[Coco] S-Video mod for Coco1

Tue Oct 1 09:45:04 EDT 2013

according to the scheme you post the output is NOT 12V otherwise it would
burn your monitor.

just measure it with a multimeter before.

This should work on a dragon.

On Tue, Oct 1, 2013 at 8:44 AM, Ken H. <dragon.atv at gmail.com> wrote:

> The input for the LM1889 is 12V.
>
> But I think that the chroma subcarrier output on pin 13 is not, if we can
> trust the Spectrum service manual
>
> http://www.1000bit.it/support/manuali/sinclair/zxspectrum/sm/sec4_4.html#ic14
>
>
>
> On Tue, Oct 1, 2013 at 2:45 PM, Retro Canada <retrocanada76 at gmail.com
> >wrote:
>
> > but is 12v right ?
> >
> > On 2013-10-01, at 3:40 AM, "Ken H." <dragon.atv at gmail.com> wrote:
> >
> > Luis, your bet on pin 13 of the LM1889 is right on target!
> >
> > The ZX Spectrum also has the LM1889 (IC14) and pin 13 is indeed used for
> > its s-video mod:
> > http://www.retrowiki.es/fororw/viewtopic.php?f=667&t=29522
> >
> >
> >
> > On Mon, Sep 30, 2013 at 10:18 PM, Luis Antoniosi (CoCoDemus) <
> > retrocanada76 at gmail.com> wrote:
> >
> > > Your answer is on IC39. LM1889: It has several chroma inputs. Need to
> > know
> > > if one of them is useful. I bet on pin 13 Chroma Subcarrier.
> > >
> > >
> > >
> > >
> > > On Mon, Sep 30, 2013 at 3:09 PM, Ken H. <dragon.atv at gmail.com> wrote:
> > >
> > >> Looking at the Tano motherboard I can't see an MC1372
> > >> http://archive.worldofdragon.org/images/4/40/Tano64.png
> > >>
> > >>
> > >>
> > >> On Mon, Sep 30, 2013 at 9:58 PM, Luis Antoniosi (CoCoDemus) <
> > >> retrocanada76 at gmail.com> wrote:
> > >>
> > >>> Is there a chrominance output on it ?
> > >>>
> > >>>
> > >>> On Mon, Sep 30, 2013 at 2:57 PM, Ken H. <dragon.atv at gmail.com>
> wrote:
> > >>>
> > >>>> This is an amazing video quality for the CoCo1 !
> > >>>> Do you think a similar mod could be done with the Tano Dragon?
> > >>>>
> > >>>>
> > >>>> On Mon, Sep 30, 2013 at 5:59 AM, Luis Antoniosi (CoCoDemus) <
> > >>>> retrocanada76 at gmail.com> wrote:
> > >>>>
> > >>>>> With a very simple driver you can make a perfect a s-video output
> > > for
> > >>>> your
> > >>>>> coco1
> > >>>>>
> > >>>>> http://www.youtube.com/watch?v=47r1S8Sjr20
> > >>>>> http://www.youtube.com/watch?v=2AYpUA5H5tg
> > >>>>>
> > >>>>> https://pbs.twimg.com/media/BVYIpfxCEAAy8kO.jpg:large
> > >>>>> https://pbs.twimg.com/media/BVYItw_CQAAQupH.jpg:large
> > >>>>> https://pbs.twimg.com/media/BVYIxdGCcAEMydj.jpg:large
> > >>>>> https://pbs.twimg.com/media/BVYI0ZaCAAAikiF.jpg:large
> > >>>>> https://pbs.twimg.com/media/BVYJEVaCQAAJz1z.jpg:large
> > >>>>> https://pbs.twimg.com/media/BVYJIJQCQAAXWOf.jpg:large
> > >>>>>
> > >>>>> Basicaly s-video signal works with 2 signals: Luminance and
> > >>> chrominance.
> > >>>>> The luminance you can use the same monochrome driver you are used
> > >> to, 2
> > >>>>> transistors tied on Y output from 6847. But the chrominance you get
> > >>> from
> > >>>>> 1347 pin 8. A 300 Ohm resistor is needed to reduce the vertical
> > >> lines.
> > >>> It
> > >>>>> worked with 2 monitors an a s-video / vga converter I have here.
> > >>>>>
> > >>>>> Check the video how to get artifact colors from it.
> > >>>>>
> > >>>>> Didn't test on coco2, dunno if works since the 1372 is connected
> > >>>> different
> > >>>>> there.
> > >>>>>
> > >>>>>
> > >>>>> --
> > >>>>> Long live the CoCo
> > >>>>>
> > >>>>> --
> > >>>>> Coco mailing list
> > >>>>> Coco at maltedmedia.com
> > >>>>> http://five.pairlist.net/mailman/listinfo/coco
> > >>>>
> > >>>> --
> > >>>> Coco mailing list
> > >>>> Coco at maltedmedia.com
> > >>>> http://five.pairlist.net/mailman/listinfo/coco
> > >>>
> > >>>
> > >>>
> > >>> --
> > >>> Long live the CoCo
> > >>>
> > >>> --
> > >>> Coco mailing list
> > >>> Coco at maltedmedia.com
> > >>> http://five.pairlist.net/mailman/listinfo/coco
> > >>
> > >> --
> > >> Coco mailing list
> > >> Coco at maltedmedia.com
> > >> http://five.pairlist.net/mailman/listinfo/coco
> > >
> > >
> > >
> > > --
> > > Long live the CoCo
> > >
> > > --
> > > Coco mailing list
> > > Coco at maltedmedia.com
> > > http://five.pairlist.net/mailman/listinfo/coco
> >
> > --
> > Coco mailing list
> > Coco at maltedmedia.com
> > http://five.pairlist.net/mailman/listinfo/coco
> >
> > --
> > Coco mailing list
> > Coco at maltedmedia.com
> > http://five.pairlist.net/mailman/listinfo/coco
> >
>
> --
> Coco mailing list
> Coco at maltedmedia.com
> http://five.pairlist.net/mailman/listinfo/coco
>

-- 
Long live the CoCo