Re: Odd //c monitor

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

Roy replied:

>Michael J. Mahon wrote:

<snip>

>> BTW, the limiting bandwidth may not be achieved if the display
>> is overdriven (contrast too high).  The proper way to adjust a
>> monochrome display is to turn the brightness control up until
>> just below the point where the black parts of the raster begin to
>> be visible, then turn the contrast up to the lowest setting that
>> produces acceptable "brightness" in the white areas.  This
>> ensures that the video amplifier is not overdriven.
>> 
>
>I've been amazed many times when I've seen composite screens where 
>people have turn up the brightness to the point that the (oh snot! now I 
>can't remember the term!) ... diagonal scan lines are visible, so you 
>have a "college rep tie" laid over the screen. Almost every Apple 
>monochrome monitor I've ever gotten was like that, and even at the Post 
>Office, when they were using 5" UniSys monochrome monitors so you could 
>see the exchange, were turned up that high!

Yes, some people think "brighter is better", even when the
information they're trying to see doesn't get any brighter.  ;-)

When TV sets were still a "new thing", it was quite common
to see the retrace lines (there you go ;-) in the background
because the brightness was too high.  Adjusting until they
were no longer visible was a standard practice.

TV standards even set the blanking level a little lower than the
black level (the "setup") so that there's some margin to have
the brightness set a little too high.

In the 60's it became standard for TVs and monitors to generate
their own blanking signal, making the setup unnecessary and
making the pattern of retrace lines invisible under almost all
conditions.

-michael

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