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Monitors
Monitors are an important, and widely ignored, component of
the PC. Often a vendor will toss whatever monitor he has
lying around in with your purchase, regardless of its
quality, its compatibility with your system, or your own
needs and preferences.
You need to insist on the best
monitor you can get for your dollar (and better doesn't
necessarily mean bigger). Color monitors rely on color CRTs,
which use three electron guns to fire three streams of
electrons in a beam that will hit a three-dot or
three-stripe pattern on the face (hence the terms dot
pitch and stripe pitch). Electromagnets force the
electron beams to sweep across the display one line of
pixels (picture elements) at a time. At the typical
resolution of 1,024 by 768, for instance, each line contains
1,024 pixels, and there are 768 lines which must be drawn
each time by the electron guns. The electron guns are one
source of fuzzy displays; the larger the screen, the more
fuzzy the display at the edges of the screen. Cyber types
call this astigmatism, same as what causes me to wear
glasses with such thick lens edges. The electrons hit the
phosphor compound on the monitor display, causing it to
glow. The compound glows for varying periods of time and in
varying color patterns, giving you the picture that you see
on your monitor. Right now your monitor is showing you a
mostly white background with black letter-shaped squiggles.
When you get sick of this page and plug in Quake,
your monitor will work much harder to show you the beasties
and backgrounds of that program.
The
color CRT contains three different phosphor compounds: red,
green, and blue. Different colors are created by the
electrons striking the three compounds in different ways.
The three compounds are arranged on the screen in three-dot
patterns (the stripes consist of three lines of red, green,
and blue). Each three-dot, or three-stripe, pattern is
called a pixel. The space between dots of the same color is
known as the dot pitch; with stripes, it is called the
stripe pitch. Monitors come in three types: those using dots
(shadow-mask, flat-square, or dot trio), those using stripes
(aperture-grille), and a cross between the two (slot-mask).
Sony Trinitrons are aperture-grill CRTs, and NEC CromaClears
are slot-masks, along with some Panasonics. Most others,
particularly the more affordable models, are shadow-masks.
Do you care? Not enough to make one type a necessity. The
cyber wonks will argue one type over another, but the rest
of us can't tell enough of a difference to make buying one
kind over another a sticking point when negotiating for a
good deal. (Note: a few users find the horizontal wires used
in an aperture-grill CRT both visible and annoying. Check
one out before you buy one, as you may be one of the
discerning - or picky - few.) You will also hear a lot of
static about the dot pitch, or DP, or the stripe pitch.
Shadow-mask CRTs measure their size in DP, while
aperture-grille CRTs measure theirs in SP. They cannot be
directly compared. A rule of thumb is that an SP CRT will
have a slightly lower number than a comparable DP CRT; for
example, an 0.28mm DP is considered roughly equal to a
0.25mm SP CRT. Don't let the salesman blow smoke up you
about this one. A good monitor has a dot pitch of around
0.28mm, but a slightly higher number isn't a reason to quit
considering the monitor. Dot pitch is only one
consideration.
And
what the dickens is "refresh rate?" It is the rate that a
monitor redraws the screen (watch a video of a functioning
monitor to see the screen refreshing itself; thankfully it
doesn't look like that to the naked eye). A refresh rate of
85 Hz is virtually flicker-free to the most discerning eye,
but a rate as low as 72 Hz is perfectly acceptable for most
of us. (Most TVs have a refresh rate of about 30 Hz; no
monitor has a rate below 60 Hz.) And a too-high refresh rate
can degrade image quality. You can experiment with different
refresh settings; keep your eye just above or to the side of
your screen, and lower the refresh rate until any
perceptible flicker you can detect out of the corner of your
eye is gone. How to change the refresh rate? In most flavors
of Windows, right-click the desktop, choose Properties,
Settings, and click on the advanced button. Under the
Adapter tab, you'll see a list of available refresh rates.
Choose the highest one that you can get away with (you may
have to experiment). In XP, go through Display Properties
and choose Settings, Advanced, Adapter, and List All Modes.
Some
people find themselves with flickering monitors that induce
migraines; they go in to increase their refresh rate, but
their only option is 60 Hz. Not good. What's happened is
that Windows has lost track of the monitor's Plug and Play
configuration, and is using the 60 Hz default as a safety
measure (since a too-high refresh rate can damage the
monitor). Fortunately, this is an easy fix: just go back
into the Properties, Settings, Advanced menu as listed in
the tip above, and choose Monitor. Check the "Automatically
detect Plug & Play monitors" box, and reboot. If this
doesn't work, you'll need to click the Change button and
reinstall the monitor. If this doesn't work, your
monitor may not be set to support anything higher than 60 Hz
under the current resolution rate; lower the screen
resolution and recheck the refresh rates to see if you're
offered anything better.
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