Computer Basics Which computer should I buy? What do I get for an extra $775 and do I even need it ? Desktop We need to understand several things before going out and buying a computer . What are the different components of a computer system and how do they work?
What do I get for an extra $775 and do I even need it?
Tower Box: Central Processing Unit - CPU (motherboard), power supply, Main Memory (RAM), Auxiliary Memory devices: Hard drive, CD, DVD, etc.
A Laptop – with CPU, monitor, keyboard, touch pad & speakers
Output devices buying a computerHow these Components Work Together
Main/Primary Memory (RAM)
Hard drive CD R/W, DVD, floppy drive, ZIP drive, Flash memory
Hard Drive Bus
User hits buying a computer
the ‘2’ key then
2 + The
Y = X+2
Y = 4
Output 4 on
the screenCPU – Central Processing Unit works with memory to execute the arithmetic and logical processes
The performance of the CPU is dependent on both its speed and memory
Different Processors have different “clock” speeds and different memory “bus”speeds – A faster clock speed won’t necessarily speed up your processing if the bus speed is too slow!
GHz - a unit of frequency equal to one billion cycles per second
What is RAM memory? buying a computer
How does Memory Work? buying a computer
How is Information Stored in Memory? buying a computer
All data is represented by a string of 0’s and 1’s.
All information is translated by a set of instructions into this format and then processed
Static Random Access Memory
doesn’t need to be “refreshed” - but like all RAM, is erased when the power is OFF
10 ns speed
DRAM (Dynamic RAM) is a type of memory that is constantly refreshed or will loose its contents.
SDRAM (Synchronous Dynamic RAM) – designed to work with the CPU clock to work faster than DRAM
DDR SDRAM (Double Data Rate SDRAM) – works twice as fast as SDRAM
So how much and what type of memory should you get? buying a computer
To save data for later use we can store data on Secondary (Auxiliary) Memory devices
Auxiliary Memory is cheaper/slower than Primary memory but is not erased when the Power Supply is OFF.
Programs to control computer operations are called Operating Systems (OS)
..and promised soon…. VISTA
Computer programs written to perform specified tasks. They work in tandem with specific Operating Systems
What software you need will affect you decision of what hardware to buy…For example how much hard drive space will you need with the following requirements?
In GB: 1.5+.45+.8+.28+150*.005=3.78
PS2 Connection Newer Technology – faster than a Serial
Serial Connection Oldest Technology - slow
USB Connection Newest Technology - fastest
$200 - $2000+
Most systems do not come standard with a monitor unless buying a “complete package”. Consider the following when selecting a computer:
To go with your fancy new monitor you’ll need a video card that is compatible
$20 - $200+
Your new computer system may or may not come with other peripheral devices including
Speakers and sound cards
Black & connections available on your system.. And the price!
$50 - $10,000+
Unless your purchasing a “complete package” your system will probably not come with a printer. The two most common printer types are:
Its not always with printer that gets you.. It’s the price of the ink supplies!
Desktop connections available on your system.. And the price!
Easy to use at a desk – larger keyboard
Least expensive and available with greatest speeds & memory
More expensive than a desktop
Keyboard, mouse -not quite as easy to useA desktop, a laptop, a tablet PC?
$300+ incl. monitor
The simplest communication is transmission of data over a communication channel between two computers
Computer <--> Modem
<--> Modem <--> Computer
Networking - connecting a group of computers together communication channel between two computers
Virus Protection – get Anti-virus software and keep it up to date
Firewall – Software/Hardware that denies entry to all incoming traffic except those specifically requested or allowed
Spam Filters –
Available on most email packages or by providers and can be “customized”