Computers What is it? History, Moore’s Law How to build your own? Sohaib Ahmad Khan CS101 - Topical Lecture

What is a computer? Input Processing Output

Is the Abacus a Computer? Not really a computer, but rather a computing aid

Slide Credit: Prof Slotterbeck, Hiram College Intricate textile patterns were prized in France in early 1800s. Jacquard’s loom (1805-6) used punched cards to allow only some rods to bring the thread into the loom on each shuttle pass. Jacquard Loom - A mechanical device that influenced early computer design

Sheets of punched cards set the pattern of the weave Slide Credit: Prof Slotterbeck, Hiram College

How Can You Make Your Own Computer? Using ‘Buntas’

The ‘Bunta’ Switch Input Output InputOutput 00 11

Two ‘Bunta’ Switches Input 1 Output Input 2 Input 1 OutputInput

Two ‘Bunta’ Switches Input 1 Output Input 2 Input 1 OutputInput

Two ‘Bunta’ Switches Input 1 Input 2 Input 1 OutputInput Output 111 AND Operation

Other Operations with two switches 1 st number 2 nd number Result OR Operation 1 st number 2 nd number Result XOR Operation

How to make your own computer How to make an adder? How to make an adder? –Because an adder can be used to make a multiplier To keep things simple, lets talk BINARY To keep things simple, lets talk BINARY 1 st Number2 nd NumberResultCarry

1-Bit Binary Adder 1 st number 2 nd number ResultCarry Carry Result Input 1 Input 2 AND XOR

Summary Using adders, I can make a large computer Using adders, I can make a large computer I can make adders using switches I can make adders using switches The output of one switch should be able to toggle another switch The output of one switch should be able to toggle another switch –Because I may want to use lots of switches in a cascade

The ‘Bunta’ Argument A computer is just a whole lot of adders put together… A computer is just a whole lot of adders put together… I can make a an adder using ‘buntas’ I can make a an adder using ‘buntas’ Therefore, I can make a computer using ‘buntas’ Therefore, I can make a computer using ‘buntas’

Really Large ‘Bunta’ Computer: The Buntium TM Pentium 4 has about 40 million switches in it Pentium 4 has about 40 million switches in it Suppose I can make a ‘bunta’ switch in a 25 cm 2 area Suppose I can make a ‘bunta’ switch in a 25 cm 2 area Lets put 30% overhead for inter-connections between switches Lets put 30% overhead for inter-connections between switches Then I need 1.3 billion cm 2, or 130,000 m 2 area… Then I need 1.3 billion cm 2, or 130,000 m 2 area… Other Ideas: I can also make a computer from water pipes and valves… or light switches… or… Other Ideas: I can also make a computer from water pipes and valves… or light switches… or…

Charles Babbage Babbage is known as the father of modern computing because he was the first person to design a general purpose computing device. Babbage is known as the father of modern computing because he was the first person to design a general purpose computing device. In 1822, Babbage began to design and build a small working model of an automatic mechanical calculating machine, which he called a "difference engine". In 1822, Babbage began to design and build a small working model of an automatic mechanical calculating machine, which he called a "difference engine". Example: It could find the first 30 prime numbers in two and a half minutes. Example: It could find the first 30 prime numbers in two and a half minutes. Source: line/babbage/page3.asp, Slide Credit: Prof Slotterbeck, Hiram Collegehttp:// line/babbage/page3.asp In the Science Museum, London

source: Slide Credit: Prof Slotterbeck, Hiram College The Analytical Engine The machine was to operate automatically, by steam power, and would require only one attendant.

Curta Pocket Calculators Mechanical Calculator that can do complex operations Mechanical Calculator that can do complex operations Circa 1960’s Circa 1960’s Went out of production with the advent of the electronic calculator Went out of production with the advent of the electronic calculator

Advent of Modern Computing Vacuum Tubes Vacuum Tubes Transistors Transistors

ENIAC – (Electrical Numerical Integrator And Calculator), built by Presper Eckert and John Mauchly at Moore School of Engineering, University of Pennsylvania, Often called the first computer (that was electronic, programmable, general purpose and digital).

ENIAC 18,000 vacuum tubes and weighed 30 tons 18,000 vacuum tubes and weighed 30 tons Duration of an average run without some failure was only a few hours, although it was predicted to not run at all! Duration of an average run without some failure was only a few hours, although it was predicted to not run at all! When it ran, the lights in Philadelphia dimmed! When it ran, the lights in Philadelphia dimmed! ENIAC Stored a maximum of twenty 10-digit decimal numbers. ENIAC Stored a maximum of twenty 10-digit decimal numbers. Input: IBM card reader Input: IBM card reader Output: Punched cards, lights Output: Punched cards, lights

ENIAC Programming required rewiring of the machine, Source:

Early Microprocessor Intel 8080, 1975, 4500 transistors Intel 8080, 1975, 4500 transistors

Moore’s Law Stated in 1965 Stated in 1965 Not a real law Not a real law “The number of transistors on a chip roughly doubles every two years” “The number of transistors on a chip roughly doubles every two years” “The cost of making a transistor on a chip roughly halves every two years” “The cost of making a transistor on a chip roughly halves every two years”

The Pentium 4, which debuted in 2000, sported 42 million transistors. Dual- core Itaniums have more than a billion. Credit: Intel

ftp://download.intel.com/museum/Moores_Law/Printed_Materials/Moores_Law_Backgrounder.pdf

ftp://download.intel.com/museum/Moores_Law/Printed_Materials/Moores_Law_2pg.pdf

Reading Assignment Chapter 1 and Chapter 2 of text Chapter 1 and Chapter 2 of text