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Unformatted text preview: ored in a buffer is compared with the data in the
tape/floppy by reading the data from the tape/floppy. If4he two data do not agree, an
audible and visual signal alerts the operator. The operator verifies the correctness of the
field in error with the source document and re-enters the correct data if necessary which
replaces the incorrect data on the tape/floppy.
Key-to-disk devices are used as data recording stations in systems where data from
different points have to be recorded for processing at one point. Typically, from 8 to 64
keyboard stations are linked to a small special-purpose computer to record source data on
a disk. Each station has a keyboard and a display monitor. Information entered via the keyboard is displayed on the monitor's screen to allow a visual check. The small specialpurpose computer is required to control the input from the various stations, enabling the
data to be held temporarily for verification and editing before allocation to the disk
storage. Thus, these data entry systems are able to correct data before storing it on a
magnetic disk and before its entry into the main computer system.
An output device is an electromechanical device that accepts data from a computer and
translates them into a form suitable for use by the outside world (the users). A wide range
of output devices is available today that can be broadly classified into the following
4. Computer output microfilm
5. Screen image projector
6. Voice response systems
The various types of output devices along with their typical applications are described
Output devices generate computer output, which can be broadly classified into the
following two types:
1. Soft-copy output. A soft-copy output is an output, which is not produced on a paper or
some material that can be touched and carried for being shown to others. They are
temporary in nature and vanish after use. For example, output displayed on a terminal
screen or spoken out by...
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This document was uploaded on 04/07/2014.
- Spring '14