1 introdcution tocomputernursing [compatibility mode]

Introduction to Computers

by

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What Is A Computer?A computer is an electronic device,operating under the control of instructions(software) stored in its own memory unit,that can accept data (input), manipulatedata (process), and produce information

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data (process), and produce information(output) from the processing.Computer comes form the word computeCommonly Operated Machine ParticularlyUsed for Training Education and Research

Flow Diagram

Input Device

OutputDeviceControl

Unit

Central Processing Unit

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Device

MemoryUnit ALU

CharacteristicsVersatilityAccuracy

DiligenceNo Feelings

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AccuracyPower of rememberingSpeedNo IQCommon data usedStorage

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Evolution of Computers

History of Computers - Long, Long Ago

� beads on rods to count and calculate� still widely used in Asia!

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� still widely used in Asia!

History of Computers - Way Back When

� Slide Rule 1630

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� Slide Rule 1630� based on Napier’s rules for logarithms

� used until 1970s

History of Computers - 19th Century

� first stored program -

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� first stored program -metal cards

� first computer manufacturing

� still in use today!

Charles Babbage - 1792-1871

� Difference Engine c.1822 � huge calculator, never

finished

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finished� Analytical Engine 1833� could store numbers� calculating “mill” used

punched metal cards for instructions

� powered by steam!� accurate to six decimal places

� In the mid-1940s, John Von Neumann invented a machine in storing programs and calculations.

Evolution of Microprocessor

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and calculations.� The last 20 years has seen a rapid development of the smallest computers,which is so called – Microcomputers.

� This IC computer was designed by Hoff and Stanley Mazor.

� The MOS design of a 4004 4-bit chip called- Microprocessor in 1971.� This chip is the heart of the computer

Evolution of Microprocessor

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� This chip is the heart of the computer system, commonly referred as CPU (Central processing unit).� The latest generation Intel pentium processor have a speed up to 200 MHz.

The First Microprocessor – 1971

� The 4004 had 2,250 transistors

� four-bit chunks (four

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� four-bit chunks (four 1’s or 0’s)

� 108Khz� Called “Microchip”

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Computer Generations

First Generations1. VACUUM TUBES: 1942-1955

ENIAC Electronic Numerical Integrator And Calculator

EDVAC Electronic Discrete Variable Automatic Computer1946, JP Eckert and JW Mauchly

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EDVAC Electronic Discrete Variable Automatic ComputerDr.John Von NeumannEDSAC Electronic Delay Storage Automatic Calculator1949, Professor Maurica Wilkes

VACUUM TUBES: 1942-1955

Vacuum Tubes - 1942 - 1955

� First Generation Electronic Computers used Vacuum TubesVacuum tubes are glass tubes

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� Vacuum tubes are glass tubes with circuits inside.

� Vacuum tubes have no air inside of them, which protects the circuitry.

First Generations1. VACUUM TUBES: 1942-1955

Manchester Mark I

UNIVAC Universal Automatic ComputerProfessor MHA Newmann

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UNIVAC Universal Automatic Computer1951 . UNIVAC I in 1952 by IBM. UNIVAC II in 1954 by GEC


UNIVAC - 1951 � first fully electronic digital computer built in the U.S.

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the U.S. � Created at the University of Pennsylvania

� ENIAC weighed 30 tons � contained 18,000 vacuum tubes

� Cost a paltry $487,000

Grace Hopper� Programmed UNIVAC� Recipient of Computer Science’s first “Man of the Year Award

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the Year Award”

First Computer Bug - 1945� Relay switches part of computers

� Grace Hopper found a moth

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found a moth stuck in a relay responsible for a malfunction

� Called it “debugging” a computer

Second Generations2. TRANSISTORS: 1955-1964

First Transistor� Uses Silicon� developed in 1948� won a Nobel prize

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TRANSISTORS: 1955-1964

� won a Nobel prize� on-off switch� Second Generation

Computers used Transistors, starting in 1956

Third Generations3. INTEGRATED CIRCUITS: 1964-1975

� IBM 360 1964� ALO

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IC1964-1975

� Mini computers� ECIL- TDC 316 , 332

Third Generation – 1964-1971� 1964-1971� Integrated Circuit� Operating System

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� Operating System� Getting smaller, cheaper

What is a Microchip?� Very Large Scale Integrated Circuit (VLSIC)� Transistors, resistors, and capacitors

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� Transistors, resistors, and capacitors� 4004 had 2,250 transistors� Pentium IV has 42 MILLION transistors� Each transistor 0.13 microns (10-6 meters)

Fourth Generations 4. VERY LARGE-SCALE INTEGRATED (VLSI) CIRCUITS:

1975 onwards

� Large Integration� Portable� Minimum maintenance on Hardware

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� Minimum maintenance on Hardware� Heat generated is negligible� No AC is required� Much faster



IC1964-1975

VLSI1975

Birth of Personal Computers - 1975

� 256 byte memory (not Kilobytes or Megabytes)

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Megabytes)� 2 MHz Intel 8080 chips

� Just a box with flashing lights

� cost $395 kit, $495 assembled.

IBM PC - 1981� IBM-Intel-Microsoft joint venture� First wide-selling personal computer used in business

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� 8088 Microchip - 29,000 transistors� 4.77 Mhz processing speed

� 256 K RAM (Random Access Memory) standard

� One or two floppy disk drives

Apple Computers� Founded 1977� Apple II released 1977� widely used in schools

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� Macintosh (left)� released in 1984, Motorola

68000 Microchip processor� first commercial computer with

graphical user interface (GUI) and pointing device (mouse)

Computers Progress UNIVAC

(1951-1970) (1968 vers.)

Mits Altair (1975)

IBM PC (1981)

Macintosh (1984)

Pentium IV

Circuits

Integrated Circuits

2 Intel 8080 Microchip

Intel 8088 Microchip - 29,000 Transistors

Motorola 68000

Intel P-IV Microchip - 7.5 million transistors

RAM 512 K 265 Bytes 256 KB 256 MB

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RAM Memory

512 K 265 Bytes 256 KB 256 MB

Speed 1.3 MHz 2 KHz 4.77 MHz 3200 MHz = 3.2 GHz

Storage 100 MB Hard Drive

8” Floppy Drive

Floppy Drive

Floppy Drives

Hard Drive, Floppy, CD-Rom

Size Whole Room

Briefcase (no monitor)

Briefcase + Monitor

Two shoeboxes (integrated monitor)

Small Tower

Cost $1.6 million $750 $1595 ~$4000 $1000 - $2000

1990s: Pentiums and Power Macs

� Early 1990s began penetration of computers into every niche: every desk, most homes, etc.

� Faster, less expensive computers paved way for this

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this� Windows 95 was first decent GUI for “PCs”� Macs became more PC compatible - easy file

transfers

Fifth Generations 5. Ultra LARGE-SCALE INTEGRATED (USLI) 1991

� Microprocessor based� PROLOG may be used� Multimedia, KBS

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� Multimedia, KBS� Basic, Fortran, COBOL� KIPS, DIPS/LIPS� AI



IC1964-1975 VLSI

1975USLI 1991

Basic Components� Hardware� Software� Peripherals

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Basic Operations� Inputting� Storing� Processing� Outputting� Controlling

What Are The Primary Components Of A Computer ?

� Input devices.� Central Processing Unit (containing the control unit and the

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control unit and the arithmetic/logic unit).

� Memory.� Output devices.� Storage devices.� Power Supply Unit� Motherboard

Devices that comprise a computer system

Printer (output)

Monitor (output) Speaker

(output) System unit(processor, memory…)

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Scanner (input)

Mouse (input)

Keyboard (input)

Storage devices(CD-RW, Floppy, Hard disk, zip,…)

Input Devices� Keyboard.� Punch Card� Paper tape

Mouse.

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� Mouse.� Light pen� Touch screen� MICR (Magnetic Ink Character Recognition)� Bar Code Reader� OCR (Optical Character Recognition)

The KeyboardThe most commonly used input device is thekeyboard on which data is entered by manuallykeying in or typing certain keys. A keyboardtypically has 101 or 105 keys.

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The MouseIs a pointing device which is used to control themovement of a mouse pointer on the screen tomake selections from the screen. A mouse has oneto five buttons. The bottom of the mouse is flatand contains a mechanism that detects movement

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and contains a mechanism that detects movementof the mouse.

The Central processing UnitThe central processing unit (CPU) containselectronic circuits that cause processing to occur.The CPU interprets instructions to the computer,performs the logical and arithmetic processingoperations, and causes the input and output

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operations, and causes the input and outputoperations to occur. It is considered the “brain”of the computer.

MemoryMemory also called Random Access Memory orRAM (temporary memory) is the main memory ofthe computer. It consists of electroniccomponents that store data including numbers,letters of the alphabet, graphics and sound. Any

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letters of the alphabet, graphics and sound. Anyinformation stored in RAM is lost when thecomputer is turned off.Read Only Memory or ROM is memory that is etched on a chip that has start-up directions for your computer. It is permanent memory.

Amount Of RAM In ComputersThe amount of memory incomputers is typically measuredin kilobytes or megabytes. Onekilobyte (K or KB) equalsapproximately 1,000 memorylocations and one megabyte (Mor MB) equals approximately one

SIMM

DIMM

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locations and one megabyte (Mor MB) equals approximately onemillion locations A memorylocation, or byte, usually storesone character.Therefore, a computer with 8 MBof memory can storeapproximately 8 millioncharacters. One megabyte canhold approximately 500 pages oftext information.

SODIMM

What Does A Computer Do?Computers can perform fourgeneral operations, whichcomprise the information

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comprise the informationprocessing cycle.

� Input� Process� Output� Storage

Storage DevicesAuxiliary storage devices are used tostore data when they are not beingused in memory. The most commontypes of auxiliary storage used on

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types of auxiliary storage used onpersonal computers are floppy disks,hard disks and CD-ROM drives.

Floppy DisksA floppy disk is aportable, inexpensivestorage medium thatconsists of a thin,

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consists of a thin,circular, flexible plasticdisk with a magneticcoating enclosed in asquare-shaped plasticshell.

Structure Of Floppy Disks� A folly disk is a magnetic disk, which meansthat it used magnetic patterns to store data.

� Data in floppy disks can be read from andwritten to.

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written to.� Formatting is the process of preparing adisk for reading and writing.

� A track is a narrow recording band that formsa full circle on the surface of the disk.

� The disk’s storage locations are divided into pie-shaped sections called sectors.

� A sectors is capable of holding 512 bytes of data.A typical floppy stores data on both sides and has 80

Structure Of Floppy Disks

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� A typical floppy stores data on both sides and has 80tracks on each side with 18 sectors per track.

Hard Disks� A hard disk consists of one or more rigidmetal plates coated with a metal oxidematerial that allows data to be magneticallyrecorded on the surface of the platters.

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recorded on the surface of the platters.� The hard disk platters spin at a high rate ofspeed, typically 5400 to 7200 revolutions perminute (RPM).

� Storage capacites of hard disks for personalcomputers range from 10 GB to 120 GB (onebillion bytes are called a gigabyte).

Compact Discs� A compact disk (CD), also called an optical disc, is a

flat round, portable storage medium that is usually4.75 inch in diameter.

� A CD-ROM (read only memory), is a compact disc

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� A CD-ROM (read only memory), is a compact discthat used the same laser technology as audio CDs forrecording music. In addition it can contain othertypes of data such as text, graphics, and video.

� The capacity of a CD-ROM is 650 MB of data.

Output DevicesOutput devices make the informationresulting from the processing available foruse. The two output devices more commonlyused are the printer and the computerscreen.

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screen.The printer produces a hard copy of your output, and the computer screen produces a soft copy of your output.

Output devices

• Convert from electronic form to some other form

• May display the processed results

• Usable information

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Monitor or screen� Text� Numbers� Symbols� Art� Photographs� Video

Printer� Black and white� Color

• Usable information

Motherboard� Contains built-in electronic

components

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� All components like keyboard, mouse, printers and disk drives are attached.

Motherboard� Intel

� AMD Atholon

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� AMD Atholon

Power Supply Unit� The power supply is one of the

most important parts that needs to be understood. The power supply unit provides electrical power for

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unit provides electrical power for every component inside the system unit.

� The power supply plays the critical role of converting commercial electrical power (AC), into DC required by the components of the computer.

Power Supply Unit� There are two basic types of

power supplies:

AT power supplies –

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� AT power supplies –Designed to support AT-compatible motherboards.

� ATX power supplies –Designed according to newer ATX design specifications to support the ATX motherboard.

Printers� Impact Printer.- DOT matrix, Daisy

Wheel, Line � Non – Impact Printer – Laser, Ink jet

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� Non – Impact Printer – Laser, Ink jet� COM (Computer output to microfilm)

Data and Information� All computer processing requires data, which is a

collection of raw facts, figures and symbols, such asnumbers, words, images, video and sound, given tothe computer during the input phase.

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the computer during the input phase.� Computers manipulate data to create information.Information is data that is organized, meaningful,and useful.

� During the output Phase, the information that hasbeen created is put into some form, such as a printedreport.

� The information can also be put in computer storagefor future use.

Why Is A Computer So Powerful?� The ability to perform the information processing cycle with amazing speed.

� Reliability (low failure rate).

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� Accuracy.� Ability to store huge amounts of data and information.

� Ability to communicate with other computers.

How Does a Computer Know what to do?� It must be given a detailed list of instructions, called a compute program or software, that tells it exactly what to do.

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� Before processing a specific job, the computer program corresponding to that job must be stored in memory.

� Once the program is stored in memory the compute can start the operation by executing the program instructions one after the other.

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Computer Applications� Computer Assisted Instructions (CAI).� Computer Assisted Learning (CAL).� Computer Aided Learning & Teaching

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� Computer Aided Learning & Teaching� Medical