Old Comp Vid Mod-- Activision games only in B&W?

Includes Atari 2600, Nintendo 8-bit, Sega Master System, MSX and more!

Moderator: Moderators

Post Reply
Murph74
Posts: 7
Joined: Fri Nov 10, 2006 8:09 am

Old Comp Vid Mod-- Activision games only in B&W?

Post by Murph74 »

Hi folks-- just got around to trying a Composite Mod on my own (still hoping for a Long Horn Svid mod someday! ) :P and got it almost working. (Composite only, RF died as soon as I tested with the comp mod in place-- is that normal?)

This is the simple 2 pots/22 ohm resistor method. When first hooked up as Video Only, played Pitfall and Grand Prix with no issue as test games. Now that I've added audio and place the perfboard in the atari case (not closed up yet, I made that mistake too many times in the past!), Pitfall and Grand Prix are coming up in B&W only, no matter of the pots adjustment or the mainboard adjustment.

Other games tested include Name This Game, Mr Do, Ms Pac and Asteroids. All of those come up in color no problem. Any ideas why this only seems to be an Activision issue? I can test more games if needed....

Look forward to responses!

BTW< my setup is the Atari going thru a Radio Shack DVD recorder input to a LCD projector (sanyo z3). Again worked fine before I wired in Audio.

Murph

Update: after further testing, I'm still getting most Activision games in black & white, with the exception of Spider Fighter. Other games that check OK include Infiltrate, Sea Hunt, Winter Games, most Atari brand games, Pete Rose Baseball, pretty much anything I throw at it. Outside of Activision games, only Pac Man and Frogger seem to have the same problem in showing black and white.
tom61
Senior Member
Posts: 1517
Joined: Fri Mar 25, 2005 6:51 pm

Post by tom61 »

Is the Color/BW switch set to color? I've found many games will display in color, even when the switch is set to BW. Other than that, double and triple check your wiring.
Murph74
Posts: 7
Joined: Fri Nov 10, 2006 8:09 am

Post by Murph74 »

Hmm-- the color/BW switch doesn't do anything on any of the games. I was under the impression that the composite mod bypassed that switch.

I also tried to run it thru a VCR for 'stabilization' with no luck, and tried a 13" tube TV's composite input with the same symptoms.

Odd that it worked fine initially, but now it doesn't since Audio was hooked up.

Could using a common ground on audio and video cause this? I ran one wire from a shield pad point to the audio then to the video ground daisy chain style.
Murph74
Posts: 7
Joined: Fri Nov 10, 2006 8:09 am

Post by Murph74 »

Murph74 wrote:Hmm-- the color/BW switch doesn't do anything on any of the games. I was under the impression that the composite mod bypassed that switch.

I also tried to run it thru a VCR for 'stabilization' with no luck, and tried a 13" tube TV's composite input with the same symptoms.

Odd that it worked fine initially, but now it doesn't since Audio was hooked up.

Could using a common ground on audio and video cause this? I ran one wire from a shield pad point to the audio then to the video ground daisy chain style.
Well, the composite mod in this for does NOT bypass the BW/Color switch. Turns out that was the culprit. I tried the mod on a different 4switch system, it worked as is. I changed the switch out on the original system, and it's now working too. And all is good. :)
Post Reply