1. Computer Basics
Hardware and Software

2. IPO IPO  Input-Processing-Outputting Input Unit Processing Unit
Output Unit

3. IPO - Continued Computers are tools that help us solve problems
Computers solve problems based on the information we give them; this information is called INPUT
The unit of the computer responsible for gathering the input is called the Input Unit

4. IPO - Continued
After the computer has the information, it has to do work to solve the problem; this stage is called PROCESSING
The unit of the computer responsible for processing is called the Central Processing Unit or the CPU
The computer needs to output the results of the work. This stage is called OUTPUT
The unit of the computer responsible for output is called the Output Unit

5. The Computer System Now we need another component CPU Input Unit
Output Unit
Memory (RAM)
Unit

6. (we will find out shortly)
WHY?
(we will find out shortly)

7. Hardware and Software
In a computer system, hardware consists of the physical components you can touch
Examples: keyboard, monitor, processor, hard disk, memory
Another important part of the computer that you can’t touch is called software
Software is the set of instructions that controls the hardware

8. Programs
Each complete set of instructions with a specific purpose is called a program
Examples of programs…
Microsoft Windows, MS Office, Video Games, MSN Messenger, viruses, hardware drivers
We’ll talk more about software and programs later…

9. Remember our diagram of the basic computer system?

10. The Computer System
CPU
Input Unit
Output Unit
Memory (RAM)
Unit

11. Memory Unit (RAM)
To run or execute a program means that the set of instructions that makes up the program have to be followed by the CPU
A program is like a recipe; when a computer runs a program, it is like a person following a recipe
While a computer is running a program, the instructions for that program have to be stored in memory which the processor can access

12. More RAM
RAM stands for Random Access Memory and is sometimes called primary memory or main memory
Because the CPU requires RAM to function in a meaningful way
RAM or main memory is essential to a computer, but tends to be expensive

13. Secondary Memory
Larger, cheaper secondary memory can be used to store large amounts of data that are accessed infrequently
Examples of secondary storage…
Hard disks, CD-ROMs, flash/USB drives, floppy disks