8-bit Computer TV Channel Use

Steven Hirsch snhirsch at gmail.com
Sat May 23 12:28:39 CDT 2015

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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