[Coco] Coco RGB to SVGA

[Grumpyx]

Roy, add me to the list for a board level.

Thanks,

Malcom

On Sun, Jun 21, 2015 at 11:02 AM, Brian Blake <random.rodder at gmail.com>
wrote:

> Roy,
>
> Put me down for a board level.
>
> ------------------
> www.tandycoco.com
> www.tandycoco.com/forum
> On Jun 20, 2015 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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>