Computers

Computers A.

History:

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Developed in the late 1940’s and early 1950’s 1971: Dr. Ted Hoff (microprocessor) 1976: Steve Jobs and Steve Wozniak (apple computer)

B.

What is ○ ○ ○ ○

C.

Computer System ○ Software: applications

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a computer? Inputs data Processes data Stores data in memory or storage device Outputs information

Hardware: machine (wires and transistors) Information: output People: users of the computer Data: text, numbers, sounds, images, and video

D. Computer Operations: ○ Arithmetic: addition, subtraction, multiplication, division

○ E.

Logical: comparing 2 values & taking action based on the comparison

Categories of Computers: ○ Special Purpose: used to control devices

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General Purpose: based on size, function, cost, and performance

     F.

Desktop: components fit on/under a desk Mobile: notebook computers and tablet pc’s Mid-range servers: support hundreds of users Mainframes: thousands of users, used by large corporations Supercomputers: operations requiring mathematical equations

Computer Software: ○ Application: performs specific tasks for users (word processing)

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System: controls the computers OS (Windows, Linux)

G. Electronic Communications: ○ Allows computers to talk to each other and to other devices ○ 4 components:  Sender: computer sending a message  Receiver: computer receiving a message  Channel: media that carries a message  Protocol: rules that govern the processing of a message between computer H. Network Systems: ○ Consists of multiple users who share data and resources

○ ○ I.

Server: where data and software programs are stored (connected to the HUB) Local area network: network computers located in the same general area

Other types of networks: ○ Intranet: network built for employees that wouldn’t be accessible outside

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Extranet: intranet that allow certain users to access internal networks Internet: evolved from a government research project to help the military and scientists (world’s largest network)

J. K.

Functions of Computer: ○ ○ ○ ○ ○

Communications capability Accuracy Reliability Speed Storage