Re: IGS Monitor from Composite Source?

[mdj <mdj.mdj@gmail.com>]

On May 6, 5:19 pm, "Michael J. Mahon" <mjma...@aol.com> wrote:

> > How so? A composite colour monitor has to decode the composite signal
> > to RGB to display it so I don't see how it would look any worse, other
> > than the higher-fidelity of most RGB displays.
>
> Just because the adapter boxes that cost less than $500 are not
> "Sony quality" chroma demodulators.
>
> Of course, the *big* drop in quality comes from doing the chroma
> separation inherent in composite video, with the consequent bandwidth
> limitation.

That's what I meant...

> >>I don't know if any such box exists. It would be simpler than a
> >>hypothetical "composite to VGA" converter, because it doesn't need to do
> >>a frequency conversion as well.
>
> > There are plenty of chips out there that'll decode NTSC into component
> > forms. I doubt you'd need a lot in the way of support circuitry to
> > drive it.
>
> No, it's a mess.  There are filters and delay lines involved, so any
> chip you find will have lots of pins and lots of external components.
> Chroma separation and demodulation is either an analog process or a
> pretty complex DSP process, so there's no free lunch.

I see. I've not really bothered looking in the gizzards of
contemporary television sets - I just figured that by now the chroma
processing would be a  'black-box' solution.

> > If your intention is to convert Apple II composite to RGB that might
> > be a little trickier, as some modern decoders tend to be confused by
> > the quasi-NTSC nature of the Apple II video signal.
>
> That might be an issue for a "modern" digital/DSP solution--it might
> not lock to the Apple II signal.  An analog solution would not have
> a problem with that.

I figured the majority of (available) integrated solutions would use
this approach.

Matt