Lecture 5:Using Computers:

Important Ideas

Tonga Institute of Higher EducationIT 141: Information Systems

Topics

What is a computer Relationship between hardware and

software Parts of a typical computer Peripheral Devices User interfaces Artificial Intelligence

What is a computer?

Before the 1940s, a computer was a person who did math problems all day.

For example, in a war the army needed to know where bombs would land and how to aim the guns.

To do this people needed to do math equations Typically the “computers” were all women and it was

considered an easy, but repetitive job In 1945, during World War II, scientists started

working on an electronic computer called EDVAC The computer was based on ideas by John von

Neumann

John Von Neumann

What a computer does

Input A computer accepts input from a

variety of devices: mouse, keyboard, scanner…

It will then process this input in some manner based on what it has been programmed to do

What a computer does

Process data Data comes in many forms for a computer,

images, movies, text files, keyboard input. A computer must be programmed to decide

what to do with the data The part that decides is the central processing

unit (CPU), usually called the processor Based on what program is running, the data

will be changed or used in different ways

What a computer does

Storing data If a computer couldn’t save data, it would not

be very useful. Each time it started you would need to put back all your data, even the operating system (like Windows XP)

The memory of the computer is located in a few places.

On the Hard Disk, a magnetic disc that saves data for about 10 years before dying

In RAM, which is memory inside the computer that the processor uses to remember things while it is running

What a computer does

Output data If a computer couldn’t output data, you

wouldn’t know what it was doing. A monitor is an output device, just like

a printer, a fax machine, even a modem.

Output is the result of data being processed

Computer Systems

Hardware The hardware of the computer is responsible

for making things happen Examples:

executing instructions, storing data, sending data over a network Reading input from a mouse

But the hardware would not perform any of these actions without something telling it what to do

Hardware needs software to tell it what it should do, just like a car needs a person to drive it

Computer Systems

Software Software is a set of instructions that when

performed in order produces a "program" Without software, a computer would do

nothing. The hardware needs instructions (that come

from software) to tell it what actions to perform If you tried to use a CD player without a CD,

nothing would happen Software can instruct the hardware to print a

document, read a CD or display graphics on a monitor

Types of computers

Personal Computers (PCs) Used in home and office. Typically cost

about $500 US and can either stand alone or be networked together

Types of Computers

Laptops Personal computers that have

been made smaller so they may be transported easily

All the pieces inside a laptop are custom-made to fit and work within a small space

Laptops are usually more expensive because the parts have to be specially made.

Types of Computers Supercomputers

Fastest and most expensive. They can cost upwards of 35 million dollars.

Used for “computer-intensive” tasks like weather prediction, molecular computing, breaking codes

Problems that requires many calculations with math formulas can be used on a supercomputer

A team of Japanese scientists used the world’s fastest computer to predict weather for the next 100 years for the entire world.

The fastest supercomputers can do 1 trillion calculations per second

System Components

Computer Networks A network connects multiple computers together so

that they communicate in some way. For example, sharing data and files, playing games or using videoconferencing.

Networks, if made correctly, should be secure. To gain access to the network you must supply a user name and password, just like our network.

The username and password are then sent over the network, through the wires, to the server. The server will then check to see if the right password was entered for that user.

If it was the right password, the user will gain access. This is called “authentication”

The User Interface

The user interface is the way that the user works with the computer.

Usually, this involves using the mouse and keyboard while viewing the actions on a monitor.

The importance of a good user interface cannot be underestimated.

If people are not able to use programs because they are too difficult or complicated, the program is not useful

Good user interfaces are very important to successful software.

User Interfaces: The Command Line A prompt is a message that asks the user to

type some information. This kind of interface is usually called the

command line interface Prompts are used with “text-based” programs. This means programs that do not have

graphics. On Windows XP, you can access a prompt by

going to Start Run and typing “cmd.”

A command prompt

Using Commands

Commands are words that you can enter on a prompt that will perform some action.

Some like print, save, begin are self-explanatory Some commands are harder to understand and

take a long time to learn them all When you use a prompt and commands, this is

called a command-prompt user interface. The opposite is to use graphics, like Windows. This is a graphical user interface (GUI)

The GUI: Menus and Dialogs

Menus display a list of commands in a graphical display. They simplify the use of a program

Dialog boxes are windows that pop-up and ask for the user to enter some sort of data in order for the program to continue running

Graphical Objects

Window – a box that opens on the screen that allows the user to do something

Button - a box, that if pressed, will execute a command and do something in the program

Icon – a small picture that represents the program.

Pointing Devices

A pointing device is known as a mouse. Some have two buttons, some three

By moving the device and clicking once or twice, different commands can be executed on a GUI (graphical user interface)

Artificial Intelligence

How much “intelligence” can a computer have? And what is intelligence?

Alan Turing, in the 30s, created the Turing Test, to determine artificial intelligence.

In his test, he first put a person in front of a computer and let him type whatever he wanted.

If the computer responded and the person could not determine if it was a person or a computer at the other end, then the other side was "intelligent"

If the other side was a computer, then it was "artificially intelligent"

Artificial Intelligence Today, many researchers use the idea of artificial

intelligence to solve problems for: Speech Recognition Financial Predictions Weather forecasting Network traffic routing

This means that they try to make computers “think” for themselves, instead of doing only what they are “programmed” to do

Whether we will ever be able to make a computer that can really think on its own is a great matter of debate amongst computer scientists.

Summary

What is a computer What does a computer do Computer Systems Types of computers Networks The user interface AI