Computer History

Early Calculating Devices

People have been using devices to aid in calculation for thousands of years.

Devices include

◦ fingers

◦ tally sticks (animal bones carved with notches)

◦ counting rods ( I, II, III, IIII, IIIII, T)

◦ the abacus, ...

Abacus

appeared in 2700-2300BC, It’s a counting device, Beads are moved to perform arithmetic functions, Still used by traders and clerks in Asia, Africa, ...

Slide Ruler

An early analogue computer used primarily for multiplication and division. Invented by William Oughtred in 1620. It was taken to the moon in the 1960s

Pascaline

Blaise Pascal created the first mechanical calculator in 1642. Performed addition and subtraction. Was too expensive for the time, hence it didn’t become a commercial

device.

Charles Babbage

• Noticed errors in mathematical tables (1820). Created the difference engine to compute this math more accurately.

• Used tons of grant money as well as his own.

• Only built a small part, as he also had to construct the tools to build it

• The difference engine wasn’t finished, and he went on to design the Analytical engine.

Difference Engine

• The first mechanical computer Created by Charles Babbage a “father of computing” in 1821.

• Compiled mathematical tables ◦ add, subtract, polynomial functions

Ada Lovelace

• She wrote the first algorithm that would have been executed by the Analytical Engine

• She is considered the worlds first programmer

Punch Cards

• Stiff paper that holds commands.

• Commands and data are indicated by holes/no holes.

• Early computers used these as input commands

Herman Hollerith

• During the Industrial revolution the population 30% each decade. They were still tabulating census data by hand. In 1887 they still had not completed tallying the 1880 census data

• An MIT prof introduced punch cards and a machine to read them to tally this information.

• Took only 6 weeks to tally the 1890 census He continued to improve the machine, and created the company IBM

1st Generation Computers

• 1951 – 1959

• Based on Vacuum tubes.

• Vacuum tubes: Control electric current using the vacuum

• Can be used to start/stop, or change the flow based on the current.

Alan Turing

• During WWII ____ created an electromechanical machine to break German Ciphers.

• It is estimated that his efforts in breaking the ciphers reduced the length of the war by 2 – 4 years.

Harvard Mark 1

• A electro-mechanical computer Created by Howard Aiken and Grace Hopper Developed and built by IBM introduced in 1944.

• It Could store 72 numbers Multiplication took 6 seconds Used in WW II to compute artillery tables Produced Mathematical Tables

First Computer Bug

• Grace Hopper found the _____ while working on the Harvard Mark II in 1947.

• A moth was trapped between two relay switches She took a photo to document it

ENIAC

• First electronic general purpose computer Created at the University of Pennsylvania

• Cost almost $500,000 (approx. $6,000,000 today)

• One of first programs a study of the hydrogen bomb A secret military project designed to improve the construction of artillery firing tables

• 1946

• Contained 17,500 Vacuum tubes 7,200 crystal diodes,

• Tubes burnt out fast, hence the machine normally could only run for

• 10 to 30 minutes at a time

• Speed was 1000 times of electro-mechanical machines (Wikipedia)

• 5000 adds, 357 multiplications, and 38 divisions per minute

Electronic Numerical Integrator and Computer

What is the meaning of ENIAC?

UNIVAC

• Inventors of ENIAC made ___ which is a programmable (held data and printed)

• Few people bought it as they didn’t understand the value

• Then they used it to project the 1952 presidential election, and it got the answer with <1% error

2nd Generation Computers

• Based on Transistors

• 1959-1965

• Stored instructions in memory

• Relied on punch cards for input and printers for output

Transistors

• Replaced vacuum tubes

• Invented at Bell laboratories

• Enabled computers to be smaller, cheaper, more reliable, and efficient

• Works as switches on current, turning it on or off (like binary 0 or 1).

• Still generate a lot of heat, but less than vacuum tubes

IBM 1400

• Introduced in 1960

• General purpose system

• Used punch cards for input and line printer for output

3rd Generation Computers

• Modern computers

• 1965-1971

• Used Integrated Circuits

• Keyboards instead of punch cards

• Monitors for display

• Different applications used through operating system

Integrated Circuits

• Small chips containing thousands of transistors

• Invented by Jack Kilby, Nobel Laureate of Physics

IBM 360

• Introduced in 1964

• Small and large applications

• Commercial and Scientific applications

• From 8Kb to 8Mb of memory

• Room sized

• A whole suite of compatible computers for different needs

4th Generation Computers

• Microprocessor

• Development of the personal computer

• 1971 – 1981

• Addition of GUI’s, the mouse, and handheld devices

Microprocessor

• Thousands of Integrated Circuits were built on a silicon chip.

• Created by Intel corp.

• Becomes the Central Processing Unit (CPU)

• Allow computers to be smaller, more powerful, faster, and cheaper

Altair 8080

• 1975

• First personal computer

• Make it yourself kit

• Switches for input, lights for output

• No keyboard, and no monitor

• People were so excited, within 3 months 4000 orders were placed

• Gates and Allen were trying to meet with MITS founder who created the Altair

• They built an interpreter for the 8080 to make programming software for the machine easier.

• Allen created a Bootstrapper to load the tape to load the program on a plane ride on final approach to their meeting

Apple I and II

• 1976

• Steve Wozniak and Steve Jobs built the ____ in Wozniak’s garage ____ had a color monitor, sound, and game paddles

IBM PC

• 1981

• IBM released it’s first personal computer

• Sold in companies such as Sears

Beginners All-Purpose Symbolic Instruction Code

What is the meaning of the acronym “BASIC”

BASIC

• Beginners All-Purpose Symbolic Instruction Code

• A programming language that students could learn

• Used by Bill Gates and Paul Allen to write a program for the Altair

MS-DOS (Disc Operating System)

• IBM hired Bill gates and Paul Allen to build an Operating System for the

• IBM PC

• They bought the rights to an existing operating system built in Seattle

• IBM allowed Gates and Allen to keep the marketing rights to DOS

Reverse Engineering

• Companies like Compaq took apart IBM computers, and ______ their BIOS to create very similar machines.

• They built a fully compatible machine, and sold it for a bit cheaper.

• In first year they sold 47,000 pcs and made 111 million dollars

• Hence, the competition began And everyone bought Microsoft OS

Spreadsheets and Word Processing

In 1978 VisiCalc was created for Spreadsheets and WordStar was created for Word Processing

Graphical User Interface (GUI)

• In 1972 Apple and Xerox were working on making a graphical user interface

• WYSIWIG (What you see is what you get)

• The idea being you want to be able to preview your work on the computer

Apple’s 1984 Commercial

As Microsoft was aiming their products towards business users, apple tried to make the first user friendly PC. This commercial was fighting out against IBM which they saw as Big Brother

5th Generation Computers

• 1990 - Present

• Enhancement of Artificial Intelligence

• Nanotechnology

• Natural Language Processing