ELEMENTS OF HARDWARE

Output

The two most popular output devices are the printer and the video screen, or monitor. A monitor is required for almost any computer system for two reasons. First, the data or instructions being input from the keyboard or other input device are shown on the monitor. A blinking rectangle or underline called a cursor moves on the screen as the data or instructions are input. Second, the monitor is an almost instantaneous outlet for the result of the processing.

Often a user will view the results of processing on the monitor screen and then decide that hard copy is needed, in the form of a printed page. Such hard copy is useful because the output to the monitor is not permanent. For main­frame users, it is usually very easy to divert the output on the monitor to a page printer at a computer center. A page printer is a high-speed printer that can print an entire page in one motion. For personal computer users, a large number of printers are available today in varying speeds, qualities of print, and price ranges. Other types of printers commonly used with PCs are ink jet printers and laser printers. The ink-jet printer sprays ink on the page to create letters and pictures. The laser printer is much like a copier except that instead of photocopying an existing document, it converts output from a computer into a printed form.

Не нашли, что искали? Воспользуйтесь поиском: