Re: Apple ][ to VGA monitor adapter board - looking for best color decoding method

[ferdimh@gmx.de]

>
> Since an Apple RGB display (except for SHR) is a bit of a "freak"
> (since it attempts to represent NTSC artifact colors as if they were
> continuous color signals), you will have to make some compromise.
>
> Either you go for crispness and conformity to the normal "RGB card"
> experience, or you go for fidelity to the usual NTSC display.
> Although
> the latter does better justice to most existing Apple II graphics, the
> former is the usualy route, and is less complex.
>
I've got a mechanism which is in between. Colors are nearly perfect,
because they are generated in a fairly semi-analog way.
And I just have some sort of "low chroma bandwidth" emulation.
After studying the //e's PAL circuit I consider it slightly inferior
to mine - though it has a lower component count.

> In an ideal world, it would be possible for the user to select NTSC
> emulation or RGB card emulation, but that may be asking too much.
>
> Sinplicity and crisp, clean 80-column displays argue strongly for
> the RGB card emulation if a choice must be made.  And at least
> the weird treatment that RGB cards provide to many Apple graphics
> is  "familiar".  ;-)
>
I'm going to add some configuration options anyway. I now have 5 modes
for (D)HIRES:

monochrome
colored blocks
colored blocks w/low chroma bandwidth
colored dots
colored dots w/low chroma bandwidth

LORES looks best in colored blocks, and TEXT should REALLY be
monochrome...
So I need to add circuitry watching the HIRES/LORES switch, and some
softswitches in the C0FX range. (card needs to be in slot 7)

BTW: my email address is valid.

Ferdinand