CSCI-235 Micro-Computer in Science Introduction. Course Overview Class webpage ltyang/csci-235/ ltyang/csci-235

CSCI-235CSCI-235Micro-Computer in ScienceMicro-Computer in Science

IntroductionIntroduction

Course OverviewCourse Overview

Class webpageClass webpage http://cs.stfx.ca/~ltyang/csci-235/

© Prentice-Hall, Inc

What Is a Computer?What Is a Computer?

A machine that can be programmed to A machine that can be programmed to accept data, process it into useful accept data, process it into useful information, and store it awayinformation, and store it away DataData

• raw facts representing people and eventsraw facts representing people and events InformationInformation

• data that is organized, meaningful, and usefuldata that is organized, meaningful, and useful


The Processing Cycle of a The Processing Cycle of a ComputerComputer

A Brief History of the ComputerA Brief History of the Computer

First “computer”?First “computer”? The first actual calculating mechanism known The first actual calculating mechanism known

to us is the abacus, which was invented about to us is the abacus, which was invented about 2000 years ago2000 years ago

Abacus: The art of calculating with beadsAbacus: The art of calculating with beadsAdapted From: http://www.maxmon.com/history.htm


Many references cite the French Many references cite the French mathematician, physicist, and mathematician, physicist, and theologian Blaise Pascal as being theologian Blaise Pascal as being the inventor of the first mechanical the inventor of the first mechanical calculator in 1642, the Arithmetic calculator in 1642, the Arithmetic Machine Machine

Adapted From: http://www.maxmon.com/history.htm


However, it now appears that the first mechanical However, it now appears that the first mechanical calculator may have been conceived by calculator may have been conceived by someone else almost 150 years earlier than someone else almost 150 years earlier than Pascal's machine. Can you guess who?Pascal's machine. Can you guess who?

Leonardo Da VinciLeonardo Da Vinci



In the early 1800s, a French silk weaver called In the early 1800s, a French silk weaver called Joseph-Marie JacquardJoseph-Marie Jacquard invented a way of invented a way of automatically controlling the warp and weft automatically controlling the warp and weft threads on a silk loom by recording patterns of threads on a silk loom by recording patterns of holes in a string of cards holes in a string of cards



The first device that might be considered The first device that might be considered to be a computer in the modern sense of to be a computer in the modern sense of the word was the Difference Engine to the word was the Difference Engine to automatically calculate mathematical automatically calculate mathematical tables conceived in 1822 by the British tables conceived in 1822 by the British mathematician and inventor mathematician and inventor Charles Charles BabbageBabbage



The Difference Engine was only partially The Difference Engine was only partially completed when Babbage conceived the completed when Babbage conceived the idea of another, more sophisticated idea of another, more sophisticated machine called the Analytical Engine machine called the Analytical Engine

The Analytical Engine was intended to use The Analytical Engine was intended to use loops of Jacquard's punched cards to loops of Jacquard's punched cards to control an automatic calculator, which control an automatic calculator, which could make decisions based on the results could make decisions based on the results of previous computationsof previous computations



Working with Babbage was Working with Babbage was Augusta Ada Augusta Ada LovelaceLovelace, the daughter of the English poet , the daughter of the English poet Lord Lord ByronByron. Ada, who was a splendid mathematician . Ada, who was a splendid mathematician and one of the few people who fully understood and one of the few people who fully understood Babbage's vision, created a program for the Babbage's vision, created a program for the Analytical EngineAnalytical Engine

Ada is now credited as being the first computer Ada is now credited as being the first computer programmer and, in 1979, a modern programmer and, in 1979, a modern programming language was named programming language was named ADAADA in her in her honorhonor




In 1939, a German engineer, Konrad Zuse built the first programmable, general-purpose digital computer. His computer was built from electric relays to automate engineering calculations

“I was too lazy to calculate and so I invented the computer.”



John Atanasoff invented the Atanasoff-Berry Computer (ABC) —the first electronic digital computer. Built in 1939, this computer used vacuum tubes and was based on binary arithmetic. It was never a fully operational product.



In 1944, Howard Aiken completed the Mark I, the largest electromechanical calculator ever built. It was built with electromechanical relays and followed instructions punched in paper tape



The first computer “bug”The first computer “bug”



In 1945, Mauchly and Eckert built the ENIAC (Electronic Numerical Integrator and Computer). The ENIAC was built with 18,000 vacuum tubes that failed on an average of once every seven minutes

After the war, they created the UNIVAC I - the first general-purpose commercial computer


First-Generation ComputersFirst-Generation Computers

1930s – 1940s1930s – 1940s Vacuum tubes used as switchesVacuum tubes used as switches Large computersLarge computers Extremely slow by today’s standardsExtremely slow by today’s standards Prone to frequent failureProne to frequent failure Includes the ABC, Mark I, ENIAC, UNIVAC,Includes the ABC, Mark I, ENIAC, UNIVAC,

and others of similar designand others of similar design


Second-Generation Second-Generation ComputersComputers

1950s – mid-1960s1950s – mid-1960s Transistors used as switchesTransistors used as switches Smaller than vacuum-tube-built computersSmaller than vacuum-tube-built computers As much as a thousand times faster than As much as a thousand times faster than

first-generation computersfirst-generation computers More reliable and less expensiveMore reliable and less expensive


Third-Generation ComputersThird-Generation Computers

Late 1960sLate 1960s Hundreds of transistors packed into a single Hundreds of transistors packed into a single

integrated circuit on a silicon chipintegrated circuit on a silicon chip Dramatic reduction in size and costDramatic reduction in size and cost Significant increases in reliability, speed, Significant increases in reliability, speed,

and efficiencyand efficiency Mass production techniques to manufacture Mass production techniques to manufacture

chips inexpensivelychips inexpensively


Fourth-Generation ComputersFourth-Generation Computers

1970s to present1970s to present

Complete computer on a Complete computer on a chipchip

Radical change in the Radical change in the appearance, capability appearance, capability and availability of and availability of computerscomputers


Computer System ComponentsComputer System Components

HardwareHardware Equipment associated with the systemEquipment associated with the system

SoftwareSoftware Instructions that tell the hardware what to doInstructions that tell the hardware what to do

PeoplePeople Computer programmer: writes softwareComputer programmer: writes software User: purchases and uses softwareUser: purchases and uses software

• Often called end-userOften called end-user


Hardware: The Basic Components Hardware: The Basic Components of a Computerof a Computer

Four primary Four primary components:components: Input DevicesInput Devices ProcessorProcessor Output devicesOutput devices StorageStorage


Input Devices: KeyboardInput Devices: Keyboard

Most common input deviceMost common input device Generates electrical signals Generates electrical signals

which are translated into which are translated into characterscharacters


Input Devices: MouseInput Devices: Mouse

Moves over a flat surfaceMoves over a flat surface Movement of mouse ball causes corresponding Movement of mouse ball causes corresponding

movement of pointer on screenmovement of pointer on screen


The ProcessorThe Processor

Also called central processing unit (CPU)Also called central processing unit (CPU) Center of activity in the computerCenter of activity in the computer

Consists of electronic circuits Consists of electronic circuits • Interprets and executes program instructionsInterprets and executes program instructions• Communicates with input, output, and storage Communicates with input, output, and storage

devicesdevices

Actually transforms data into informationActually transforms data into information


Storage: Primary StorageStorage: Primary Storage

Used to temporarily hold dataUsed to temporarily hold data After it is retrieved from input device and After it is retrieved from input device and

before it is processedbefore it is processed After it is processed and before it is released After it is processed and before it is released

to output deviceto output device Temporary (volatile) storageTemporary (volatile) storage

Data in memory lost if power is lost or Data in memory lost if power is lost or program closedprogram closed


Storage: Secondary StorageStorage: Secondary Storage

Provides long-term storageProvides long-term storage Separate from memorySeparate from memory

Common mediaCommon media Magnetic disksMagnetic disks Optical disksOptical disks Magnetic tapeMagnetic tape


Magnetic DisksMagnetic Disks

The most common storage mediaThe most common storage media Diskette: 3.5” flexible diskette in plastic caseDiskette: 3.5” flexible diskette in plastic case Hard Disk: more storage capacity and faster Hard Disk: more storage capacity and faster

access than disketteaccess than diskette


Optical DisksOptical Disks

Use a laser beam to read large volumes of Use a laser beam to read large volumes of data inexpensivelydata inexpensively CD-ROMsCD-ROMs DVD-ROMsDVD-ROMs


Magnetic TapeMagnetic Tape

Stores large amounts of data Stores large amounts of data inexpensivelyinexpensively

Often used for system backupOften used for system backup


SoftwareSoftware All the programs that give the computer its All the programs that give the computer its

instructionsinstructions Two categories of software:Two categories of software:

System software Application softwareSystem software Application software

Documents

CSCI-235 Micro-Computer in Science Introduction. Course Overview Class webpage ltyang/csci-235/ ltyang/csci-235