لطفا منتظر باشید ...
Publisher19.4 Choosing a Keyboard
Use
the following guidelines when choosing a keyboard:
The position of the primary alphanumeric keys is standard on all
keyboards other than those that use the oddball Dvorak layout. What
varies, sometimes dramatically, is the placement, size, and shape of
other keys, such as the shift keys (Shift, Ctrl, and Alt), the
function keys (which may be arrayed across the top, down the left
side, or both), and the cursor control and numeric keypad keys. If
you are used to a particular layout, purchasing a keyboard with a
similar layout makes it much easier to adapt to the new keyboard.
Keyboards vary both in obvious wayslayout, size, and
formand in subtle wayskey spacing, angle, dishing,
travel, pressure required, and tactile feedback.
People's sensitivity to these differences varies.
Some are keyboard agnostics who can sit down in front of a new
keyboard and, regardless of layout or tactile response, be up to
speed in a few minutes. Others have strong preferences about layout
and feel. If you've never met a keyboard you
didn't like, you can disregard these issues and
choose a keyboard based on other factors. If love and hate are words
you apply to keyboards, use an identical keyboard for at least an
hour before you buy one for yourself.
Some keyboards provide dedicated and/or programmable function keys to
automate such things as firing up your browser or email client or to
allow you to define custom macros that can be invoked with a single
keystroke. These functions are typically not built into the keyboard
itself, but require loading a driver. To take advantage of these
functions, make sure a driver is available for the OS you use.
Although it sounds trivial, the weight of a keyboard can be a
significant issue for some people. The lightest keyboard
we've seen weighed just over 1 lb., and the heaviest
was nearly 8 lbs. If your keyboard stays on your desktop, a heavy
keyboard is less likely to slide around. Conversely, a very heavy
keyboard may be uncomfortable for someone who works with the keyboard
in his lap.
Keyboards are low-margin products. As a means to differentiate their
products and increase margins, some manufacturers produce keyboards
with speakers, scanners, and other entirely unrelated functions built
in. These functions are often clumsy to use, are fragile, and have
limited features. If you want speakers or a scanner, buy speakers or
a scanner. Don't get a keyboard with them built in.
Various manufacturers make wireless keyboards, which are ideal for
presentations and TV-based web browsing. Wireless keyboards include a
separate receiver module that connects to a USB port or the PS/2
keyboard port on the PC. The keyboard and receiver communicate using
either radio frequency (RF) or infrared (IR). IR keyboards require
direct line-of-sight between the keyboard and receiver, while RF
keyboards do not. Most IR keyboards and many RF keyboards provide
very limited rangeas little as 5 feet or so which
limits their utility to working around a desk without cables
tangling. Some RF keyboards and a few IR keyboards use higher power
to provide longer range, up to 50 feet or more. These are often quite
expensive and provide relatively short battery life. Whichever type
of wireless keyboard you get, make sure it uses standard (AA/AAA/9V)
alkaline or NiMH batteries rather than a proprietary NiCd battery
pack, which is subject to the infamous NiCd memory effect whereby
NiCd batteries soon begin to lose the ability to hold a charge.
|
