 1985. I also saw Color Computers that had real lowercase characters via a new revision of the 6847 VDG, they may have been the same model.  



#8 JamesD OFFLINE  

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Posted Wed Mar 7, 2018 8:22 AM

I remember seeing Color Computer 2's that output green instead of blue at the Radio Shack where the Computer Club I was in used to meet circa 1985. I also saw Color Computers that had real lowercase characters via a new revision of the 6847 VDG, they may have been the same model.  

The color issue is largely the TV settings.
NTSC and artifact colors can be different from one TV to the next.



#9 Mr SQL OFFLINE  

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Posted Wed Mar 7, 2018 10:23 AM

The color issue is largely the TV settings.
NTSC and artifact colors can be different from one TV to the next.

 

It was only the artifact colors that were affected, the light green text screen was the same.

 

The article suggests the colorburst was always generated on phase A, but we often had to reset until the artifact palette switched up the blue and red correctly. I had thought that it was switching phase when that happened.



#10 JamesD OFFLINE  

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Posted Wed Mar 7, 2018 11:30 AM

 

It was only the artifact colors that were affected, the light green text screen was the same.

 

The article suggests the colorburst was always generated on phase A, but we often had to reset until the artifact palette switched up the blue and red correctly. I had thought that it was switching phase when that happened.

Not sure where you are going with this.
"It was only the artifact colors that were affected, the light green text screen was the same" as in, unaffected because it didn't use artifacts.
 



#11 Mr SQL OFFLINE  

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Posted Wed Mar 7, 2018 1:58 PM

Not sure where you are going with this.
"It was only the artifact colors that were affected, the light green text screen was the same" as in, unaffected because it didn't use artifacts.
 

 

It was a computer club setting so I'm pretty sure we tried other CoCo's on the same TV to compare. We also encountered CoCo's with a slightly different shade of green on the text screen and models with lowercase in the 6847.






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