Re: double lowres funkiness

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

Dennis Jenkins <dennis@uranium.usb.com> wrote:

>       Anyway, does anyone know why the IIe card and IIgs would implement
> double lowres graphics differently?  Mr. Empson? :)

I hardly ever used double lo-res, but I don't remember it behaving oddly
on the IIgs.  I probably never used it by poking data directly into
screen memory.

Have you tried using Applesoft's built-in support (on the IIgs only) for
double lo-res graphics?  Does it exhibit strange colour effects?  If
not, is it modifying the values written into main memory to compensate
for the behaviour you observed?

Have you checked the behaviour on the composite output?  The behaviour
you observe might be a design fault in the VGC.

I can't easily test any of this myself, as I don't have a IIgs system
set up any more.