RGB-VGA Converter -- buy or build?
ard at p850ug1.demon.co.uk
Sun Mar 14 16:29:03 CDT 2010
> As previously discussed in this list, and documented on
> http://www.oldskool.org/pc/cgacal , CGA monitors have circuitry to
> change color index #6 to a different color. CGA also has a fourth
> "intensity" pin. Does anyone know if some sort of specially-wired cable
> might be able to convert 4-pin RGBI to something these kinds of
> converters can take as input and everything will still look decently?
It's goign to take more than a cable. THere must be components involved.
> I ask because I have a need to do video capture of native CGA output.
> Don't ask :-)
If this is a real CGA card, there is most likely an NTSC-compatible
composoite colour output available too. It may be on an RCA phono socket
on the bracket (IBM had that), a header inside, or sometimes on pin 7
(otherwise unused) of the DE9 socket.
You might look at the IBM CGA card scheamtics. They include the circuit
to encode the RGBI signals to NTSC composite video.
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