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Evaluate a range of input and output devices;
Keyboard- input device that many users will be familiar with, most
common for entering text and numerical.
Works: Key pressed - electronic signal sent to processor which interprets
the signal. SW then takes appropriate action, e.g. making a letter appear
Advantage: Disadvantage:
·Can input text and numbers ·Slow and errors prone
·Supplied with comp, no extra cost ·Difficult to use through paralysis or
·Specialised keyboards available muscular disorder
Concept keyboards- Flat board with grid of programmable keys on its
surface. Used: p.schools/fast food outlets/supermarkets/ppl with disability
Advantage: Disadvantage:
·Less tiring to use, Faster ·People have to get used to them
·Pictures independent of language ·Poor text and numeric input
·Water and dirt resistant surface
Alternative keyboards- designed around form of human body. Split,
alternative key positions.…read more

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Mouse- Pointing device. Consists of a small body than fits palm of hand,
requires flat surface. By moving mouse around surface user can direct a
pointer or cursor on computer screen.
Advantage: Disadvantage:
·Easy to operate ·Flat surface needed beside comp
·Supplied with comp, no extra cost ·Limited set of operations can be
·No skills needed carried out
·Not easily used with laptops
Smart Cards- Plastic card with small embedded computer chip. Can be
programmed to perform tasks and store, info instead of swiping you plug it
into a reader. Overcomes magnetic stripe weaknesses.
Advantage: Disadvantage:
·Can store millions of characters of ·SC readers are expensive and not
data rather than 200 limit of MS available everywhere
·More reliable as not damaged easily
·Data is encrypted, difficult to forge…read more

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Bar Code - Bar codes represent a binary number as a series of thick and
thin block lines. Contain: county of origin, name of manufacture and product
Data is captured by shinning the light from a `wand' or bar code scanner
onto the barcode. Light is reflected differently by lines than gaps, and thus
light is reflected by photoelectric cells to produce an electrical signal. Signal
is decoded by the scanner to produce a no. which is transmitted to a
computer where it may be used for further processing
Advantage: Disadvantage:
·Quick to create ·Cant be read if badly torn
·Durable in rough environments
Touch Screen- allows users to interact with a computer by touching icons
or menu options on the display.
Advantage: Disadvantage:
·Require no previous experience or ·Expensive
training ·Not suitable for use over long
·Preferable to a keyboard and mouse periods- significant pressure required
in public place and non flexible screen can stress
·Easy to clean finger
·Less likely to be stolen or damaged…read more

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OMR- Optical Mark Recognition
A special document/form is used to collect the data. This has specific
boxes representing the user's answers. The user shades in using a HB
pencil. The document is scanned using light, reflected light is analysed and
the positions of the user's answers determined against a template.
Advantage: Disadvantage:
·Human error is eliminated. ·OMR systems are expensive, cost of
·The answers can be read at electronic specialist hw and omr special sheets
speeds reducing processing time · Crumpled forms need to be entered
MICR- Magnetic ink character recognition
Character recognition system- uses special magnetised ink that contains
iron particles. Read by a magnet ink character reader. Will only recognise
numbers in a standard font using the magnetic ink. Ink cant be altered and
any normal ink wrote over the top will be ignored. Used to print details on
cheques to enable fast processing .
Advantage: Disadvantage:
·Fast and minimises human error ·Cant read amount on a cheque-
·Difficult to forge- special ink is difficult room for human error
to reproduce accurately ·Cheques in decline as many stores
·Characters can be read, even if don't accept them
cheque crumpled, dirty or smudged…read more

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ATM- automatic teller machine
Use monochrome CRT screens for displaying info. Screens often become
burnt with blank logo so use cheap flat screen…read more

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