[Coco] [HW] Coco 3 video output corrupt when using cart port

[Mike Pepe]

I would also suggest using one of the other outputs to see if the
problem follows the CoCo or is specific to that particular monitor.

1702's are pretty vintage these days.

> -----Original Message-----
> From: coco-bounces at maltedmedia.com [mailto:coco-
> bounces at maltedmedia.com] On Behalf Of Brian Sturk
> Sent: Friday, February 20, 2009 4:21 PM
> To: CoCoList for Color Computer Enthusiasts
> Subject: Re: [Coco] [HW] Coco 3 video output corrupt when using cart
> port
> 
> Hi Robert,
> 
> Thanks for the ideas.  The fringing seems to be on a 40 columns.
> I sent an email out a little while ago thinking a warm reset helps but
> not it's not exhibiting the issue anymore.  I wonder if it's thermal
> related (i.e. being on for a certain amount of time?).
> 
> I'll try and narrow something down...
> 
> ~telengard
> > Brian Sturk wrote:
> >
> >>   On a black screen I can see hints of orange and blue.  It's
almost
> >> like random repainting of the screen *and* the magnetic field
> >> effect.  Definitely weird.
> >>
> >> thanks for the help, I'll report back,
> >> ~telengard
> >>
> >
> > As Tim suggested, re-seating all socketed chips is a good idea even
> if
> > it does not help with this problem. Tandy did not use gold plated
> > contacts so a fresh surface can't hurt and could help.
> >
> > The orange and blue, is that fringing around text with a 40 or 80
> > column screen? If so, it is artifact colors typical of composite
> > video. Some screen colors will make the effect worse than others.
> > There is only one way to get rid of it completely and that is by
> > patching Basic.
> > If this is the source of your colors, I'd suggest using a 40 column
> > screen with a white background and black letters. Enter
> > WIDTH40
> > CLS5
> >
> > If the orange and blue is artifacts and you get a disk system to
make
> > it easy to SAVE and RUN programs, the following will turn off the
> > color burst signal and remove artifacts.
> >
> > 10 POKE&HE033,16:REM width 32 screen
> > 20 POKE&HE03C,19:REM width 40 screen
> > 30 POKE&HE045,19:REM width 80 screen
> >
> >
> > --
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> > Coco at maltedmedia.com
> > http://five.pairlist.net/mailman/listinfo/coco
> 
> 
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