2 What is a Computer? A COMPUTER is an electronic device that can: Receive informationPerform processesProduce outputStore info for future use.
3 Information Processing Cycle InputProcessOutputStorage
4 Hardware vs. SoftwareHardware - the physical parts that make up the computere.g. CPU, memory, disks, CD-ROM drives, printer.Software - computer programs and applications.Operating system, word processor, games, etc.
5 Hardware: physical devices that comprise a computer system Monitor (output)Speaker (output)System unit(processor, memory…)Printer (output)Storage devices(CD-RW, Floppy, Hard disk, zip,…)Mouse (input)Scanner (input)Keyboard (input)
6 What Are The Primary Components Of A Computer ? Input devices.Central Processing Unit (control unit and arithmetic/logic unit).Memory.Output devices.Storage devices.
8 Central Processing Unit The central processing unit (CPU) is the “brain” of the computer. It:Interprets instructions to the computer (control unit),Performs the arithmetic and logical processing (ALU)
9 Memory Memory, also called Random Access Memory or RAM stores: instructions waiting to be executeddata needed by those instructionsresults of processed dataAny information stored in RAM is lost when the computer is turned off.
10 MemoryData in memory is stored as binary digits (BITS) e.g1 BYTE = 8 bits1 byte usually stores 1 text character.
11 Amount Of RAM In Computers We measure the size of memory by telling how many bytes it can hold.1 kilobyte = 210 bytes = 1024 bits1 megabyte = 220 bytes = ~1 million bytes1 gigabyte = 230 bytes = ~1 billion bytes1 terabyte = 240 bytes = ~1 trillion bytesOne megabyte can hold approximately 500 pages of text information.
12 Output DevicesOutput devices make the information resulting from the processing available for use.printer - produces a hard copy of your outputscreen - produces a soft copy of your outputspeakers, etc.
13 Storage DevicesAuxiliary storage devices are used for permanent storage of data.hard disksfloppy diskscompact discs – CD and DVD drivesflash cards
14 Hard DisksPermanent storage that is inside of the computer, and NOT portable.Consists of several platters which spin very fastTypical hard disks range from 40 GB to 200 GB
15 Floppy Disks – 1.44 MBA floppy disk is a portable, inexpensive storage medium that consists of a thin, circular, flexible plastic disk with a magnetic coating enclosed in a square-shaped plastic shell.
16 Compact Discs CD-ROM (read only memory), CD-RW – (rewritable) DVD-ROM DVD+RWTypical CD’s can store about 700 MBTypical DVD’s can store up to 17 GB
17 Flash Cards Advantages: Small, easy to carry around High memory capacity – up to 8 GBNote:There are several different form factors of flash cards, including Compact Flash, SmartMedia, PCMCIA, and Small Form Factor Flash Card.
18 Software A computer program or software tells it exactly what to do. A computer program is a set of instructions to the computer.The computer does one instruction at a time.
19 SoftwareComputer software is the key to productive use of computers. Software can be categorized into two types:System softwareApplication software.
20 System SoftwareThe most important system software is the operating system.Examples of operating systems:Windows, DOS, Apple, UNIX
21 Application SoftwareApplication Software consists of programs that tell a computer how to produce information. Some of the more commonly used packages are:Word processingElectronic spreadsheetDatabasePresentation graphics