Lecture-03

• PC History

Evolution of Computer s

• Mechanical Calculators

• Mechanical Computers

• Electronic Computers– Tubes– Transistors– ICs

Highlights

“Napiers Bones” for calculating

• 1617 “Napiers Bones” was the starting point that lead to the search for a better way to achieve mathematical calculations. – John Napier created “Napiers Bones” for

calculating. – Similar to abacus.

digital adding machine

• 1642– Blaise Pascal introduced Pascaline digital

adding machine.– First adding machine.– Could add numbers entered on dials.

calculator capable multiplying

• 1671– Gottfried Wilhelm von Leibniz invented a

calculator capable of adding and multiplying.

– It was built in 1694.

first successful mechanical calculator

• 1820– Charles Xavier Thomas developed first

successful mechanical calculator that was capable of adding, subtracting, multiplying and dividing.

Calculator

Mechanical Computers

• 1822– Charles Babbage (father of computers)

invents the Difference Engine.• Solved polynomial equations.• Steam-powered and capable of printing results

Father of computers

program-controlled, mechanical computer

• 1833– Charles Babbage designed a general-

purpose, program-controlled, automatic mechanical computer.

Never built

– Called the Analytical Engine.– Capable of working on 50 digit numbers with a storage

capacity of 1,000 50 digit numbers.– Input would have been accomplished through punch cards.– Considered first true general purpose computer.– Would have included:

Input device Control unit

Processor Storage

Output device

– Never built because intricate gear and mechanisms could not be built.

Punch cards & IBM

• 1890– Punch cards developed by Herman

Hollerith for input and storage.– Herman later founded Tabulating Machine

Company, also known as IBM.

vacuum tube

• 1906

Deforest invents a vacuum tube that later serves as one of the first types of electronic switches in a computer circuit.

binary numbers

• 1937

Iowa State College professor invents the base-two (binary) numbers instead of the traditional base ten.

Bits - Short for “Binary Digits”

First electronic digital computer

• 1942– First digital computer created by a

physicist, John V. Atanasoff using vacuum tubes (patented in 1906) as switches.

Stored-program technique

• 1945– John Von Neumann demonstrated that

computers did not needed to be rewired to enter a new program.

– Stored-program technique became fundamental for future generations of high-speed digital computers.

Transistorised Computers

• 1947– First transistors developed.– The invention of the transistor that lead

revolution to the miniaturization of circuitry.

– EDVAC and UNIVAC computers appeared.• They did not need to be rewired for new

programs.• Used RAM.

First large scale electronic computer

• 1946– First large scale electronic computer built for the

military.– ENIAC, Electrical Numerical Integrator and

Calculator• Operated on 10 digit numbers, could multiply two such numbers 300 times a

second by finding the value of the product from a multiplication table stored in memory.

• Used 18,000 tubes, needed 1,800 square feet of space, consumed 180,000 watts of power.

• Punch cards used for input and output.

• Registers used for adders and quick-access storage.

• Programs were entered into ENIAC by rewiring it.

Integrated circuit Computers

• 1959– Integrated circuit developed.– Texas Instruments invented the IC

(Integrated Circuit)– Third generation computers were born.

First microprocessor 4004

• 1971– First microprocessor.– 4-bit Intel 4004– Smaller than a thumbnail, with 2300

transistors on board.– As powerful as the first electronic

computer, ENIAC and cost $200.

First personal computer

• 1975– First personal computer sold, Altair.– Used CP/M (Control Program for

Microprocessors) and BASIC language.

Computers Kit

• 1975

MITS introduced the “Altair” featuring an 8080 processor and 256 Bytes of memory for $395.

First Personal Computers

• 1975

IBM introduced the”Model 5100” with 16 Kilobytes of memory for $9,000.

Apple Computers

• 1976

Apple introduced the “Apple I” for $666.

• In the 1980’s,

Apple was the primary dominating force behind PCs.

IBM started developing personal computers

• End of 1980– IBM started developing personal

computers.– Contracted out operating system and

software development to a small company, Microsoft.

The IBM Personal Computer

• Wednesday, August 12th, 1981, IBM changed the face of computing by releasing the “IBM PC”

• Digital Research was originally contacted to write the OS (Operating System) but balked.

• A small, fledgling company named Microsoft eagerly took up the task

What is a PC?

• “IBM Compatible” or “Clone”

• Who controls Hardware and Software?

• Microsoft was free to sell their OS (DOS) to anyone, making IBM clones seemingly identical to their competition

IBM compatibles

• Now– IBM compatibles made and improved by

hundreds of companies.– Apple Macintosh is a closed system and

they control the primary system software.

What is a PC?

• Intel is the leader in PC processors

• Intel develops chipsets to support their processors

• Intel develops new expansion buses such as PCI and AGP

• Intel makes motherboards for leading vendors such as Dell and Gateway

System Types

• 8 Bit

• 16 Bit

• 32 Bit

• 64 Bit

• PC/XT systems

• AT systems

• ATX systems

System Types

• PC - Personal Computer

• XT systems - Extended Systems (PC + HD)

• AT systems - Advanced Technology 16 bits

• Shape, layout, Power supply brought different Form Factors:

PC/XT, AT, AT/Desk, AT/Tower, Baby-AT, LPX, ATX, NLX, SFX, ATX Auxiliary, ATX12V, ATX Optional, Dell Proprietary ATX

Moore’s Law

• Each new chip contains roughly twice as much capacity as its predecessor, and each new chip is released with 18-24 months. Computing power is rising exponentially over a brief period of time.

10M(transistors)

1M

100K

10K

1975 1980 1985 1990 1995

4004

8080

8086

80286

80386

80486

Pentium, 66MHzProcessor, 1993, 5.5 M

PII, 350 MHz1999, 27 M 500

(MIPS)

25

1.0

0.1

0.01

2000 2005

P4A, 2,5 GHz2002, 55 M

20 nm, 20GHz2007, 1000 M