Re: How does the apple2 RGB card work?

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

Michael J. Mahon wrote:

> Presumeably only the attenuation is required, and the zener is just to
> prevent overloads?  With a 5:1 attenuation required, any DC level shift
> would be very easy just with resistors.

> I had expected some matrixing of the RGB signals to produce "Apple"
> colors instead of RGBI colors.

I've not seen the actual monitor myself, I don't think they were ever
available for sale in Australia, probably owing to issues with 50hz
IIe's and RGB output...

A copy of the circuit is in *one* of the manuals... I'm not sure
whether it's the AppleColour RGB Card manual, Apple III manual, etc.
Since you've actually got one, I'd recommend just having a look....

> You also mentioned that there is a *switch* inside the monitor that
> bypasses the digital conversion, making it an analog RGB display...?
> (Getting screwdriver...)

If memory serves, yes.