[Coco] VDG weirdness

[John W. Linville]

Yeah, I'm a one-trick pony... ;-)

On Tue, Oct 20, 2015 at 11:21:02AM -0500, Zippster wrote:
> No, just a badly thought out guess…  
> I realized what it probably was right after sending.  :)
> 
> - Ed
> 
> 
> > On Oct 20, 2015, at 11:15 AM, Brian Blake <random.rodder at gmail.com> wrote:
> > 
> > I doubt it's that, it's CoCo 3 and doesn't use artifacts.
> > 
> > Since it's John's post, I'd guess Fahrfall...
> > 
> > Of course if your comment was in jest, I completely missed it... ;)
> > 
> > 
> > 
> > Brian
> > 
> > 
> > On 10/20/2015 11:52 AM, Zippster wrote:
> >> Ooooh…  Nice.   Sock Master’s Donkey Kong, maybe?
> >> 
> >> - Ed
> >> 
> >>> On Oct 20, 2015, at 9:47 AM, John W. Linville <linville at tuxdriver.com> wrote:
> >>> 
> >>> NTSC artifacts are an important consideration, for sure.  FWIW, what
> >>> I had in mind would be to put a certain CoCo game in a traditional
> >>> arcade cabinet (with 15kHz RGB video).  In that case, whether or not
> >>> the NTSC artifacts matter becomes game dependent... :-)
> >>> 
> >>> John
> >>> 
> >>> On Mon, Oct 19, 2015 at 05:53:48PM -0500, Zippster wrote:
> >>>> This is very similar to a board I was developing when Brendan approached me
> >>>> with his FPGA based project, which I stopped development on in favor of pursuing
> >>>> the FPGA solution.
> >>>> 
> >>>> The only major drawback for NTSC machines would be the lack of artifacts for CoCo1/2 games,
> >>>> but an AD725 or similar could be added to generate high quality composite that might
> >>>> get them back on a secondary output.  Of course that doesn’t matter for PAL.
> >>>> 
> >>>> Very nice! :)
> >>>> 
> >>>> - Ed
> >>>> 
> >>>> 
> >>>>> On Oct 19, 2015, at 5:42 PM, Phill Harvey-Smith <afra at ramoth.org.uk> wrote:
> >>>>> 
> >>>>> On 19/10/2015 22:40, John W. Linville wrote:
> >>>>>> That's pretty cool, Phill!  After seeing the old Atom color boards
> >>>>>> I had thought to do a similar project at some point.
> >>>>>> 
> >>>>>> Do you have any plans to market such a board?
> >>>>> Well I'm thinking about it but got a couple of other projects on the go at the mo. And it's kinda still in development because of the PAL / NTSC thing.
> >>>>> 
> >>>>> Basically I'm maybe going to implement the PAL additional line logic in the CPLD so that it just relies on the VDG clock output by the SAM (and disconnects the 6847's VDG clock from any circuitry on the motherboard).
> >>>>> 
> >>>>> This should make it independent of the various different models of both the CoCo and Dragon motherboards, and as a side effect should enable a machine to run at either frame rate (if I get it right).
> >>>>> 
> >>>>> Cheers.
> >>>>> 
> >>>>> Phill.
> >>>>> 
> >>>>> -- 
> >>>>> Phill Harvey-Smith, Programmer, Hardware hacker, and general eccentric !
> >>>>> 
> >>>>> "You can twist perceptions, but reality won't budge" -- Rush.
> >>>>> 
> >>>>> -- 
> >>>>> Coco mailing list
> >>>>> Coco at maltedmedia.com
> >>>>> https://pairlist5.pair.net/mailman/listinfo/coco
> >>>> 
> >>>> -- 
> >>>> Coco mailing list
> >>>> Coco at maltedmedia.com
> >>>> https://pairlist5.pair.net/mailman/listinfo/coco
> >>> -- 
> >>> John W. Linville		Someday the world will need a hero, and you
> >>> linville at tuxdriver.com			might be all we have.  Be ready.
> >>> 
> >>> -- 
> >>> Coco mailing list
> >>> Coco at maltedmedia.com
> >>> https://pairlist5.pair.net/mailman/listinfo/coco
> >> 
> > 
> > 
> > -- 
> > ------------------------------------------------------------------------
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> > Tandy CoCo Forum <http://www.tandycoco.com/forum>
> > 
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> 
> 
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-- 
John W. Linville		Someday the world will need a hero, and you
linville at tuxdriver.com			might be all we have.  Be ready.