History of the Computer

History of the Computer

History of the Computer• Mechanical Devices• Electro-Mechanical Devices• First Generation Computers• The Stored Program Concept

Mechanical Devices• Pascaline• Stepped Reckoner• Difference Engine• Analytical Engine

Pascaline• Invented in 1642 by Blaise

Pascal, a French mathematician.• Used a complicated set of gears.• Could only perform addition and

subtraction.• The Pascaline never worked as it

was designed to.

Pascaline


Stepped Reckoner• Invented by Gottfried Wilhelm

von Leibniz in 1674 a German mathematician.

• Performed addition, subtraction, multiplication, division, and calculated square roots(?).

• Frequently malfunctioned due to unreliable parts.

Stepped Reckoner


Difference Engine• Started by Charles Babbage in

1822.• Intended to calculate numbers to

20 decimal places.• Would have been used to

calculate navigational tables.• Never built, but led Babbage to

develop the Analytical Engine.

Difference Engine


Analytical Engine• Designed around 1833.• Used a set of instructions called

a program.• Included a memory unit.• Was never built.• Served as a model for modern

computers(?).

Analytical Engine, cont.• Ada Byron, Countess of Lovelace,

helped sponsor and aid Babbage in his work.

• Ada Bryon wrote a program for the Analytical Engine.

• Ada Byron said that she did not believe that the Engine could ever “originate anything.”

History of the Computer• Mechanical Devices• Electro-Mechanical Devices• First Generation Computers• The Stored Program Concept

History of the Computer:Electro-Mechanical

Devices• Hollerith’s Tabulating Machine• Mark I

Herman Hollerith’s Tabulating Machine

• Developed for the U.S. Census in 1890.

• Used electrical circuits rather than gears.

• Punched holes in cards represented information.

Herman Hollerith’s Tabulating Machine, cont.• When metal pins through holes

made contact, the counter was incremented.

• The general count was completed in six weeks.

Herman Hollerith’s Tabulating Machine, cont.

History of the Computer:Electro-Mechanical

Devices• Hollerith’s Tabulating Machine• Mark I

Mark I• Created by a team from IBM and

Harvard University.• The team was led by Howard

Aiken.• Data was input on punched

cards.• Used telephone relay switches to

store data.• Could not make decisions.

Mark I, cont.• Considered by many to be a

calculator and not a computer.• Over 51 ft long and weighed 5

tons.• Comprised of over 750,000 parts

making it unreliable.• Used to make range tables for

artillery during WWII.

Mark I, cont.

History of the Computer: First Generation

Computers• Mechanical Devices• Electro-Mechanical Devices• First Generation Computers• The Stored Program Concept

History of Computers:First Generation

Computers• Atanasoff-Berry Computer• ENIAC• Computer defined

Atanasoff-Berry Computer• First electronic computer.• Built between 1939 and 1942 at

Iowa State University by John Atanasoff and Clifford Berry.

• Used the binary (0s and 1s) number system.

Atanasoff-Berry Computer



ENIAC• Electronic Numerical Integrator

and Computer.• Like the Mark I, built to calculate

range tables for artillery shells.• Completed at the University of

Pennsylvania in 1946 by J. Presper Eckert and John Mauchly.

• Used 17,000 vacuum tubes which required special fans for cooling.

ENIAC



Computer• A computer is an electronic

machine that accepts data, processes it according to instructions (program), and provides the results as new data.

• A computer can make simple decisions and comparisons.

History of Computers: The Stored Program Computer• Mechanical Devices• Electro-Mechanical Devices• First Generation Computers• The Stored Program Computer

The Stored Program Computer

• Alan Turing and the “Universal Machine.”

• Program• CPU• EDVAC & EDSAC• Machine language• UNIVAC

Alan Turing and the “Universal Machine”

• Developed in the 1930s and 40s.• Machine would change tasks by

changing programs.• The “Universal Machine” was a

mathematical idea.• Alan Turing was a British

mathematician.

History of the Computer:The Stored Program

Computer• Alan Turing and the “Universal

Machine.”• Program• CPU• EDVAC & EDSAC• Machine language• UNIVAC

ProgramA program is a list of instructions written in a special language that the computer understands.




CPU• John von Neumann introduced

the idea of the stored program computer.

• Instructions would be stored in memory and executed in the CPU or Central Processing Unit.

• The CPU controlled the different functions of the computer electronically.




EDVAC & EDSAC• Electronic Discrete Variable

Automatic Calculator was built by Eckert, Mauchly, and von Neumann.

• Electronic Delay Storage Automatic Computer was built by Maurice Wilkes at Cambridge University in England.




Machine LanguageThe language that the computer understands. This language can represent switches as a series of 0s and 1s (0 is off and 1 is on).




UNIVAC• Universal Automatic Computer• Built by Eckert and Mauchly.• Sold to the Census Bureau in

1951.• All first generation computers

used vacuum tubes which made them large and expensive to purchase and run.

History of the Computer: Introducing the Computer• Second Generation

Computers• High-Level Programming

Languages• Third Generation Computers• Mainframes

Second Generation Computers

• Transistor• Model 650• Read, Write

Transistor• Invented by William Shockley,

John Bardeen, and Walter Brittain of Bell Laboratories.

• Made computers smaller and less expensive.

• Increased calculating speeds.



Model 650• Introduced by IBM in the early

1960s.• Purchased by government and

business organizations.• Popular in spite of its cost.



Read, Write• Magnetic tape and reel-to-reel

tape machines began to be used to store and retrieve data and instructions.

• Magnetic tape made data storage and retrieval much faster.

• Punched cards were still in use, not replaced.

Read, Write, cont.

History of the Comuter: Introducing the Computer• Second Generation



High-Level Programming Languages

• Need for• FORTRAN• COBOL/Ada• BASIC• C• C++• Java

Need For• Machine language programs are

hard to write.• High-Level languages use

English-like statements that are easier to understand.



FORTRAN• Formula Translator or FORTRAN

was developed in 1957 by John Backus. Used commands such as “READ” and “WRITE”.

• Use primarily for scientific and engineering purposes.



COBOL• COmmon Business Oriented

Language was developed by Grace Murray Hopper for the Department of Defense in 1959.

• Ada was also developed by the DOD and named after Ada Byron.


• Need for• FORTRAN• COBOL• BASIC• C• C++• Java

BASIC• Beginners All-purpose Symbolic

Instruction Code or BASIC was developed at Dartmouth University in the early 1960s by John Kemeny and Thomas Kurtz.

• Developed as a language for teaching computer programming.

• Has evolved into Visual Basic (a Microsoft product).


• Need for• FORTRAN• COBOL• BASIC• C• C++• Java

C/C++/Java• C was developed to create the

UNIX operating system.• C++ was developed to use a

new programming philosophy called Object Oriented Programming.

• Java is an Object Oriented programming language mainly used for device programming.

History of Computers: Introducing the Computer• Second Generation



Third Generation Computers

• Integrated Circuits• IBM System 360

Integrated Circuits• The IC or chip replaced

transistors just as transistors replaced vacuum tubes.

• Independently invented by Jack Kilby and Robert Noyce in 1961.

• ICs are silicon wafers with circuits etched in their surface.

Third Generation Computers

• Integrated Circuits• IBM System 360

IBM System 360• One of the first computers to use

ICs.• Relatively inexpensive; allows

smaller businesses and universities to purchase computers.

History of Computers: Introducing the Computer• Second Generation



Mainframesa. Definitionb. IBM System 360c. Used. Terminals

Definition of a MainframeA mainframe is a large computer system that is usually used for multi-user applications.

Mainframes• Definition• IBM System 360• Use• Terminals

IBM System 360The IBM System 360 was one of the first mainframes available.

STOP

History of Computers: Introducing the Computer• Fourth Generation Computers• The Personal Computer• Memory: ROM and RAM• The CPU• Bits and Bytes

Fourth Generation Computers

• Microprocessor• Microcomputer

Microprocessor• Invented by Marcian Hoff at Intel

Corporation.• Places an entire CPU on a chip.• Made possible the fourth

generation of computers.

Fourth Generation Computers

• Microprocessor• Microcomputer

Microcomputer1) Made possible by the

microprocessor.2) Fits on a desk and are now

usually called personal computers.

3) First was the Altair built in 1975.4) In 1976 Stephen Wozniak and

Steven Jobs designed and built the first Apple computer.

History of the Computer: Introducing the Computer9. Fourth Generation

Computers10. The Personal Computer11. Memory: ROM and RAM12. The CPU13. Bits and Bytes

The Personal Computer1) Often called “PC” which is

usually associated with “IBM compatible” PC.

2) “Mac” is short for Macintosh which is an Apple product.

3) Personal computers contain four types of hardware components.

4) Data flow diagram






Hardware Componentsa) Input devices – Allows the

computer to accept data: keyboard, CD-ROM drive, disk drive, mouse, etc.

b) Memory – Integrated circuits within the base unit that is used to store data.

Hardware Componentsa) CPU(Central Processing Unit) –

An IC within the base unit that processes data and controls the flow of data between the computer’s other units.

b) Output Devices – Devices that display or store processed data: monitors, printers, disk drives, etc.






Data Flow Diagram

Input Memory

CPU

Output

Chapter I: Introducing the Computer

9. Fourth Generation Computers

10. The Personal Computer11. Memory: ROM and RAM12. The CPU13. Bits and Bytes

Memory: ROM and RAMa. ROMb. RAM


ROM1) ROM: Read-Only-Memory2) Contains basic operating

instructions for the computer (Basic Input Output System or BIOS).

3) The instructions stored in ROM are not lost when the computer is turned off.


RAM1) Random Access Memory2) Temporary memory where

programs and data are stored.3) The contents of RAM may be

changed.4) Anything left in RAM when the

computer is turned off is lost and cannot be retrieved.




The CPUa. CPU – Central processing unitb. Directs the processing of

information throughout the computer.

c. Executes instructions received from RAM or ROM.

d. Contains the ALU (Arithmetic Logic Unit).




Bits and Bytesa. Binaryb. Bit/bytec. ASCIId. Memory Size


Binary1) Data is manipulated within a

computer by turning switches on or off. On can be represented by the digit 1 and off by the digit 0.

2) This makes the binary number system ideal for mathematically representing the internal workings of a computer.


Bit/Byte1) Bit stands for BInary DigiT.2) Eight bits make one byte.


ASCII1) American Standard Code for

Information Interchange.2) Developed in the early 1960s to

allow computers to exchange information.

3) Each character and control function is assigned a value between 0 and 127.

ASCII, cont.

Letter Decimal Binary

A 65 1000001

$ 36 0100100

cr 13 0001101


Memory Size1) The size of a computer’s

memory is measured in bytes.2) Suffixes are used to make the

numbers more manageable:K(b) – kilobyte (1,024)mb – megabyte(1,048,576)gb – gigabyte (1,073,741,824)tb – terabyte (1,099,511,627,776)


14. Storage Devices15. Peripheral Devices

Storage Devicesa. (floppy) Disketteb. Hard drivec. CD-ROM (RW)d. DVD-ROMe. USB Mass Storage

(floppy) Diskette1) Called a “floppy” because the

platter inside is floppy plastic covered with ferrous oxide (rust).

2) Data is stored magnetically like songs are stored on cassette tapes.

3) Can usually store 1.44 mb of data.


Hard Drive1) Called a hard drive because the

platters are hard not floppy.2) Can store thousands or hundreds

of thousands times more data than a floppy diskette.

3) Data is still stored magnetically.


CD-ROM (RW)1) Data is stored in such a way that

it can be retrieved with laser light.

2) A CD-ROM can hold approx. 650 mb of data.

3) A CD-RW can be used like a floppy diskette. Data on the diskette can be changed.


DVD-ROM1) Same as CD-ROM only bigger.2) Can store approx. 4.7 gb of data.


USB Mass Storage1) Uses “flash memory” for storage.2) Available from 16mb to 2gb.3) Uses USB connector.


14. Storage Devices15. Peripheral Devices

Peripheral Devicesa. Printersb. Scanners

Printers1) Dot matrix (nearly obsolete)2) Inkjet (mainstream printer)3) Laser (common)4) Color Laser (getting cheaper)5) A printer is also an output

device.

Peripheral Devicesa. Printersb. Scanners

Scanners1) Used to input pictures or

documents as images.2) Is also an input device.


16. Telecommunication17. Networks18. Network Services19. Using a Network20. The World Wide Web

(WWW)21. The Software Revolution

History of the Computer

Documents

clifford berry

ada byron

punched cards

punched holes

modern computers

ada bryon

charles babbage

unreliable parts