[Coco] Coco RGB to SVGA

[John B]

Thanks Roy.  I will stay tuned for progress.

On Sat, Jun 20, 2015 at 4:40 PM, Roy Justus via Coco <coco at maltedmedia.com>
wrote:

> When I get up to speed I can make 3 per week
>
> Roy Justus
> rjrtty at aol.com
>
>
> -----Original Message-----
> From: John B <trymyz at gmail.com>
> To: CoCoList for Color Computer Enthusiasts <coco at maltedmedia.com>
> Sent: Sat, Jun 20, 2015 4:36 pm
> Subject: Re: [Coco] Coco RGB to SVGA
>
>
> Roy,
>
> Great news.  Put me on the list for one with an enclosure.  How long
> do
> they take to produce?
>
> Thanks,
>
> John
>
> On Sat, Jun 20, 2015 at 4:30 PM, Roy
> Justus via Coco <coco at maltedmedia.com>
> wrote:
>
> > Dear coco friends,
> >
> >
> >
> I have nearly recovered   from illness and loss of my data files
> > so I am
> getting ready to restart production of my converter.
> >
> >       I also  want to
> discuss some aspects of the process of conversion
> > of Coco RGB.     First is
> the noise some see with early version of my
> > converter.   Most common is the
> vertical bands seen during use.
> > Another is the distortion seen with some
> foreground/backround
> > when viewing 80 column text.   Typically the blue in a
> cls(7) backround
> > in SECB.   At first I tried to eliminate this noise  but had
> little
> > success doing it.
> >
> >      The basic problem is this noise comes out of
> the GIME chip and
> > not from any outside source.    The reason it didn't show up
> in the old
> > 15 khz CRT displays is that they naturally filtered the signal due
> to thier
> > low bandwidth response.
> >
> >     The second problem is that my earlier
> converters and other commercially
> > availible units have a hard time keeping an
> LCD display locked.    LCD's
> > have
> > such highbandwith the noise coming out of
> the GIME confuses them and they
> > shut down.
> >
> >     If you want to use a
> converter that won't sync to an LCD try it on a
> > older CRT SVGA
> > display.
> This applys to my old units and commercially availible ones.
> >
> >     To  address
> these problems I have lowered the bandwith of my converter
> > with
> > some low
> pass filtering on both the data lines and sync inputs.    I have
> > also
> changed
> > the PLL tank circuit values to address the phase lock problems.   I
> have
> > tried my
> > new converter on no less than five "picky" LCD's and they stay
> on and
> > sharp.
> >
> >      Another problem is the price of my converter.      It
> cost
> > approximately $100 per
> > unit to build but I think that is way too high.
> I  am going to offer a
> > board level
> > unit for $40  and  a unit with enclosure
> for $60.   I don't do this to
> > make money.
> > i do it because monitors for the
> Coco3 are becoming very rare and I enjoy
> > it.
> >
> >    So let's light up the
> summer with coco3 displays and send me your
> > order for one.    A board level
> unit comes with all the connections for
> > a great repak project and the unit in
> with enclosure looks good on the
> > shelf with the coco3.
> >
> >
> >
> > Roy Justus
> >
> rjrtty at aol.com
> >
> >
> > --
> > Coco mailing list
> > Coco at maltedmedia.com
> >
> https://pairlist5.pair.net/mailman/listinfo/coco
> >
>
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