Re: Why not color?

[mjmahon@aol.com (Michael J. Mahon)]

Derek E. wrote:

>My memory may be foggy on this, but weren't a lot of Double High Res
>programs in black and white?  Programs such as: MouseDesk (aka Apple
>II Desktop), MouseCalc, MultiScribe (aka BeagleWrite), etc.  Why
>didn't these use color?  Is Double High Res like Single High Res in
>that the colors bleed and so you get better "effective" resolution by
>not using color?

That's it exactly.

When DHR is used in color, 4 "monochrome" pixels show up as a
single "color pixel".  Much better horizontal resolution is available
if the screen is treated as monochrome.

If a single-pixel object (like the tip of a mouse pointer) is moved
across the DHR screen, the mono display will show it clearly.
If the display is interpreted as color, then the single pixel will
still have sharp luminance (unless luminance bandwidth is
limited, as it is for a composite video signal), but the dot will
be rendered as a several-pixel smear of color that changes as
the dot moves horizontally.

On a high-bandwidth RGB display, the dot should remain
relatively sharp, but its color will rotate through four different
hues of relatively low brightness as the dot moves horizontally,
which is not very useful in a desktop rendering.

-michael

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