Re: Tempest Color Vectors

Ok, one last thing I just remembered... If my machine sits east-west, the screen colors are all messed up similar to that. I even used a manual degaussing coil on it and it didn't help. Set it back to north-south and it looks fine. Except if it works fine with the other board then it is probably the 74x89 Ram.
---- Rodney Massman <rmassman@hotmail.com> wrote:
> Checked it with both a logic probe and scope. I’m getting like signals in comparison with the good working board and bad.
> Getting the same analog signals from 4,6,10,12. Digital type signals from 5,7,9,11. I’ve got some ic’s coming to piggyback, but that’s not one of them. Couldn’t source it.
> I think what’s throwing my scope and probe signals is that I am getting one, just not the right color.
> Ordered a stock of:
> SN74LS175N
> SN74LS139AN
> SN74LS32N
> SN74LS399N
> SN74LS164N
> SN74LS174N
> I don’t have much of a stock of TTL’s to test with. Hoping they piggyback well.
>
> From: Kevin Moore
> Sent: Saturday, December 08, 2012 6:58 AM
> To: vectorlist@vectorlist.org
> Subject: Re: VECTOR: Tempest Color Vectors
>
> Have you checked the color ram at P9?
>
>
>
> On Sat, Dec 8, 2012 at 5:17 AM, Rodney Massman <rmassman@hotmail.com> wrote:
>
> Been working on a Tempest for a friend. At first there was no video but the game played fine.
> I found a broken trace between K5 and K3 as someone long ago attempted to replace a 2114
> and in the process, burnt a trace.
> So I got video back, however have come across the most peculiar problem. At first I thought it
> was a simple issue of the color transistors, so I replaced Q2-4. Nothing changed. I also replaced Q8-10.
> I am completely missing Red, Green and Yellow. Has anyone else come across this problem?
>
> Bad color vectors:
> http://i269.photobucket.com/albums/jj63/rmassman/IMG_3111.jpg
> http://i269.photobucket.com/albums/jj63/rmassman/IMG_3146.jpg
>
> What it should look like:
> http://i269.photobucket.com/albums/jj63/rmassman/IMG_3112.jpg
> http://i269.photobucket.com/albums/jj63/rmassman/IMG_3149.jpg
>
> Thanks for any help.
>
> Rodney

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Received on Sat Dec 8 14:29:07 2012