Introduction to Computers

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What is a computer?

• A computer is a electromechanical device which can be programmed to change (process) information from one form to another. – Do exactly as they are told.– Digital devices: Understand only two different states (OFF and

ON)

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First Generation – Vacuum Tubes• 1930’s – Vacuum tubes were used as electronic

circuits or electronic switches.

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First Generation – Vacuum Tubes• First electronic digital computer built by Konrad Zuse, who developed his first

machine, the Z1, in his parents' living room in Berlin in 1938. • Another early digital computer was built by Dr. John Atanasoff and his

assistant Clifford Berry, known as the ABC (Atanasoff Berry Computer) built at Iowa State University during 1937-42.

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1946 - ENIAC• First large-scale electronic digital computer was ENIAC (Electronic Numerical

Integrator and Calculator)• 30 feet long, 8 feet wide, and 8 feet high• 3 additions every second, (incredibly slow by today’s standards).

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1946 - ENIAC • Grace Hopper, one of the first

programmers on the ENIAC and the developer of the programming language COBOL, says, “It was the first machine that assisted the power of man’s brain instead of the strength of his arm.”

• ENIAC was developed long before the days of silicon chips or microchips, even before the transistor was invented.

• Like ABC, ENIAC was made up of vacuum tubes, over 18,000 of them!

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1951- UNIVAC 1 • 1951 the first commercially available computer was developed, the UNIVAC I

(UNIVersal Automatic Computer) using vacuum tubes• 3,000 additions every second. • In 5 years we were going a thousand times faster.

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1951- UNIVAC 1 • Rear Admiral Grace Hopper, USN, with other programmers. • Photo taken, August 13, 1957

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Second Generation – Transistors• 1947 - Walter Brittain and Willaim Shockley invented the

transistor at Bell Laboratories• Replaced the vacuum tube as an electronic switch

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1954 - TRADIC • TRADIC (TRAnsistorized Airborne DIgital Computer) • 800 transistors. • First computer system to completely use transistors

• First computer to be successfully operated in an aircraft, an environment which

was hostile to previous computer systems.

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Second Generation - TransistorsTransistors were:• Smaller• Faster• More reliable• Less expensive

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Third Generation – Integrated Circuits• 1959, Jack Kirby and Robert Noyce at Fairfield Semiconductor (who was later

to become the cofounder of Intel Corp.) developed the first integrated circuit (silicon chip or microchip).

• An integrated circuit (IC) is a system of interrelated circuits packaged together on a single sliver of silicon.

• It is a way of placing multiple (millions) transistor devices into as single, smaller device, the “microchip.”

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1960 – IBM 360• 1 addition every billionth of a second (nanosecond), or

a billion additions every second

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Third Generation – Integrated CircuitsICs, chips, were:• Smaller• Faster• More reliable• Less expensive

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Fourth Generation - Microprocessor• A microprocessor is a Central Processing Unit (CPU) on a single chip. • 1971, Intel Corp. introduced the first microprocessor chip. • Intel 4004• 108 kHz and contained (equivalent of) 2300 transistors

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IBM used it for calculators not computers• Busicom desk-top printing calculator, the world’s first commercial

product to use a microprocessor. • Used the Intel 4004 CPU.

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1975 - Altair 8800

• Ed Roberts and the first microcomputer or personal computer (for the consumer) the Altair 8800

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MITS Altair 8800• Microcomputer - a computer

which has a microprocessor. • Used the Intel 8080

Microprocessor

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Microprocessors

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1972 - Xerox Alto• Xerox Alto – first

microcomputer.• Developed at Xerox

PARC (Palo Alto Research Center)

• Not for consumer market.

• 1981 – Xerox Star• Xerox executives

“just didn’t get it”.

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1976 - Apple I• Steve Jobs and Steve Wozniak developed the Apple I microcomputer in their

basement. • Though it was a flop, its successor became the first popular home computer

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1977 – Apple II

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Others from 1977 - 1981Commodore PET 2001

Tandy TRS-80

Osbourne

Kaypro

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Others from 1977 - 1981Atari

Timex Sinclair

Texas Instruments

IMSAI

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1981 – IBM PC• What everyone was waiting for, or fearing…• “Open Architecture” and IBM

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1984 – Apple Macintosh

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1985 – Microsoft Windows 1.0

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1987 – IBM PS2 and OS2• Closed architecture (similar to Apple)• Never made it.

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Trends from 1990 to today…• Microsoft continues to develop and

improve Windows with latest version Windows XP and working on “Longhorn”

• LINUX operating system, an open source version of UNIX, is taking on MS Windows and gaining in popularity

• IBM has rebounded and continues to make personal computers, laptops, mainframes and minicomputers

• Apple continues to be a major player in personal computers, especially for the “creative market”, iPods, etc.

• Apple switching from IBM PowerPC CPU to Intel

• DELL, Compaq, Gateway, HP, IBM• Internet, networking, convergence

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Trends from 1990 to today…

• Faster• Smaller• More reliable• Less expensive• Easier to use

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Traditional Types of Computers

• General purpose computers–Mainframe–Minicomputer–Microcomputer (Personal Computer)

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Traditional Types of Computers

• First computers, introduced in 1950s • Used by large businesses • Typically supported 100 to 500 users• Very expensive• Used for very large processing tasks

• Mainframe Computers

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Traditional Types of Computers

• Typically supported 10 to 100 users • Smaller and less expensive than mainframes• The real difference is relative in terms of price, power,

marketing.

• Minicomputers

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Traditional Types of Computers

• Small, self-contained computers with their own CPUs

• Used by home and business users• Uses a microprocessor, a CPU

(Central Processing Unit) on a single chip.

• Microcomputers (Personal Computer or PC)

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Portable Computer

• Desktop computers• Laptop computers• Personal Digital Assistants (PDAs)

• What are these types of portable computers (a type of personal computer)?

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Networked computer• Networked computer = Computers connected to other computers or

peripheral devices (printers, etc.) to share information.• What is the difference between these two networked devices?

Intelligent terminal (computer) Dumb terminal

• No CPU (uses server’s)

• No Operating system (uses server’s)

• Input and Output only

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Embedded Computers• Embedded computers – Computers found in consumer goods in order

to enhance their function.

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Special Purpose Computers• Special purpose or dedicated computers – A device with a

specific purpose such as game system or information kiosk.

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Hardware versus Software• Hardware = The

physical components that make up a computer system.– More in a moment…

• Much more on all of these items in later presentations!

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Hardware versus Software• Software = The

programs (instructions) that tell the computer what to do.– System Software– Application Software– Stored on a storage

media such as hard disk, CD-ROM, floppy disk, tape, etc.

– More later…

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Hardware Components

• This is just an overview, more later…

Computers, throw away technology?

• When first developed digital computers were as large as a room and cost more than most large business could afford.

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Today systems costs have dropped to the level Today systems costs have dropped to the level where they are considered throw-away where they are considered throw-away technologytechnology

Computers, throw away technology?• Computer users fall roughly into two categories:

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Home users want a system that can plug in and use Internet (Wireless) E-Mail Games Learning (tutorials)

Home Use Business Use

Most home users do not know how to set up a computer system, and do not want to bother upgrading a system

Computers, throw away technology?

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• Business today rely on computers for at least some of their daily functions

• They view computers as a tool that helps their employees become more productive

• The cost of the computer is minor compared to the value it offers a company

System Safety

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Danger do not open there are no user serviceable parts inside. Refer

to qualified service technician.

System Safety

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• No exposed lethal voltage inside a PC

• Power Supply is completely enclosed in a sealed unit

• Some cases are stamped out of sheet metal and have sharp edges

System Safety

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• Static Electricity can cause serious damage to PCs• Facts about static electricity

- It takes approximately 3000 volts before a person can feel the effects - Walking across a carpet can generate as much as 35,000 volts - Walking on vinyl tile can generate 14,500 volts

- It takes approximately 30-50 volts to damage components

System Safety• Another major concern with computers is the

heat generated inside the case

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• Never place a computer against a wall with no air circulation• Remove dust from the inside of a system periodically• Route wires out of the way so airflow is not restricted inside

Timeline of Computer History

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http://www.computerhistory.org/timeline/?category=cmptr

http://www.computerhistory.org