Re: RGB Card Question

[bieling@terra.es (Jorge ChB)]

mdj <mdj.mdj@gmail.com> wrote:

> Bryan Parkoff wrote:
> 
> >     Are you saying that Apple //c's RGB adapter is not the same as Apple
> > //e's RGB card?  What do you mean impossible to use modes?  Modes are like
> > $C05E and $C05F for color / monochrome on DHGR and HGR.
> 
> That's exactly it - AN3 is not available on the IIc video port.
> Different DHIRES modes are selected by toggling 80COL (which is
> available) and AN3 in different orders. This is the only signally
> difference between the IIc Video out and the IIe AUX connector, but
> it's a big one
> 
> It's possible, I suppose, that the IIc adaptor could figure out the
> mode from the sequence of SET80 on off switching, but I'm doubtful of
> this until I actually see it.
> 
> Matt

You can tell if a line has to be interpreted as color/B&W on a line by
line basis by watching for the presence of the color burst at the
beginning of *each* line...
-- 
Jorge Chamorro Bieling