Converting TTL monitor to Analog

From: Chuck McManis <cmcmanis_at_mcmanis.com>
Date: Wed May 9 14:29:06 2001

>How do you define resolution at the monitor level? I've always been able to
>get entirely different resolutions out of monitors, and why would they
>disagree? If it's an analogue signal, wouldn't the monitor just sweep along
>and project whatever is input?

Color monitors have a color mask, and that color mask has a 'dot pitch'
which defines where you can display pixels. If you attempt to display more
pixels on a line than there are holes in the mask, then you will get
banding artifacts.

Next there is frequency response. The amplifiers that connect to the color
guns have something called a 'slew rate' which is the rate at which they
can change their output color. If you put to many pixels side by side then
you will start seeing color degradation due to the fact that the amplifier
can't get to the new color fast enough. If you display several columns of
vertical white lines on a black background you will see (in cheaper
monitors) that the leading edge of the while line is not white, its gray.
And as you increase the number of lines the white lines will get grayer and
eventually you will have just a gray screen.

You "can" drive monitors all over the map, eventually you will destroy them
if you allow the horizontal output driver to over heat. However, getting an
acceptable signal out of one is more constrained.

--Chuck
Received on Wed May 09 2001 - 14:29:06 BST