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e\L-lovely-eng\comm1-1.pmd IInd 16-9-11 IIIrd 27-12-11 IVth 4-1-12

Unit 1: Introduction to Computers

1.2 Hardware
Notes
The hardware are the parts of the computer itself including the Central Processing Unit (CPU) and
related microchips and micro-circuitry, keyboards,monitors, case and drives (hard, CD, DVD,
floppy, optical, tape, etc...). Other extra parts called peripheral components or devices include mouse,
printers, modems, scanners, digital cameras and cards (sound, colour, video) etc... Together they
are often referred to as a personal computer.
Central Processing Unit-Though the term relates to a specific chip or the processor a CPU’s
performance is determined by the rest of the computer’s circuitry and chips.
Currently the Pentium chip or processor, made by Intel, is the most common CPU though there are
many other companies that produce processors for personal computers. Examples are the CPU
made by Motorola and AMD.

Figure 1.1

With faster processors the clock speed becomes more important. Compared to some of the first
computers which operated at below 30 megahertz (MHz) the Pentium chips began at 75 MHz in the
late 1990’s. Speeds now exceed 3000+ MHz or 3 gigahertz (GHz) and different chip manufacturers
use different measuring standards (check your local computer store for the latest speed). It depends
on the circuit board that the chip is housed in, or the motherboard, as to whether you are able to
upgrade to a faster chip. The motherboard contains the circuitry and connections that allow the
various component to communicate with each other.
Though there were many computers using many different processors previous to this I call the
80286 processor the advent of home computers as these were the processors that made computers
available for the average person. Using a processor before the 286 involved learning a proprietary
system and software. Most new software are being developed for the newest and fastest processors
so it can be difficult to use an older computer system.
Keyboard: The keyboard is used to type information into the computer or input information. There
are many different keyboard layouts and sizes with the most common for Latin based languages
being the QWERTY layout (named for the first 6 keys). The standard keyboard has 101 keys.
Notebooks have embedded keys accessible by special keys or by pressing key combinations (CTRL
or Command and P for example). Ergonomically designed keyboards are designed to make typing
easier. Hand held devices have various and different keyboard configurations and touch screens.
Some of the keys have a special use. They are referred to as command keys. The 3 most common are
the Control (CTRL), Alternate (Alt) and the Shift keys though there can be more (the Windows key
for example or the Command key). Each key on a standard keyboard has one or two characters.
Press the key to get the lower character and hold Shift to get the upper.
Removable Storage and/or Disk Drives: All disks need a drive to get information off-or read-and
put information on the disk-or write. Each drive is designed for a specific type of disk whether it is
a CD, DVD, hard disk or floppy. Often the term ‘disk’ and ‘drive’ are used to describe the same
thing but it helps to understand that the disk is the storage device which contains computer files-or
software-and the drive is the mechanism that runs the disk.

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