Computer Basics Hardware and Software

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

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

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

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

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

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

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…

Remember our diagram of the basic computer system?

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

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

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

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