Microsoft Office Tutorials and References
In Depth Information
Computer Hardware
clearly. Resolution is easy to adjust on most monitors. Dot pitch measures the distance
between pixels, so a smaller dot pitch means a sharper image. A .28 or .26 dot pitch (dp)
is typical for today’s monitors.
A computer display system consists of a monitor and a graphics card , also called a
video display adapter or video card . A card is a rigid piece of insulating material with cir-
cuits on it. The circuits control the functions of the card. The graphics card is installed
inside the computer on the motherboard, and controls the signals the computer sends to
the monitor. If you plan to display a lot of images on the monitor, you may also need a
graphics accelerator card to speed up the computer’s ability to display them. When pur-
chasing a monitor, you must be sure that it comes with a video card that is compatible
with your computer.
Refer back to the computer ad in Figure 1. Does this personal computer include a
monitor and video card? The correct answer is yes, both are included. What is the type,
size, and resolution of the monitor? The monitor is a 15" 1,024
768 flat panel monitor.
A printer produces a paper copy of the text or graphics processed by the computer. A
printed copy of computer output is called hard copy , because it is more tangible than the
electronic or magnetic copies found on a disk, in the computer memory, or on the moni-
tor. There are three popular categories of printers, and each has special capabilities.
The most popular printers for business use are laser printers , like the one shown on the
left in Figure 11, because they use the same technology as a photocopier. A temporary
laser image is transferred onto paper with a powdery substance called toner . This pro-
duces high-quality output quickly and efficiently. The speed of laser printers is measured
in pages per minute (ppm) . Color laser printers use several toner cartridges to apply color
to the page. Non-color laser printers are less expensive than color laser printers.
A less expensive alternative to the laser printer is to use a color inkjet printer such as
the one shown on the right in Figure 11. These printers spray ink onto paper. The quality
of the inkjet output is almost comparable to a laser printer’s output. Inkjet printers, with
and without color capabilities, are very popular printers for home use. The speed of inkjet
printers is also measured in pages per minute.
Figure 11
Types of printers
Laser Printer
Inkjet Printer
Another type of printer is the dot matrix printer, the oldest printing technology currently
found on the computer market. Dot matrix printers transfer ink to the paper by striking a
ribbon with pins. Using more pins controls the quality of the print, so a 24-pin dot matrix
printer produces better quality print than a 9-pin. Dot matrix printers are most often used
when a large number of pages need to be printed fairly quickly or when a business needs
to print on multi-page continuous forms. The speed of dot matrix printers is measured in
characters per second (cps). Some examples of their usefulness are the printing of grade
reports, bank statements, or payroll checks.
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