[Coco] RGB2VGA on DE0-Nano (improvements)
Gene Heskett
gheskett at wdtv.com
Sat Aug 30 10:20:38 EDT 2014
On Saturday 30 August 2014 08:07:57 Mark McDougall did opine
And Gene did reply:
> On 30/08/2014 8:33 PM, Gene Heskett wrote:
> > any sampling is likely something that would need
> > addressed not by grabbing the RGB output of a software GIME chip or a
> > 6847, but by grabbing the data straight from memory as it is
> > delivered to those chips and generating the VGA completely external
> > to any emulation of the coco's color generating chips.
>
> Which is exactly how the Carte Blanche (Apple II) and MISE (TRS-80
> Model I) do the job. Much easier, much cleaner, and more flexible.
>
> Then you have the F18A for the TI99/4A, an FPGA-based drop-in solution
> that is commercially available for the TI99/4A, which is what Gene
> goes on to dream about! ;)
>
> <http://codehackcreate.com/archives/30>
Interesting. He did that in a 250k gate device, so the rest of the gime
might need a 500k gate device. But it would need the 84 pin square
footprint of the existing gime if it is to be just plugged in. In my
machine, with a 2 meg dram kit in it, expansion real estate for the level
translators needed would be hard to find as nearly all of it would have to
be obtained in a direction toward the keyboard.
But since my next birthday will be the 80th, I don't think I will embark
to duplicate his work and a memory manager too.
> So... not outside the realm of possibility for the Coco!
No its not, but it will take someone with confidence that they have enough
time to complete the project. My recent episode with a pulmonary embolism
has reminded me that none of us have a tomorrow guarantee. Other than my
arthritis/scoliosis pain, I feel better than I have in 10 years. But that
doesn't extend my warranty.
> Regards,
Cheers, Gene Heskett
--
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Genes Web page <http://geneslinuxbox.net:6309/gene>
US V Castleman, SCOTUS, Mar 2014 is grounds for Impeaching SCOTUS
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