Re: RGB monitor on a IIc+

[dempson@actrix.gen.nz (David Empson)]

Mitchell Spector <spec@vax2.concordia.ca> wrote:

> In article buggie@pegasus.unm.edu (stephen e buggie) writes...
> 
> >Will teh RGB converter for IIC PLUS also work with IIC?
> 
>     Absolutely, the Video Expansion Port on the Apple IIc Plus
> is identical to the one on the original Apple IIc. There is no
> difference between them.
> 
> >CGA --- that means IBM style color monitors?   With the adaptor, which
> >version gives the sharpest picture:  CGA or RGB (IIgs monitor type)?
> 
>     CGA monitors used digital RGB (which has a limit of displaying
> 64 colors)

Not exactly.  Digital RGB has a colour limit which depends on the
interface.  In the case of CGA, or Apple's digital RGB (as used on the
Apple /// for example), it is 16 colours.T  here are four colour select
lines, each with two states: two to the fourth power is sixteen.

For CGA, the four lines are red, green, blue and intensity.  The Apple
digital RGB monitors use a more complex mapping system, with different
colours produced.

EGA supports 64 colours (two lines for each primary colour).

-- 
David Empson
dempson@actrix.gen.nz
Snail mail: P.O. Box 27-103, Wellington, New Zealand