• To know what technical specifications
• To understand the considerations of
choosing computer components for a
• Do- create a technical user guide for Sally.
The technical specification
of a device in a computer
system is a list of its
properties. It usually
refers to the capacity and
/or performance of the
What should be considered when
choosing a processor?
• Processors fall into 3 groups:
1. Intel Pentium Series
2. AMD Athlon and Duron series
3. Apple G series.
• If you buy an Apple system it will have a Apple Processor. This is not
interchangeable with other processing systems.
• The other series of processors are interchangeable and are used by many
different computer manufacturers
• The speed of the processor is measured in HERTZ. This is the rate at which
the Control Unit in the CPU works.
• Faster processors are not necessarily the most efficient. Processors can also
be measured by performance and the better the performance the faster they
What should I consider when
choosing a Main Memory?
• The main memory or RAM is made up of semiconductor chips.
• The main property of RAM is its CAPACITY. This is measured in
megabytes or gigabytes. Which is the number of bytes which can be
stored when the computer is switched on.
• Obviously the more capacity that RAM has the more data it can store
whilst tasks on the computer are carried out.
What should I consider when
choosing a screen?
• Screens are measured in two ways:
1. Size- the length along the diagonal of the display area.
2. Resolution- the number of pixels( colour dots) that it can
There are two types of screen
• CRT monitor- a Cathode Ray Tube which is the type we are
• LCD- a Liquid Crystal Display which gives a completely
What to choose when choosing a
• These are common types of printer
• Inkjet- these squeeze bubbles of ink onto paper to form characters and
images. The quality of output is measured in dots per inch- more dots
per inch give a higher quality, but take longer to print. They can print
onto variety of types of paper. The ink is stored in ink cartridges.
• Laser printers- these use the same technology as photocopiers. The
laser places an electrostatic charge on a drum to match the image.
Toner dust is attracted to the drum and when the paper presses on the
drum it is heated and the image forms. Laser printers produce high
quality printouts but are expensive. They are faster in printing than an
What to consider when choosing
• Storage media may be
• Read Only memory (CD-ROM) the data is stored permanently
cannot be erased. They can hold 650 Mb of data
• CD-R- record able data is stored permanently and cannot be
erased but more data can be added. They can hold 700 Mb of data.
• CD RW- Read and write data can be erased and added.
There are two technologies for storing data:
Magnetic and Optical.
Hard Disks – are magnetic storage devices and read and write media.
They have a high capacity and are used as the main backing store
for almost all computers.
Floppy Disks- are small and magnetic, read and write
media. They can only hold 1.44 megabytes of data.
You have to create a simple user guide for Sally to
consider Technical specifications of a computer system
that would suit her needs.
You will need to create a leaflet that investigates the
specifications and costs of two computer systems. Then
to achieve higher grades you will need to explain to
Sally which computer would suit her business best and
justify these choices.
Here we have considered hardware but you will also
need to consider the software Sally will need to
complete her tasks.