Re: Supercard

[bieling@terra.es (Jorge ChB)]

Linards Ticmanis <ticmanis@gmx.de> wrote:

> Jorge ChB wrote:
> 
> > , windowed pixels
> > that span 4 bits among consecutive 7 bits "bytes" that happen to
> > alternate between main and aux memory banks
> 
> I'd just like to add that these don't exist as such. Bits
> 113-114-115-116 on a line are no more (or less) of a pixel than bits
> 114-115-116-117 or bits 115-116-117-118.

Linards, I'm not so sure...

I believe that the "pixels" shouldn't be sitting across the boundaries
of a single cycle of the color reference unless you want odd things to
start happening. For example, that the color of your "pixel" becomes a
function of the colors of the adjacent "pixels", an odd behavior for a
(color) "picture element"... and the reason why the "pixels" should in
this particular case (Apple II DHGR) better be conceptually grouped by 4
and starting from the first bit, not from the 2nd nor the 3rd nor the
4th.

The RGB video output generated by a IIgs may well be against your theory
too : I bet that the patterns below won't show on the screen a single
white "pixel" moving from left to right, as would be the case if any 4
bits could be a single pixel:

1.- 11110000 -> 1 pixel, white
2.- 01111000 -> 2 pixels, 1st yellow, 2nd dark blue
3.- 00111100 -> 2 pixels, 1st orange, 2nd medium blue
4.- 00011110 -> 2 pixels, 1st magenta, 2nd aqua
5.- 00001111 -> 1 pixel, white

Instead you'll get a single white pixel for patterns 1&5, and *two*
adjacent pixels for patterns 2,3 and 4, of varying colors.

?
-- 
Jorge Chamorro Bieling