1. Technology in Action Technology in Focus: History of the PC
In this Technology in Focus feature, we look at the history of the computer. We discuss some developments that helped make the computer powerful and portable, as well as the people who contributed to its development. We start with the story of the personal computer and how it grew to be as integral to our lives as the automobile.

2. Intel 8080 and the Altair 8800 The first microcomputer Sold as a kit
Switches for input
Lights for output
Gates and Allen create a compiler for Basic
MITS receives 4,000 orders
A company called MITS created a kit computer based on the Intel 8080 chip called the Altair It appeared on the cover of Popular Electronics in 1975 and quickly there were hundreds of orders a month for the $395 box of parts. The computer had switches for input and lights for output and had a total of 256 bytes of memory. (Today’s computers have 256,000,000 bytes) Bill Gates and Paul Allen saw the article, left Harvard and flew to Albuquerque, NM, convincing MITS that they could write a compiler to run the Basic computer language on the Altair. Their success led to the formation of Microsoft.

3. Apple I and Apple II Apple I built by Steve Wozniak in 1976
Apple II developed by Steve Jobs in 1977
Uses Motorola processor
First fully contained microcomputer
Highly successful
In 1976, Steve Wozniak and Steve Jobs met at the Homebrew Computing Club in Palo Alto. Wozniak had built a computer based on a Motorola microprocessor that worked well. Jobs joined up with him and together they developed the Apple Computer Company and the sensational Apple II, the first fully contained microcomputer in a plastic box, looking like a piece of consumer electronics. The machine was an instant success, selling for $1300.

4. Early Competitors Commodore TRS-80 Osborne
Around the time Apple was experiencing success with its computers, a number of competitors entered the market.
Among Apple’s strongest competitors were the Commodore PET 2001 and Tandy RadioShack’s TRS-80.
Commodore introduced the PET in January It was featured on the cover of Popular Science in October 1977 as the “new $595 home computer.”
Tandy RadioShack’s home computer also garnered immediate popularity. Just one month after its release in 1977, the TRS-80 Model 1 sold approximately 10,000 units. Priced at $599.95, the easy-to-use machine included a monochrome display and 4 KB of memory.
The Osborne Company introduced the Osborne in April 1981 as the industry’s first portable computer. Although portable, the computer weighed 24.5 pounds, and its screen was just 5 inches wide. In addition to its hefty weight, it came with a hefty price tag of $1,795. Still, the Osborne included 64 KB of memory, two floppy disk drives, and software programs installed (such as word processing and spreadsheet software). The Osborne was an overnight success, with sales quickly reaching 10,000 units per month.

5. IBM PC IBM enters small computer market 1981 Uses open architecture
Purchases operating system from Microsoft
As the microcomputer market grew, everyone waited to see if the dominant computer company, IBM, would enter the market. They did in 1981, but veered from their normal corporate philosophy by developing a product from off-the-shelf parts. There was only one essential part of the IBM PC that was proprietary, the ROM-BIOS.
Two choices they made changed the world of computing forever. One was choosing the Intel microprocessor, the other was choosing their operating system from Microsoft.
The IBM PC made it OK for American business to buy small computers and the sensational sales led software developers to write for it. The IBM PC became the standard by which all Intel/Microsoft PCs would be based. Unfortunately for IBM, their machine was cloned by Compaq in IBM had created an empire for Intel and Microsoft.

6. Beginners All-Purpose Symbolic Instruction Code (BASIC)
Revolutionized the software industry
Programming language that beginners could easily learn
Key language of the PC
Bill Gates and Paul Allen used BASIC to write the program for the Altair
Led to the creation of Microsoft
The software industry began in the 1950s with the development of programming languages such as FORTRAN, ALGOL, and COBOL. These languages were used mainly by businesses to create financial, statistical, and engineering programs for corporate enterprises.
The 1964 introduction of Beginners All-Purpose Symbolic Instruction Code (BASIC) revolutionized the software industry.
BASIC was a programming language that the beginning programming student could easily learn. It thus became enormously popular—and the key language of the PC.
In fact, Bill Gates and Paul Allen used BASIC to write the program for the Altair.
This program led to the creation of Microsoft, a company that produced software for the micro computer.

7. Advent of Operating Systems
Steve Wozniak invents floppy drive
Disk Operating System (DOS): Operating system that controlled the first Apples
Control Program for Microcomputers (CP/M): First operating system for Intel-based PCs
MS-DOS
Operating system for IBM PCs
Based on an operating system called Quick and Dirty Operating System (QDOS)
Created by Bill Gates and Paul Allen
All PCs using the Intel chip used MS-DOS
Because data on the earliest PCs was stored on audiocassettes (not floppies), many programs were not saved or reused. In 1978 Steve Wozniak developed a floppy disk drive called the Disk II. With the introduction of the floppy drive, programs could be saved with more efficiency, and operating systems developed.
Disk Operating System (DOS), developed by Wozniak and introduced in December 1977, was the OS that controlled the first Apple computers.
The Control Program for Microcomputers (CP/M), developed by Gary Kildall, was the first OS designed for the Intel 8080 chip (the processor for PCs).
In 1980, IBM approached Bill Gates at Microsoft to write an OS program for the IBM PC. Microsoft developed MS-DOS.
MS-DOS was based on an OS called Quick and Dirty Operating System (QDOS). Microsoft bought the nonexclusive rights to QDOS and distributed it to IBM.
Eventually, virtually all personal computers running on the Intel chip used MS-DOS as their OS. Microsoft’s reign as one of the dominant players in the PC landscape had begun.

8. Software Application Explosion
Electronic Spreadsheets
VisiCalc
Lotus and Microsoft Excel
Word Processing
WordStar
Word for MS-DOS
Word Perfect
Bricklin and Frankston
Inclusion of floppy disk drives in personal computers not only facilitated the storage of operating systems, but also set off a software application explosion.
In 1978, Dan Bricklin recognized the potential for a spreadsheet program that could be used on PCs. He and his friend Bob Frankston thus created the program VisiCalc. VisiCalc became an instant success, with more than 100,000 copies sold in its first year.
After VisiCalc, other electronic spreadsheet programs entered the market: Lotus in 1982 and Microsoft Excel in 1985.
Meanwhile, word processing software was gaining a foothold. WordStar, the first word processing application, came out in disk form in Competitors such as Word for MS-DOS (the precursor to Microsoft Word) and WordPerfect soon entered the market.
VisiCalc screenshot

9. Graphical User Interface
Xerox
Palo Alto Research Center
Alto: 1972
Apple
Lisa: 1983
Macintosh: 1984
Xerox Alto
Another important advancement in PCs was the introduction of the graphical user interface (GUI), which allowed users to interact with the computer more easily.
In 1972, Xerox was hard at work in its Palo Alto Research Center designing a PC of its own. Named the Alto, it included a mouse and a file management system with directories and folders. For a variety of reasons, Xerox never sold the Alto commercially.
In 1983, Apple introduced the Lisa, the first successful PC brought to market to use a GUI. It incorporated a user interface similar to the Alto, including features such as windows, drop-down menus, icons, a file system with folders and files, and a mouse.
In 1984, Apple introduced the Macintosh, which was everything the Lisa was and then some, and at about a third of the cost. The Macintosh was also the first personal computer to introduce 3.5-inch floppy disks with a hard cover.

10. The Internet Boom Mosaic Netscape Internet Explorer Windows 95
The GUI made it easier for users to work on the computer. The Internet provided another reason for consumers to buy computers. Now they could conduct research and communicate with each other in a new and convenient way.
In 1993, the Web browser Mosaic was introduced. This browser allowed users to view multimedia on the Web, causing Internet traffic to increase by nearly 350 percent.
in 1994, the Mosaic development team developed the commercial Web browser Netscape. Netscape’s popularity grew quickly, and it soon became a predominant player in browser software.
Meanwhile, companies discovered the Internet as a means to do business, and computer sales took off. IBM-compatible PCs became the PC system of choice when, in 1995, Microsoft introduced Internet Explorer, a Web browser that integrated Web functionality into Microsoft Office applications, and Windows 95, the first Microsoft OS designed to be principally a GUI OS.

11. Early Computer History
Pascalene 1624
The first accurate mechanical calculator
Created by Blaise Pascal
Used to add, subtract, multiply, and divide
Jacquard Loom 1820
Created by Joseph Jacquard
A machine that automated the weaving of complex patterns
Used holes punched in cards to automate the process
The Pascalene was the first accurate mechanical calculator. This machine, created by the French mathematician Blaise Pascal in 1642, used revolutions of gears to count by tens. The Pascalene could be used to add, subtract, multiply, and divide. The basic design of the Pascalene was so sound that it lived on in mechanical calculators for more than 300 years.
Nearly 200 years later, Joseph Jacquard revolutionized the fabric industry by creating a machine that automated the weaving of complex patterns. Although not a counting or calculating machine, the Jacquard Loom was significant because it relied on stiff cards with punched holes to automate the process. Much later this process would be adopted as a means to record and read data by using punch cards in computers.

12. Early Computer History
Analytical Engine 1834
Created by Charles Babbage
The father of computing
The first automatic calculator
Includes components similar to those found in today's computers
Hollerith Tabulating Machine 1890
Created by Herman Hollerith
Used punch cards to tabulate census data
Hollerith started the Tabulating Machine Company, which later became IBM
Decades later, in 1834, Charles Babbage designed the first automatic calculator, called the Analytical Engine. Although it was never developed, Babbage’s detailed drawings and descriptions of the machine include components similar to those found in today’s computers, including the store (RAM), the mill (central processing unit), as well as input and output devices. This invention gave Charles Babbage the title of the “father of computing.”
In 1890, Herman Hollerith developed a machine called the Hollerith Tabulating Machine that used punch cards to tabulate census data. Hollerith left the Census Bureau in 1896 to start the Tabulating Machine Company, which later changed its name to International Business Machines, or IBM.

13. Early Computer History
Z1 1936
Created by Konrad Zuse
The Z1 is a mechanical calculator
It included a control unit and memory functions
Atanasoff-Berry Computer 1939
Created by John Atanasoff and Clifford Berry
The first electrically powered digital computer
Used vacuum tubes to store data
The first computer to use the binary system
German inventor Konrad Zuse is credited with a creating a mechanical calculator called the Z1 in The Z1 is thought to be the first computer to include features that are integral to today’s systems, including a control unit and separate memory functions.
In 1939, John Atanasoff and, Clifford Berry built the first electrically powered digital computer, called the Atanasoff-Berry Computer. The computer was the first to use vacuum tubes to store data. Most important, the ABC was the first to use the binary system.
Atansoff-Berry Computer

14. Early Computer History
Harvard Mark I 1944
Created by Howard Aiken and Grace Hopper
A computer used by the US Navy for ballistics calculations
Hopper’s contribution to computing was
Invention of the compiler
Coined the term “computer bug”
Turing Machine 1939
Created by Alan Turing
A hypothetical model that defined a mechanical procedure or algorithm
Concept of an infinite tape that could read, write, and erase was precursor to today’s RAM
From the late 1930s to the early 1950s, Howard Aiken and Grace Hopper designed the Mark series of computers at Harvard University. The U.S. Navy used these computers for ballistic and gunnery calculations. Aiken, an electrical engineer and physicist, designed the computer, while Hopper did the programming.
The Harvard Mark I, finished in 1944, could perform all four arithmetic operations (addition, subtraction, multiplication, and division).
Hopper’s greatest contribution was the invention of the compiler, a program that translates English language instructions into computer language. Hopper was also the first to “debug” a computer when she removed a moth that had flown into the Harvard Mark I. After that, problems that caused the computer to not run were called “”bugs.”
In 1936, British mathematician Alan Turing created an abstract computer model that could perform logical operations. The Turing Machine was not a real machine but rather a hypothetical model that mathematically defined a mechanical procedure (or algorithm).
Turing’s concept described a process by which the machine could read, write, or erase symbols written on squares of an infinite paper tape. This concept of an infinite tape that could be read, written to, and erased was the precursor to today’s RAM.
1st use of “computer bug”

15. Early Computer History
ENIAC 1944
Created by John W. Mauchly and J. Presper Eckert
The first successful high-speed electronic digital computer
UNIVAC 1951
The first commercially successful electronic digital computer
Used magnetic tape
ENIAC
The Electronic Numerical Integrator and Computer (ENIAC) was created by John W. Mauchly and J. Presper Eckert and was placed in operation in The ENIAC is generally thought of as the first successful high-speed electronic digital computer.
The Universal Automatic Computer, or UNIVAC, was the first commercially successful electronic digital computer. Completed in 1951, the UNIVAC operated on magnetic tape (as opposed to its competitors, which ran on punch cards).
UNIVAC

16. Early Computer History
Transistors 1945
Invented at Bell Laboratories
Replaces vacuum tubes
Integrated circuits 1958
Invented by Jack Kilby of Texas Instruments
A small chip containing thousands of transistors
Enabled computers to become smaller and lighter
In 1945, scientists at the Bell Telephone Laboratories invented the transistor as a means to store data. The transistor replaced the bulky vacuum tubes of earlier computers and was smaller and more powerful.
In 1958, Jack Kilby, while working at Texas Instruments, invented the world’s first integrated circuit, a small chip capable of containing thousands of transistors. This consolidation in design enabled computers to become smaller and lighter.

17. Early Computer History
Microprocessor chip 1971
Created by Intel Corporation
A small chip containing millions of transistors
It functions as the central processing unit (CPU)
In 1971, the Intel Corporation introduced the microprocessor chip, a small chip containing millions of transistors. The microprocessor functions as the CPU.

18. Computer Generations First-generation computers (1946–1958)
UNIVAC
Use vacuum tubes to store data
Second-generation computers (1959–1964)
Use transistors to store data
Third-generation computers (1965–1970)
Use integrated circuits
Fourth-generation computers (1971–Today)
Use a microprocessor chip
Computers have been classified in four generations. The first generation, like the ENIAC and UNIVAC, used vacuum tubes for memory. The second generation used transistors. Integrated circuits were the hallmark of third-generation computers. Fourth-generation computers use the microchip.