Pricipios de contabilidad

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Appendix A
History of Microcomputers
1965
Honeywell corporation introduces the H316 “Kitchen Computer.” This is the first home computer and is offered in the Neiman Marcus catalog for $10,600.

1970
Ken Thompson and Denis Ritchie create the UNIX operating system at Bell Labs. UNIX will become the dominant operating system for criticalapplications on servers, workstations, and high-end microcomputers.

1971
In 1971, Dr. Ted Hoff puts together all the elements of a computer processor on a single silicon chip slightly larger than one square inch. The result of his efforts is the Intel 4004, the world’s first commercially available microprocessor. The chip is a four-bit computer containing 2,300 transistors (invented in 1948)that can perform 60,000 instructions per second. Designed for use in a calculator, it sells for $200. Intel sells more than 100,000 calculators based on the 4004 chip. Almost overnight, the chip finds thousands of applications, paving the way for today’s computer-oriented world, and for the mass production of computer chips now containing millions of transistors. Steve Wozniak and Bill Fernandezcreate a computer from chips rejected by local semiconductor companies. The computer is called the Cream Soda Computer because its creators drank Cragmont cream soda during its construction.

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1972
Dennis Ritchie and Brian Kernighan create the C programming language at Bell Labs. The UNIX operating system is re-written in C.C becomes one of the most popular programming languages for software development. 5.25-inch floppy diskettes are introduced, providing a portable way to store and move data from machine to machine.

1973
IBM introduces new mass storage devices: the eight-inch, two-sided floppy disk that can hold 400 KB of data and the Winchester eight-inch, four-platter hard drive that can hold an amazing 70MB of data. Bob Metcalfe, working at Xerox PARC, creates a methodology to connect computers called Ethernet.

1974
Intel announces the 8080 chip. This is a 2-MHz, eight-bit microprocessor that can access 64 KB of memory using a two-byte addressing structure. It has over 6000 transistors on one chip. It can perform 640,000 instructions per second. Motorola introduces the 6800 microprocessor. Itis also an eight-bit processor and is used primarily in industrial and automotive devices. It will become the chip of choice for Apple computers sparking a longrunning battle between fans of Intel and Motorola chips.

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1975
The first commercially available microcomputer, the Altair 880, is the first machine to be called a“personal computer.” It has 64 KB of memory and an open 100-line bus structure. It sells for $397 in kit form or $439 assembled. The name “Altair” was suggested by the 12-year-old daughter of the publisher of Popular Electronics because Altair was the destination that evening for the Enterprise, the Star Trek space ship. Two young college students, Paul Allen and Bill Gates, unveil the BASIClanguage interpreter for the Altair computer. During summer vacation, the pair formed a company called Microsoft, which eventually grows into one of the largest software companies in the world.

1976
Steve Wozniak and Steve Jobs build the Apple I computer. It is less powerful than the Altair, but also less expensive and less complicated. Users must connect their own keyboard and video display, andhave the option of mounting the computer’s motherboard in any container they choose — whether a metal case, a wooden box, or a briefcase. Jobs and Wozniak form the Apple Computer Company together on April Fool’s Day, naming the company after their favorite snack food.

1977
The Apple II computer is unveiled. It comes already assembled in a case, with a built-in keyboard. Users must plug in...