n132  0042  05 Jun 84
BC-COMPUTER-COLUMN
(ScienceTimes)
By ERIK SANDBERG-DIMENT
c.1984 N.Y. Times News Service
    NEW YORK - The one element of computing that seems to generate no
fear is the monitor. To a generation nurtured by television,
electronic images are as familiar as the breakfast cereal often
consumed in front of them. So it comes as a surprise to many people
that a video display, the picture window into the computer, is a
relatively new addition to the machine.
    Before personal computers appeared, no continuous visual display
enlivened the technology of electronic data processing. Programmers
did their thing on paper. When everything was in order, the code
laboriously arrived at was keyed into the computer. The program ran
unseen by human eyes. The same held true for the data used with the
program. It was entered and processed undramatized. Only the final
results were made evident, in printed copy.
    Although the use of a monitor with the modern personal computer does
not make us privy to all the internal workings of the machine, it has
accustomed us to being able to watch at least a semblance of what is
going on. Perhaps it is this taking of the display for granted;
perhaps it is that most people do not yet conceive of purchasing a
computer as a component system, as they do a stereo; perhaps it is
simply a matter of taking the easy way out; but when it comes to
acquiring a computer monitor, most people do very little looking
around. This is a mistake.
    One has more contact with the monitor than with any other part of
the computer, including the keyboard. So, for comfort's sake if for
no other, a good monitor is essential, so much so that even computers
like Compaq or Kaypro, which come with their own diminutive built-in
monitors, are candidates for a supplementary screen. The question is,
what constitutes a good monitor?
    There is no straightforward answer because personal perception,
which at best is less than consistent, is unavoidably involved.
However, there are some basic rules one can follow.
    First, the monitor must be compatible with the computer. This
usually presents no major problem. For example, an IBM PC, suitably
equipped, can drive, or use, any one of the three major types of
cathode ray tube (CRT) monitors: monochrome, composite color and RGB
color.
    In choosing among the many CRT monitors available today, one must
weigh carefully the question of color. Even in the case of a
monochrome unit, color is an important consideration. Currently, a
monitor that displays white characters on a black background is
deemed the least desirable, with green or amber being the hue of
choice.
    Amber is a hot concept this year, but not everyone finds it more
restful than green. The qualities that really count on screen are
resolution, contrast and the absence of flicker, though not
necessarily in that order.
    I am very adversely affected by flicker; thus I rate it as the most
important factor. Others are willing to overlook a certain amount of
flicker if it means having increased sharpness. The final test for
any screen, be it green, amber or full color, is whether your eyes
are comfortable with it over a long period of time.
    The difference between composite color and RGB (red, green, blue)
monitors is more clear-cut than the variations among monochrome
types, and it is defined by the technology involved. Monitors using
the RGB format always produce a sharper image because each of the
three colors is brought to the display as an independent signal.
Composite color, as its name implies, utilizes a single, compound
signal, which is split by means of three electron-beam guns inside
the cathode ray tube.
    While RGB color is sharper than composite color, it is not as sharp
as monochrome. Because of this, some people buy two monitors, a
monochrome for such tasks as word processing and a color monitor for
graphics endeavors.
    This double expenditure might seem a little excessive, but the fact
is that using a color monitor for a lot of word processing almost
inevitably leads to eye strain, whereas a monochrome monitor
naturally cannot display the color graphics used in charting or, for
that matter, games and other entertainment programs.
    Whichever type of display you decide will meet the majority of your
needs, the only way to choose among the various models on the market
is through a side-by-side comparison of the leading contenders. Have
the dealer run a couple of programs containing both text and
graphics. Compare the results.
    First, check the sharpness of the text characters. Pay particular
attention to those appearing at the edges of the screen; there can be
quite a difference between the center of an image and its
peripheries. Look closely for flickers and wavers, especially when
text is being scrolled or the screen changed.
    Next, compare the degree of jaggedness in the curved lines and
circles of the graphics displays. Also watch for color bleeds or
shadows. Vary the contrast, tint and color so you can see what range
of adjustment is possible. Then step back and look at the picture
from different angles to check how much glare the screen produces
under different light conditions.
    Finally, once your eyes have given the go-ahead, but before you
plunk down the cash, remember to match the monitor to the computer.
Buying a top-of-the-line display for an inexpensive computer will not
get you the great picture you were expecting. A low-end computer
simply cannot produce the high-quality signal a first-class monitor
needs in order to give its all.
    
nyt-06-05-84 0339edt
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