On Sat, 23 May 2015, Chris Osborn wrote:
On May 23, 2015, at 8:24 AM, Mark J. Blair <nf6x at nf6x.net> wrote:
> In the middle will be some FPGA to perform any necessary magic. I've
> been looking at a prohibitively expensive ($115) one that has enough
> dual-port RAM blocks to support a frame buffer.
Getting an acceptable combination of crisp 80-column text and proper color
aliasing from a converter is decidedly non-trivial. I own one of just
about every commercially available (and hobby) converters and precisely
none of them provides a universal solution. Some give great displays from
an Amiga and suck for anything else. Of my two (pricey) CVP CM-345S
converters, only one provides useable display from an Apple IIGS. My
GBBS-8220 can occasionally be coaxed into giving a solid display from a
Color Computer 3. The list goes on...
Are you on the CoCo mailing list? Have you seen the
RGB2VGA by Luis
Antoniosi (CoCoDemus)? I know at one point he had been tinkering with
making it support composite from the Apple II. It?s semi open-source, I
think there are 2 versions and the latest version is currently all
closed source.
Luis's converter comes the closest to providing usable display from an
Apple II, but (for me at least) only with certain levels FPGA code.
Still, he is putting a huge amount of effort into the project and I have
high hopes this may be a robust one-size-fits-all solution.
If transparent, tweak-free emulation of a classic CRT display were easily
doable, it would have been done by now.
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