Lecture Notes: Computers in the Modern Age

Introduction

• Discusses the evolution and impact of computers over different generations.

Generations of Computers

First Generation: Vacuum Tubes

• Early computers like ENIAC and UNIVAC used vacuum tubes.
• Vacuum tubes were also used in TVs and radios.
• High power consumption and heat generation were major issues.
• Vacuum tubes invention: 1904, widespread use around 1910.
• Significant use during WWII.

Second Generation: Transistors

• Transistors replaced vacuum tubes.
• Advantages: smaller size, less power consumption.

Third Generation: Integrated Circuits

• Separate transistors wired into computers.
• Integrated directly into circuit boards.
• More powerful and less power-consuming.

Fourth Generation: Microprocessors

• 1971: Intel developed the first microprocessor.
• Entire computer functionality on a single chip.
• Modern computers use microprocessors.

Fifth Generation: VLSI

• 1980s, still current.
• Very large scale integration (millions/billions of transistors).
• Faster, more powerful computing.

Key Computers in History

Altair 8800

• First personal computer (PC), cost $395.
• Assembled from a kit; for enthusiasts.
• Used by notable figures like Bill Gates.

Apple II

• Released in 1977, had a monitor and keyboard.
• No assembly required, user-friendly for average consumers.
• Popular in education.

IBM PC

• Significant after Apple II, released by IBM.
• Dominated market, gained business trust.
• Named Time Magazine's Man of the Year in 1982.

Software and User Interaction

Command Line Interface

• Early method for interacting with computers.
• Required knowledge of commands; not user-friendly.

Graphical User Interface (GUI)

• Popularized by Apple, invented by Xerox in the 1970s.
• Introduced in Apple Lisa and Macintosh.

Notable Software

Early Software Programs

• WordStar: First word processor.
• VisiCalc: First electronic spreadsheet.
• PageMaker: First desktop publishing software.

Improvements

• WordPerfect: Enhanced word processing.
• Lotus 1-2-3: Popular spreadsheet software.
• Microsoft Word & Excel: Modern standards in word processing and spreadsheets.

The Internet Age

Web Browsers

• Mosaic: First web browser (1993).
• Netscape Navigator: Followed Mosaic in 1990.
• Microsoft Internet Explorer: Released in 1995.