[Coco] 6847 Video (newbie question)

Luis Antoniosi (CoCoDemus) retrocanada76 at gmail.com
Thu Nov 6 15:58:26 EST 2014


Yep diddier,

I was to mention that S-Video is much more available (even some 200x
monitors still have it). And use less cables and don't need this crappy gbs
board.

The S-video circuit is much more simpler and require less color tuning.


Luis Felipe Antoniosi



On Thu, Nov 6, 2014 at 3:45 PM, didier derny <didier at aida.org> wrote:

> This is the result:
>
> http://6809.eu/t1.jpg
>
> another test:
>
> http://6809.eu/t2.jpg
> (colors better on the real screen)
>
> Btw I don’t have a coco3 but a coco2
>
> I've not soldered floating wire to the 6847
> But I've soldered a socket (with pins 1,3,8,10,12,13,14 cut)
> [if I remove my connector, the tv modulator is still working]
>
> Then on this improvised connector I connect either
> The composite or the ypbpr interface.
>
> The ypbpr interface is just a bunch of wires
> Connected to a small breadboard
>
> http://6809.eu/if.jpg
>
> now that I have a result I'll rebuilt it on a larger breadboard
> with some adjustable resistor to try to improve the result
>
> for example, the black is not really black
>
> then I'll move to a real pcb
>
>
>
> -----Message d'origine-----
> De : Coco [mailto:coco-bounces at maltedmedia.com] De la part de Daniel
> Campos
> Envoyé : mercredi 5 novembre 2014 22:47
> À : CoCoList for Color Computer Enthusiasts
> Objet : Re: [Coco] 6847 Video (newbie question)
>
> Very good already! But please do the command bellow and take a picture,
> please.
>
> FOR I=32 TO 255:? CHR$(I);:NEXT
>
> Daniel
>
> Em 05/11/2014 19:44, didier derny escreveu:
> > I modified the value of some resistors, I get a better result
> >
> > This is what I get:
> > http://6809.eu/ypbpr3.jpg
> >
> > for reference the composite:  (it's just ugly) :(
> > http://6809.eu/composite.jpg
> >
> >
> > Modification made to Luis schematics:
> >
> > 150 ohms resistor between emitter of the first transistor and GND
> replaced by 330 ohms
> > 75  ohms resistor Cb out  and Cr out    replace by 37.5 ohms  (2
> resistors 75 ohms in parallel)
> >
> > All le settings of the GBS 8220 are set to default
> >
> >
> > --
> > didier
> >
> > -----Message d'origine-----
> > De : Coco [mailto:coco-bounces at maltedmedia.com] De la part de didier
> > derny Envoyé : mercredi 5 novembre 2014 21:45 À : 'CoCoList for Color
> > Computer Enthusiasts'
> > Objet : Re: [Coco] 6847 Video (newbie question)
> >
> > In fact it was a problem with the breadboard (a stupid bad contact)
> >
> > http://6809.eu/ypbpr2.jpg
> >
> > I'll try to find a color test...
> >
> > I find the black really good compared to composite With the composite
> > the letter S looks a little bit like 8
> >
> > I don’t find the colors ok, "too clear"
> > (looks better on the image, that it really is)
> >
> > --
> > Didier
> >
> >
> >
> > -----Message d'origine-----
> > De : Coco [mailto:coco-bounces at maltedmedia.com] De la part de Luis
> > Antoniosi (CoCoDemus) Envoyé : mardi 4 novembre 2014 23:15 À :
> > CoCoList for Color Computer Enthusiasts Objet : Re: [Coco] 6847 Video
> > (newbie question)
> >
> > Inverted transistor ? Did you check the datasheet ? They change EBC pins
> from vendor to vendor.
> >
> >
> > Luis Felipe Antoniosi
> >
> >
> >
> > On Tue, Nov 4, 2014 at 5:11 PM, didier derny <didier at aida.org> wrote:
> >
> >> This is what I get, I have an image but obviously I have a problem
> >>
> >> This is the 3 signals   Y + PB + PR
> >> http://6809.eu/ypbpr.jpg
> >>
> >> I tried with only Y connected  (I expected a black and white image)
> >> http://6809.eu/y.jpg
> >>
> >> It's connected to a GBS 8220
> >>
> >> --
> >> Didier
> >>
> >>
> >>
> >> -----Message d'origine-----
> >> De : Coco [mailto:coco-bounces at maltedmedia.com] De la part de Luis
> >> Antoniosi
> >> (CoCoDemus)
> >> Envoyé : vendredi 31 octobre 2014 22:04 À : CoCoList for Color
> >> Computer Enthusiasts Objet : Re: [Coco] 6847 Video (newbie question)
> >>
> >> It works, but you need to make a driver:
> >>
> >> https://pbs.twimg.com/media/BCb7-hoCEAAJm22.jpg:large
> >>
> >> When I used my it suffered from severe jumps time to time. maybe you
> >> have better luck and a better board.
> >>
> >>
> >> Luis Felipe Antoniosi
> >>
> >>
> >>
> >> On Fri, Oct 31, 2014 at 3:58 PM, didier derny <didier at aida.org> wrote:
> >>
> >>> I just received a GBS 8220 and I was wondering if the YPBPR entries
> >>> of the GBS 8220
> >>>
> >>> Were compatible with the Y phiA phiB of the 6847 ?
> >>>
> >>>
> >>>
> >>> Are they the same signal with another name or something different ?
> >>>
> >>>
> >>>
> >>> Not really understood fig 10 of the 6847 datasheet
> >>>
> >>>
> >>>
> >>> I often used composite or rgb but never  YPBPR or the signal of the
> >>> 6847
> >>>
> >>>
> >>>
> >>> Any idea ?
> >>>
> >>>
> >>>
> >>> Thanks
> >>>
> >>>
> >>>
> >>>
> >>>
> >>> --
> >>>
> >>> Didier
> >>>
> >>>
> >>>
> >>>
> >>>
> >>>
> >>> --
> >>> Coco mailing list
> >>> Coco at maltedmedia.com
> >>> https://pairlist5.pair.net/mailman/listinfo/coco
> >>>
> >> --
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> >> Coco at maltedmedia.com
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> >>
> >>
> >> --
> >> Coco mailing list
> >> Coco at maltedmedia.com
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> >>
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> > Coco mailing list
> > Coco at maltedmedia.com
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> >
> >
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> >
> >
>
>
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>
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