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Beginners
How To Guide
The Basics of Information Technology
Hardware
Hardware
can be defined as IT-related machinery and equipment
- if you can fall over it, its hardware! This would
include physical machines such as personal computers
(PC's), storage devices (such as CD's) and cables etc.
In order to operate however, a computer uses software
- hardware and software are interdependent. Hardware
is the physical unit which stores and transmits information,
software is the logic and language that dictates how
this is done (see Software below). Until the late 1970's,
most word processors were dedicated machines e.g. typewriters
. Now computers have replaced almost all dedicated word
processors. However in order to be able to work with
text, a PC, which is hardware, requires a set of instructions,
which is software that provides word processing functions
on the PC.. Popular word processing software packages
are Microsoft Word and WordPerfect.
The amount of work that a computer can do is dependent
on the size of its memory and the speed that it can
operate at.
When you see an advertisement for computers, RAM is
often mentioned. This means Random Access Memory and
defines the computers capacity for work. Memory is like
an electronic checkerboard, with each square holding
one byte of data or instruction. When personal computers
first came on the market in the late 1970s, 64 kilobytes
(64 KB) of RAM was the upper limit. Today, 64 megabytes
(64 MB) of RAM is entry level (the starting point) for
a desktop computer i.e. a thousand times as much.
The speed at which a computer operates is dictated by
the Processor in the Central Processing Unit (CPU),
which is the processing part of the computer. The CPU,
clock and main memory make up a the basic computer.
A complete computer system needs other elements such
as the control units, input devices (e.g. keyboard),
output devices (e.g. screen), storage devices and an
operating system (the master control program that runs
the computer). Any hardware device connected to a computer,
such as a monitor, keyboard, printer, disk, tape, graphics
tablet, scanner, joy stick, mouse etc. is know as a
peripheral device.
The Operating System (O/S) is the first program (set
of instructions) to come to life when the computer is
switched on. Its main part, the "kernel,"
is kept in the memory at all times. The operating system
is the link between the hardware and the application
programs that run in the computer. The applications
"talk to" the operating system for all user
activity and file management operations.
Operating Systems that you have probably heard of include
the various versions of Windows (95, 98, NT, XP etc.),
the Unix versions (Solaris, Linux, etc.), the Macintosh
OS, the AS/400's and of course there are many more.
Anyone remember DOS - with its tiny text on a dark screen?
DOS is still used as an Operating System for some applications.
There are other special-purpose operating systems.
Storage devices are the temporary or permanent holding
place for digital information. It refers to disks and
tapes, for example where information is stored - think
of it as having extra physical space in a warehouse.
Memory is not a storage device - it is a temporary workspace
that the computer uses to execute tasks, such as processing
information.
Hardware requirements depend on the size of the databases
that will be created and the number of users or applications
that will be served at the same time. How much? How
fast?
One clear trend in hardware development is the move
towards portability. Portable PC's such as laptops and
notepads (different suppliers label portable PC's in
different ways) are becoming more popular. The advantages
of portable PC's are many - business people can work
from home, the airport or at any workstation in the
office without the need for a fixed location. This can
improve productivity and even reduce office overheads
as the need for fixed workstations diminishes. Portable
PC's also facilitate Internet access from remote locations
giving access to information regardless of where the
user is situated (as long as an Internet connection
can be established in that location) is also makes it
easier for the employee and can reduce overheads
However portable PCs are more expensive - in some cases
significantly so - than Desktops. Also where there is
no power source, the user is dependent on the life of
the battery, which can be limited, typically for 1.5
to 2 hours and possibly less depending on the age of
your machine, the model etc..
Another growing trend in hardware is the development
of various other small portable devices which have much
of the power of a computer, are connected by radio links
to the Internet but are generally smaller and are used
by service engineers, sales people, truck drivers etc.
These are called Personal Digital Assistants (PDAs).
iPAC and PalmPilot are well known brands in this marketplace
- the line between these devices and mobile phones is
slowly blurring over time.
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