[Coco] The chinese crt9128 works!

[Luis Antoniosi (CoCoDemus)]

this crt chip is quite particular it's a complete composite video solution,
it only needs a static ram and a clock

http://pdf.datasheetarchive.com/indexerfiles/Scans-029/ScansU3X2870.pdf


On Fri, Oct 18, 2013 at 10:41 PM, mike delyea <mdelyea at gmail.com> wrote:

> Just curious - this board doesn't require any shielding?  From memory,
> didn't all the composite video hacks require shielding?
>
>
> On Fri, Oct 18, 2013 at 9:56 PM, Luis Antoniosi (CoCoDemus) <
> retrocanada76 at gmail.com> wrote:
>
> > well it's an old prototype pak that i'm reproducing.
> >
> >
> >
> >
> > On Fri, Oct 18, 2013 at 7:47 PM, chris <cralt at comcast.net> wrote:
> >
> > > Hello,
> > >
> > > I must have missed the other threads about this card.
> > >
> > > Is this a project you guys are building or is this an old card? What is
> > > "osh park"?
> > >
> > > I have a coco2b and sIDE. I have a multi-pak on the way and would love
> to
> > > be able to use my coco as an 80col terminal!
> > >
> > > Thanks,
> > > -Chris
> > >
> > > On Oct 18, 2013, at 7:18 PM, Luis Antoniosi (CoCoDemus) wrote:
> > >
> > >  there is a mistake on the previous schematics I did. But the resistors
> > are
> > >> all used.
> > >>
> > >> There is one resistor under the RCA connector. In this pic you can see
> > one
> > >> of its end under the RCA:
> > >>
> > >> https://pbs.twimg.com/media/**BUpSDG7CQAAvxfJ.jpg:large<
> > https://pbs.twimg.com/media/BUpSDG7CQAAvxfJ.jpg:large>
> > >>
> > >>
> > >>
> > >> On Fri, Oct 18, 2013 at 6:21 PM, Tormod Volden <
> lists.tormod at gmail.com
> > >> >wrote:
> > >>
> > >>  On Fri, Oct 18, 2013 at 11:58 PM, Tormod Volden wrote:
> > >>>
> > >>>> On Fri, Oct 18, 2013 at 4:21 PM, Luis Antoniosi (CoCoDemus) wrote:
> > >>>>
> > >>>>> I will proceed with the prototype in wire-up and they I will make
> few
> > >>>>>
> > >>>> test
> > >>>
> > >>>> cards. I'll be putting the card on osh park in case you guys want to
> > >>>>>
> > >>>> make
> > >>>
> > >>>> your own.
> > >>>>>
> > >>>>
> > >>>> Thanks for sharing this! Just looked at your design again. You are
> not
> > >>>> hooking up the intensity signal (INTOUT, pin 8), isn't that missing
> an
> > >>>> opportunity?
> > >>>>
> > >>>
> > >>> On what do you base the choice of resistor values (22 and 25 Ohm) on
> > >>> the output stage? The Disto design uses 470 Ohm to ground and 10 Ohm
> > >>> in series. On your PHB board I think I can see 220 (or 330?) and 15
> > >>> Ohm close to the output socket although I am not sure where in the
> > >>> circuit they are.
> > >>>
> > >>> Tormod
> > >>>
> > >>> --
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> > >>> Coco at maltedmedia.com
> > >>> http://five.pairlist.net/**mailman/listinfo/coco<
> > http://five.pairlist.net/mailman/listinfo/coco>
> > >>>
> > >>>
> > >>
> > >>
> > >> --
> > >> Long live the CoCo
> > >>
> > >> --
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> > >> Coco at maltedmedia.com
> > >> http://five.pairlist.net/**mailman/listinfo/coco<
> > http://five.pairlist.net/mailman/listinfo/coco>
> > >>
> > >
> > >
> > > --
> > > Coco mailing list
> > > Coco at maltedmedia.com
> > > http://five.pairlist.net/**mailman/listinfo/coco<
> > http://five.pairlist.net/mailman/listinfo/coco>
> > >
> >
> >
> >
> > --
> > Long live the CoCo
> >
> > --
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> > Coco at maltedmedia.com
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> >
>
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>



-- 
Long live the CoCo