PC Hardware A Beginner’s Guide

(^408) PC Hardware: A Beginner’s Guide
which would roughly translate to 6,600 characters per second. Dot matrix printers can
printupto500cps,inkjetprintersprintfrom2to10ppm,andlaserprintersrangebetween
4 to 20ppm. To draw some correlation between these different ratings, a laser printer that
has a print speed of 6ppm prints at the equivalent speed of around 40cps—but at letter
quality, remember.
Impact versus Nonimpact
Dot matrix, daisy wheel, and line printers actually make contact with the paper when
they print. Each of these printers uses some form of a striking mechanism to bang an
inked ribbon into the paper to create all or a portion of a character or graphic (the daisy
wheel printer can only produce text and special characters). These printers are classified
as impact printers. Impact printers are typically slower and noisier but are better for con-
tinuous and multipart forms.
The opposite of an impact printer is a nonimpact printer, which by definition does not
use a striking mechanism to create the printed document. Nonimpact printers, such as
inkjet, thermal, and laser printers, use other methods to produce a document.
Text and Graphics
Some printers, particularly daisy wheel and line printers, can only print letters, numbers,
and special characters. Because their character sets are cast on the arms of the daisy wheel
or the print chains of the line printer, they do not have the flexibility to produce the vec-
tors needed to create a graphic.
Special printers, called plotters, use a combination of inkjet technology and thex-yco-
ordinates of the drawing elements to create drawings for use in engineering and other
technical areas. Laser printers, inkjets, and many dot matrix printers are capable of merg-
ing text and graphics into a single document.
Figure 17-5. Examples of draft, NLQ, and letter quality print types