Introduction to Computers

Demonstrate an understanding of the information technology terms used in business.

1Define key information technology terms.

2Explain the concept of information technology.

3Use current information technology terminology appropriately.

WHAT IS A COMPUTER?A COMPUTER IS AN ELECTRONIC DEVICE THAT CAN:

1Do Arithmetic

2Follow Instructions

3Store and Retrieve Information

MANUFACTURERS OF COMPUTERS

▪APPLE

▪IBM

▪DELL

▪HEWLETT PACKARD

▪MDG

FOUR BASIC FEATURES OF A COMPUTER

REGARDLESS OF THEIR SIZE AND ORIGIN, ALL COMPUTERS HAVE 4 BASIC FEATURES.

1INPUT

2PROCESSING

3OUTPUT

4STORAGE

INPUT DEVICEA GENERAL NAME FOR ANY HARDWARE DEVICE THAT

CAN BE USED TO ENTER INFORMATION INTO A COMPUTER SYSTEM.

▪EXAMPLE:▸Keyboard

▸POINTING DEVICES: ALSO USED AS INPUT DEVICES FOR COMMUNICATING WITH COMPUTERS ARE:▸Mouse▸Joystick

SCANNER

▪IS AN INPUT DEVICE USED TO COPY A PRINTED PAGE INTO THE COMPUTER'S MEMORY AND TRANSFORM THE IMAGE INTO DIGITAL DATA. VARIOUS SCANNERS CAN READ TEXT, IMAGES, OR BAR CODE.

INPUT MEDIUM

THE MATERIAL ON WHICH INFORMATION IS STORED BEFORE IT IS ENTERED INTO A COMPUTER SYSTEM.

▪Floppy Disk

▪Hard Disk

▪CD ROM (Compact Disc-Read-Only-Memory disc)

▪DVD (Digital Versatile/Video Disk)

▪Blue Ray

▪USB drives / Flash Memory sticks etc.

OUTPUT DEVICEA GENERAL NAME TO DESCRIBE ANY HARDWARE

DEVICE, WHICH CAN BE USED TO DISPLAY ANSWERS OR INFORMATION GENERATED BY A COMPUTER.

▪EXAMPLES:▸Printer▸Monitor

RESOLUTION:THE CLARITY AND AMOUNT OF DETAIL THAT A MONITOR CAN PROJECT.

PRINTOUT OR HARD COPY:WHEN THE INFORMATION APPEARS ON A PIECE OF PAPER.

Laser Printer

•MOST EXPENSIVE PRINTER CAPABLE OF REPRODUCING FINE QUALITY GRAPHICS, SCANNED PHOTOGRAPHS, AND TEXTUAL MATERIAL. IT WORKS WITH A COMBINATION OF LASER LIGHT AND A PHOTOCOPYING PROCESS, AND IS WELL SUITED FOR PRINTING PROFESSIONAL- LOOKING FLYERS, NEWSLETTERS, NEWSPAPERS AND MAGAZINES. (SOME CAN PRINT OVER 200 PAGES PER MINUTE)

Ink Jet Printer

▪A PRINT HEAD MOVES ACROSS THE PAGE SPRAYING FINE JETS OF INK TO FORM THE IMAGE. (Inexpensive, colour, excellent for home use, ink cartridges can be expensive)

▪SLOWER THAN LASER PRINTERS

▪LESS EXPENSIVE THAN LASER PRINTERS

STORAGEMICROCOMPUTER SYSTEMS HAVE TWO STORAGE

AREAS:

▪INTERNAL MEMORY - IS FOUND INSIDE THE PROCESSOR UNIT AND IS CALLED MAIN MEMORY.

RANDOM ACCESS MEMORY

▪(RAM)-IT IS AN ERASABLE MEMORY CHIP WHICH IS USED TO TEMPORARILY STORE COMPUTER PROGRAMS. NICKNAMED USER MEMORY. WHEN THE POWER IS SHUT OFF, ALL INFORMATION CONTAINED IN RAM VANISHES. (Like erasing the blackboad in a classroom)

INTERNAL MEMORY

READ ONLY MEMORY(ROM)

▪ROM - IS USED FOR THE PERMANENT STORAGE OF SYSTEM SOFTWARE PROVIDED BY THE MANUFACTURER LIKE THE LANGUAGE PROCESSOR AND THE BIOS (Basic Input/Ouput System). THIS MEMORY CANNOT BE MODIFIED OR ERASED BY THE USER. IT REMAINS INTACT EVEN WHEN THE POWER IS SHUT OFF. (NICKNAMED FIRMWARE)

THESE DEVICES CAN STORE INFORMATION ON REUSABLE, LONG-LASTING MEDIA SUCH AS:

▪FLOPPY DISK

▪HARD DISK

▪CD ROM

▪DVD

▪USB DRIVES / FLASH MEMORY

▪EXTERNAL HARD DRIVES

EXTERNAL MEMORY▪EXTERNAL MEMORY - IS FOUND OUTSIDE THE

PROCESSOR UNIT AND IS CALLED AUXILIARY STORAGE.

FLOPPY DISK

▪ARE INEXPENSIVE, LOW-VOLUME STORAGE MEDIA FOR MICROCOMPUTERS. (3.5",2") USED TO LOAD NEW PROGRAMS OR DATA ONTO THE HARD DISK, TRADE DATA, MAKE BACKUP COPIES, SAVE FILES AND PROGRAMS FOR MOVING FROM ONE COMPUTER TO ANOTHER.

▪NOW BECOMING OBSOLETE

HARD DISK

▪ARE HIGH-VOLUME STORAGE MEDIA FOR MICROCOMPUTERS, AND MAINFRAMES. THE DRIVES SPIN AT 150 KM./HR., PROVIDING FAST RESPONSE. THE STORAGE CAPACITY RANGES FROM 1 TO 500 GIGABYTES (Gb) AND NOW OVER 1000 GIGABYTES = 1 TERABYTE (Tb). THE COMPUTER’S PRIMARY FILING CABINET.

CD-ROM - (for reading CDs only)CD - Writer RW - (for reading and saving onto CDs)

▪CD-ROM - "COMPACT DISK-READ ONLY MEMORY" ARE HIGH-VOLUME STORAGE MEDIA THAT CAN STORE "STILL" PHOTOGRAPHS OR MOTION PICTURES AND SOUND TRACKS AS WELL AS NORMAL COMPUTER OUTPUT. THE UNIT CAN RANDOMLY LOCATE ANY FRAME IN FIVE SECONDS OR LESS. THE NAME IMPLIES THAT YOU CANNOT CHANGE THE INFORMATION ON THE DISK, JUST AS YOU CANNOT RECORD OVER AN AUDIO CD. CAN STORE ABOUT 700 MB, OR ABOUT 500 TIMES AS MUCH INFORMATION AS A DISKETTE.

DVD / BLURAY

▪DVD (DIGITAL VERSATILE DISK or DIGITAL VIDEO DISK) HAS REVOLUTIONIZED HOME ENTERTAINMENT. USING NEW COMPRESSION TECHNOLOGIES, A SINGLE DVD (WHICH IS THE SAME SIZE AS A STANDARD COMPACT DISK) CAN STORE AN ENTIRE FULL-LENGTH MOVIE (ABOUT 4.7 GIGABYTES)

▪HIGH DEFINITION MOVIES ARE NOW STORED ON BLURAY DISKS WHICH CAN STORE ABOUT 25 TO 50 GB DEPENDING ON THE TYPE OF DISK

USB Drive

•USB or Flash Memory drives are RAM memory devices integrated with a USB (universal serial bus) connector. They are typically small, lightweight, removable and rewritable.

•They are becoming very inexpensive and can store between 256 kilobytes and 16 Giga bytes or more

HOW THE COMPUTER STORES INFORMATION

BIT

▪A BINARY DIGIT. ONE STORAGE POSITION IN A COMPUTER CIRCUIT THAT CAN BE EITHER ELECTRICALLY "ON" OR "OFF".

BYTE

▪THE NUMBER OF BITS WHICH ARE NEEDED TO CODE ONE CHARACTER (A LETTER, NUMBER, OR SYMBOL) IN A PARTICULAR COMPUTER. USUALLY EIGHT BITS = BYTE

BINARY1000001 = A1000010 = B1000011 = C

ASCII = American Standard Code for Information Interchange

▪ K = GREEK LETTER FOR 1 000

▪ KILOBYTE = 1000 BYTES

▪ MEGABYTE - A MILLION CHARACTERS OR 1024 X 1024 BYTES OR 1024 K BYTES. REFERS TO MAIN MEMORY OR DISK STORAGE CAPACITY. IS EQUIVALENT TO STORING 125 ONE-PAGE BUSINESS LETTERS.

ONE SCREENFUL OF INFORMATION REQUIRES 4 K OF STORAGE, SO A COMPUTER WITH 16 MEGABYTES OF MAIN MEMORY COULD HOLD 4000 SCREENFULS OF

INFORMATION.

▪GIGABYTE - A BILLION BYTES. USUALLY REFERS TO THE MEMORY CAPACITY OF SOME AUXILIARY STORAGE MEDIA.

▪TERABYTE - A TRILLION BYTES.

▪EXABYTE - ONE MILLION TERABYTES.

▪BYTE = 1 ALPHABETIC CHARACTER OR NUMERIC DIGIT

▪1024 BYTES = 1 KILOBYTE OR 1000 BYTES

▪1024 KILOBYTES = 1 MEGABYTE OR A MILLION BYTES

▪1024 MEGABYTES = 1 GIGABYTE OR A BILLION BYTES▪1024 GIGABYTES= 1 TERABYTE OR A TRILLION BYTES▪1 MILLION TERABYTES = 1 EXABYTE

SUMMARY (THE TRUTH AND NOTHING BUT THE TRUTH)

AN AVERAGE PAGE OF TEXT HOLDS ABOUT 300 WORDS. ONE PAGE OF TEXT WILL AVERAGE OUT TO ABOUT 2000 CHARACTERS. THEREFORE 1 MEGABYTE WILL HOLD ABOUT 500 PAGES OF TEXT. 1,000,000 / 2000

CENTRAL PROCESSING UNIT(CPU)

THE BRAIN OF THE COMPUTER. IT IS THE MAIN COMPONENT OF THE COMPUTER. IT IS THE COMPUTER. IT CONTROLS THE OPERATION OF ALL COMPUTER EQUIPMENT. IT MAKES IT POSSIBLE FOR THE COMPUTER TO DO ARITHMETIC, MAKE DECISIONS, AND STORE AND MANIPULATE INFORMATION. THE CPU IS ALL CONTAINED WITHIN A TINY ELECTRONIC CIRCUIT CALLED A CHIP. THE CPU OF A MODERN COMPUTER IS A TINY DEVICE, NOT MUCH LARGER THAN A THUMBNAIL. MANUFACTURERS INCLUDE INTEL AND MOTOROLA.EXAMPLES OF WHERE WE FIND CHIPS TODAY (MICROPROCESSORS)- CARS -TELEPHONES - VIDEOGAMES - TOYS - MICROWAVES- CALCULATORS- APPLIANCES

ARITHMETIC LOGIC UNIT -"ALU" A SECTION ON THE MICROPROCESSOR CHIP. THE LOGIC CIRCUITRY DESIGNED TO PERFORM OPERATIONS SUCH AS +,-,X, AND ÷. ALSO, IT CAN PERFORM LOGICAL COMPARISONS. SUCH AS "IS A > B?".

OPERATING SYSTEM - THE COMPUTER MANUFACTURER MUST INCLUDE A PROGRAM WITH THE MACHINE TO MAKE THE COMPUTER FUNCTION. MUST BE PRESENT BEFORE ANY OTHER SOFTWARE CAN BE RUN. EXAMPLES: DOS, WINDOWS, LINUX, UNIX.PROVIDES THE INTELLIGENCE THAT ALLOWS THE MICROPROCESSOR TO ACT AS THE "TRAFFIC COP" CONTROLLING THE PERIPHERALS AND THE FLOW OF INFORMATION.

LANGUAGE PROCESSOR - (COMPUTER LANGUAGE) MANUFACTURERS’ SOFTWARE USED TO TRANSLATE INSTRUCTIONS THE PROGRAMMER PROVIDES INTO ELECTRICAL IMPULSES THAT THE COMPUTER CAN UNDERSTAND. EXAMPLES: BASIC, FORTRAN, COBOL, AND C. HIGH LEVEL LANGUAGE - COMPUTER LANGUAGE THAT IS LIKE ENGLISH EXAMPLES: VISUAL BASIC, JAVALOW LEVEL LANGUAGE - COMPUTER LANGUAGE CLOSE TO WHAT THE COMPUTER UNDERSTANDS EXAMPLE: MACHINE LANGUAGE 10111101 “BINARY”APPLICATION SOFTWARE - REFERS TO PROGRAMS OTHER THAN “SYSTEM SOFTWARE”, THAT ARE WRITTEN TO ASSIST PEOPLE IN HANDLING CERTAIN TASKS.

SPEED

HOW FAST IS THAT COMPUTERNEVER FAST ENOUGH

▪MEGAHERTZ - (MHZ.) IS 1 MILLION CYCLES, OR PULSES, PER SECOND. FOR EXAMPLE, A PARTICULAR PROCESSOR RUNNING AT A CLOCK SPEED OF 600 MHZ. CAN PERFORM UP TO 600 MILLION INSTRUCTIONS IN 1 SECOND.

▪GIGAHERTZ - (GHz.) IS 1 BILLION CYCLES, OR PULSES, PER SECOND. TODAY'S PERSONAL COMPUTERS RUN AT A CLOCK SPEED OF 2.4 GHz. WHICH MEANS THEY CAN PERFORM UP TO 2400 MILLION INSTRUCTIONS IN 1 SECOND OR WE COULD SAY 2.4 BILLION INSTRUCTIONS IN 1 SECOND.

TYPES OF COMPUTERS

▪SUPERCOMPUTERS - THE MOST POWERFUL COMPUTERS AVAILABLE TODAY. THEY ARE USED BY LARGE ORGANIZATIONS (SUCH AS BANKS, INSURANCE COMPANIES RESEARCH LABS, NASA) TO SOLVE COMPLEX MATHEMATICAL PROBLEMS AT RATES EXCEEDING 3 TRILLION OPERATIONS PER SECOND. THEY COST BETWEEN $3 MILLION AND $30 MILLION, AND CAN BE AS LARGE AS AN ENTIRE ROOM. WE COULD NOT SEND THE SPACE SHUTTLE INTO SPACE OR PROBES TO MARS WITHOUT THE SUPERCOMPUTER.

▪MAINFRAME COMPUTER - SECOND MOST POWERFUL COMPUTER, A LARGE, MULTIUSER COMPUTER SYSTEM DESIGNED TO HANDLE MASSIVE AMOUNTS OF INPUT, OUTPUT, AND STORAGE. USUALLY COMPOSED OF ONE OR MORE POWERFUL CPUs CONNECTED TO MANY TERMINALS. USED BY LARGE ORGANIZATIONS. EXAMPLES: SCHOOL BOARDS, INSURANCE CO., UNIVERSITIES, AND COLLEGES. THEY COST BETWEEN $100,000 AND SEVERAL $MILLION. OPERATE AT SPEEDS EXCEEDING 125 MILLION INSTRUCTIONS PER SECOND.

In the early days of computing, mainframes were huge computers that could fill an entire room or even a whole floor! As the size of computers has diminished while the power has increased, the term mainframe has fallen

out of use in favor of enterprise server. You'll still hear the term used, particularly in large companies to describe the huge machines processing millions of transactions every day.

▪PERSONAL COMPUTER (PC) - THE MOST COMMON TYPE OF COMPUTER FOUND IN AN OFFICE, CLASSROOM, OR HOME. THE PC IS DESIGNED TO FIT ON A DESK AND BE USED BY ONE PERSON AT A TIME; ALSO CALLED A MICROCOMPUTER. THEY COST BETWEEN $ 300 AND $15,000.

▪LAPTOP - ARE PORTABLE COMPUTERS THAT WEIGH LESS THAN 5 KG. THEY POSSESS ALL THE KEY COMPONENTS THAT PCs HAVE, AND PERFORM MOST OF THE SAME FUNCTIONS. THEY COST BETWEEN $600 AND $ 3500.

▪PERSONAL DIGITAL ASSISTANT - (PDA) ARE TINY COMPUTERS THAT FIT INTO THE PALM OF THE USER'S HAND. THEY ARE LIGHTWEIGHT AND PORTABLE, BUT HAVE LIMITED STORAGE SPACE. HANDHELD RELY ON A SMALL KEYBOARD FOR INPUT, PALM SIZE USERS USE A PEN-LIKE STYLUS TO WRITE OR DRAW ON THE SCREEN.

A personal digital assistant, or PDA, a remarkable, tiny, fully functional computer that you can hold in one hand. And unlike that paper organizer, a PDA can hold your downloaded e-mail and play music.

▪WEARABLE - The latest trend in computing is wearable computers. Essentially, common computer applications (e-mail, database, multimedia, calendar/scheduler) are integrated into watches, cell phones, visors and even clothing!

These days, cell phones provide an incredible array of functions, and new ones are being added at a breakneck pace. These are called smartphones.

Depending on the cell-phone model, you can:

Store contact information Make task or to-do lists Keep track of appointments and set reminders Use the built-in calculator for simple math Send or receive e-mail Get information (news, entertainment, stock quotes) from the Internet Play simple games Integrate other devices such as PDAs, MP3 players and GPS receivers

NETWORKS

MODEM - an input/output device that allows computers to communicate through telephone lines or cable.

NETWORK - a system of interconnected computers that communicate with one another and share applications, data, and hardware components.

SERVER – a more powerful computer containing programs and information that can be shared by multiple users and computers on a network.

LAN - Local Area Network - consists of a group of networked computers that are all located in one building, such as a school or classroom.

WAN - Wide Area Network - a group of networked computers located in a variety of locations in a large geographic area. i.e. world wide web (www)