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| PC
Case |
Motherboard |
Central Processing Unit |
Random Access Memory |
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PC cases come in many different sizes
and designs. The options of desktop (flat) or tower (vertical)
cases are a matter of preference. The case pictured is a,
so called, Prescott compliant case (with CPU cooling duct
in the side) of Micro ATX format. PC cases are usually supplied
with a power supply |
The motherboard is the central component
of the PC.
Many modern motherboards come with integrated sound, video
and LAN connections. This reduces complexity and build costs
and increases reliability.
The motherboard shown is a MicroATX form factor |
The CPU (Central Processing Unit) is
the brain of the PC performing millions of calculations
per second.
Because it is essential that the CPU is kept cool, a large
fan is supplied. When building the PC leave plenty of room
around the fan to allow air to circulate |
RAM (Random Access Memory) only
holds data when the computer is running but works a lot
quicker than disk based storage helping the CPU to remember
work in hand.
The more memory you have - the quicker your computer. RAM
is measured in Mb (megabytes). 512 Mb is usually sufficient. |
| Memory
or Storage?
The concepts of
memory and storage are often confused especially since they
are both measured in the same units, for example megabytes
or gigabytes. Working memory (or RAM) helps the processor
by remembering data as the computer is working but data
is only stored so long as the computer is switched on. The
floppy, optical and hard drives illustrated on following
slides are all examples of storage and can hold data when
the computer is switched off. |
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| Hard disk drive |
Serial ATA cable |
Floppy disk drive |
Floppy drive
cable |
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A hard drive is essential to
the running of the PC and, because it has moving parts,
is the most likely point of failure within the PC. Although
computers on a network will not need a large capacity disk,
choosing a reliable brand is important.
Hard disk storage is measured in Gb (gigabytes). 80Gb is
usually sufficient |
These cables connect Serial
ATA devices (usually hard drives) and provide faster data
transfer than the IDE standard (see below) as well as being
more convenient to route in a small computer case. |
It is useful to include a floppy
drive in order to have the option to boot from a recovery
disk. Because of the small storage capacity and unreliability
of floppy disks, many users prefer to use a USB memory stick
to a floppy disk. Floppy disks can be a source of viruses |
The floppy cable is a ribbon
connector connecting the floppy drive to the motherboard.
Note the twist in the cable near one end. This is the end
that connects onto the drive.
Note the coloured edge (sometimes red). This goes nearest
to the power connector on the drive and towards the bottom
of the PC on the motherboard |
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| Optical drive |
IDE drive cable |
Motherboard Mask |
Screws |
| When
building network computers it isn’t strictly necessary to
include any optical drives such as CDRW or DVD as the users
will be mainly saving to network locations. Not having an
optical drive saves money and reduces the likelihood of users
installing pirated or unlicensed software |
These cables can connect up
to two IDE devices (hard drives or optical drives) to the
motherboard. The blue connector connects to the motherboard.
Note the coloured edge (sometimes red). This goes nearest
to the power connector on the drive and towards the bottom
of the PC on the motherboard |
The mask is the component inserted
into the back of the case that accommodates external connectors
on the motherboard. The mask supplied will be an exact match
for the motherboard and should be used to replace the one
supplied with the PC case |
The bag of screws supplied with
the case will be used to attach all of the components together
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