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BOOT CAMP 052
MONITORS, PART 2
When you switch on your desktop PC this morning you might
like to thank Karl Braun for making it all possible. He was the Austrian
physicist who in 1897 perfected the cathode ray tube or CRT, upon which the
vast majority of PC monitors (and all manner of visual displays, including most
televisions) are based. It seems slightly ironic that cutting-edge PCs should
be so reliant on a technology that is more than 100 years old, but the CRT is
the most competent and cost-effective display device currently available, but
maybe not for much longer…
The cathode ray tube has served us well but it has many
drawbacks and there is a growing need and desire for change. CRTs are basically
big glass bottles -- with all of the air sucked out -- they are heavy,
mechanically fragile and the boxes that house them take up a disproportionate
amount of desk space. CRTs are not very energy efficient, they waste a lot of
power in the form of heat and they emit potentially harmful high and low
frequency electromagnetic radiation. The maximum size of CRT displays is
limited -- 37-inches is about as big as manufacturers dare go -- so they are
not much use for mass viewing.
So what are the alternatives to that 14 or 15-inch monitor
that came as standard with your PC? If you simply want to increase the size of
your desktop display, and space isn't a major consideration, then CRT monitors
still have plenty to offer, particularly in terms of cost and performance. The
most compelling reason to upgrade to a larger screen is the type of software
that you use. Small screens are fine for text and graphics based programs, like
word processors and accounts packages but increasingly PCs are used for visual
applications, such as desk-top publishing, image processing, CAD/CAM (see
Jargon Filter), playing games and displaying moving video. The next logical
step up in terms of size is 17 or 19-inches and with street prices for 17-inch
models starting at just over £200 it is a relatively modest outlay.
However, screen size is only part of the equation. Other
factors to bear in mind when shopping for a monitor are dot-pitch, resolution
range (see last week's Boot Camp) and additional facilities, like on-board
speakers and microphone plus connection options such as PC/Mac compatibility
and USB interface (see Jargon Filter). Large-screen CRT monitors go up to 20, 21
inches and beyond but they are designed for specialist commercial and
industrial applications, with prices to match (£1,000 plus).
If desk space is limited and cost isn't an overriding factor
then it is worth considering a flat-screen liquid crystal display (LCD)
monitor. LCD panels have been used on portable and laptop PCs for at least the
past ten years but recent improvements in design and production yield have
enabled manufacturers to build larger screens more cheaply. Apart from being
only a couple of inches thick LCD's have a number of other advantages. They
consume between a quarter and a third less power than an equivalent-sized CRT,
radiation levels are minimal and the display does not flicker to anything like
the extent of a conventional picture tube. The downside is price -- current
models cost between three and six times as much as equivalent-sized CRTs -- the
viewing angle is much shallower and they are not as flexible as CRTs when it
comes to displaying moving video or multimedia material.
Nevertheless, for most routine home and commercial
applications 14 to 18 inch LCD monitors have become an increasingly attractive
proposition. Prices are coming down quickly; in fact they have almost halved in
the past eighteen months! Some 15-inch models, which have a screen area
equivalent to a 17-inch CRT, now sell for less than £600. There is every reason
to suppose the price will continue to fall for some time to come as the
economies of scale work their way through.
Serious PC gamers and the growing use of PCs as presentation
tools has created a growing demand for very much larger displays than are
possible using conventional screens. Flat gas plasma screens, which use a fusion
of LCD and CRT technologies are now reaching the shops and available in screen
sizes from 42 to 60 inches. Plasma screens are just a few inches thick and have
a similar viewing angle to CRTs, but image brightness is still not that
wonderful. Most plasma screens have data inputs, so they can be used for PC
display and there are plans for smaller screens, down to 32-inches. However the
cost is likely to be prohibitive for some time to come with 42-inch models
currently selling for between £8,000 and £12,000!
For larger audiences and game fanatics with deep pockets (and
large living rooms…) the solution is a video or data projector; models are
available that can generate images from 50 to 300 inches across. Most video
projectors use high-intensity CRTs (one for each primary colour) or shine a
powerful light through small LCD panels. Projector prices have tumbled in the
past couple of years and you can pick up a modestly equipped tabletop model for
around £1800. Most projectors are about the size of a 35mm slide projector and
can be easily transported from place to place, or suspended from a ceiling. The
only real problem with front projectors is the need to darken the room, and for
best results they need a high-reflectivity screen, which can add several
hundred pounds to the overall cost. Rear projectors, that look like giant TVs
are available with screens from 40 to 60 inches across and again they perform
best in dimly lit rooms; prices start at £2500.
Next week -- disc partitioning and formatting
JARGON FILTER
CAD/CAM
Computer aided design/manufacture -- applications that
require a high performance visual display
DOT PITCH
A measure of the size and spacing of the coloured
light-emitting phosphor dots or stripes that coat the inside of the screen. The
current norm is around 0.28mm, higher performance CRTs have dot pitches of
between 0.23 and 0.25mm
USB
Universal Serial Bus, high-speed industry standard
connection system for peripherals including monitors, modems, joysticks
printers etc., that does away with confusing technicalities and allows 'hot
swaps', allowing connection and disconnection with the PC switched on
TOP TIP
Create your own personal screensaver. If you have the OSR2
release of Windows 95 or Windows 98 click on the Start button go to Settings,
then Control Panel and double click on the Display icon. Select the Screensaver
tab and scroll down the list until you come to '3D Text'. Highlight the entry
and click on the Settings button. You can enter your name or a message -- up to
16 characters and spaces long -- in the text field, that will bounce or wobble
around the screen, or you can choose an animated digital clock display. Click
on the Texture buttons and try some of the *.bmp files in the Windows folder.
This screensaver also contains an 'Easter egg' a hidden novelty feature planted
by the programmers. Type the word 'Volcano' into the text field, click OK and
see what happens…
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