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Unformatted text preview: devices through which data is recorded on
some media (such as floppies or tapes) and then entered into the computer later. Since
the speed with which a human being can enter data is very less as compared to the data
processing speed of a computer, when data entry is done offline, it saves the precious
computer time. The commonly used offline data entry devices are key-to-tape, key-tofloppy and key-to-disk.
19. Computer output generated by output devices are of two types - soft-copy output and
hard-copy output. Soft-copy outputs are temporary in nature and vanish after use. Hardcopy outputs are permanent in nature and can be kept in paper files or can be looked at a
later time when the person is not using the computer. 20. Monitors are by far the most popular output device used today for producing softcopy output. They display the generated output on a television like screen.
21. A monitor and a keyboard are usually associated together to form a video display
terminal (VDT), which is often referred to as just terminal. A terminal serves as both an
input and an output device and is the most popular input/output (I/O) device used with
22. Printers are the most commonly used output devices today for producing hard-copy
output. Based on the printing technology used, printers are classified as dot-matrix
printers, inkjet printers, drum printers, chain/band printers and laser printers. According
to the approach of printing used, printers are classified as impact printers and non-impact
23. Dot-matrix printers are character printers that form characters and all kinds of images
as a pattern of dots.
24. InkJet printers are character printers that form characters and all kinds of images by
spraying small drops of ink on to the paper.
25. Drum printers are line printers that print characters by striking a set of hammers on an
inked ribbon and paper placed against a solid cylindrical drum with characters embossed
on its surface in the form of circular bands.
26. Chain/band printers are line printers that print characters by striking a set of hammers
on an inked ribbon and pap...
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This document was uploaded on 04/07/2014.
- Spring '14