Re: Analog NTSC to RGB converter?

[Michael J. Mahon <mjmahon@aol.com>]

Linards Ticmanis <ticmanis@gmx.de> wrote:
> Hello, do you maybe know whether there is such a thing as a purely
> analog NTSC to RGB converter that one could purchase, either as a
> complete device or at least as a kit or a ready-made PCB?
> 
> I found a schematic here:
> 
> http://www.seekic.com/circuit_diagram/A-D_D-A_Converter_Circuit/NTSC_TO_RGB_CONVERTER.html
> 
> but it is pretty complex and I don't know whether this doesn't exceed my
> abilities. I've never laid out (or etched) PCBs myself, and I think this
> schematic is beyond what one would reasonably build on a breadboard.
> Plus, I'm really too lazy to build it.
> 
> The reason I'm asking is that I've recently got a Commodore 1084 monitor
> in very good shape and it is really a great video monitor as such, even
> 80 characters per line text is really legible on it - but it is a PAL
> model and thus useless for NTSC sources such as my Apple. It can sync to
> 60Hz without problems but of course it can't decode NTSC, so it will
> display only black-and-white with the Apple.
> 
> Thanks for any hints.

Such a converter is essentially the same as the video section of any NTSC
monitor (since color CRTs are all RGB). 

TV-inspired integrated circuits have reduced the package count
considerably, but there's still a lot of analog lifting required--such as
the delay line to match the luminance delay to the filtered chrominance
channel. 

I would expect there to be a lot of surplus NTSC-to-RGB decoders available
on eBay--some with professional specs. 

-michael - NadaNet 3.1 and AppleCrate II: http://home.comcast.net/~mjmahon