* Larges ones are called MAINFRAMES and they have been around the longest.
*Even larger and more powerful than the mainframes are the SUPER COMPUTER.
*MINICOMPUTERS or MINIS- these computers were smaller than the mainframes.
*Computer manufacturers produced even smaller designs called MICRO-COMPUTER or MICROS.
*Smaller than your fingernail the chip is called MICROPROCESSOR.
*A SMALL BUSINESS COMPUTER- is a multi-user mini or micro that is usually found in smaller firms, providing the computational support for the entire organization.
*A PERSONAL COMPUTER- is micro that is used by a single person, by a few people working in the same area.
*LAPTOP, NOYEBOOK and PALMTOP- these are progressively smaller PC’s that are battery powered portables.
*PEN COMPUTER- is a smaller PC which got its name from its ability to accept input that is written on its screen with special pen.
*COMPUTERSCHEMATIC- a diagram of the basic units that are found in all computers.
*HARDWARE- computer units.
*CENTRAL PROCESSING UNIT- controls all of the other units of the computer system and transforms the input into output.
*SECONDARY STORAGE- provides a place to keep programs and data when thye are not in use.
*SOFTWARE LIBRARY- this are the stored programs.
*DATABASE- this is where the data are stored.
*The results of the processing are recorded by the OUTPUT UNITS.
DIFFERENT FORMS OF PRIMARY
*RAM- stands for RANDOM ACCESS MEMORY and is the name given to the integrated circuits that serve as the portion of Primary Storage used to store software and data.
*ROM- stands for READ ONLY MEMORY, it is as special type of primary storage that permits reading but not writing.
*CACHE MEMORY- the movement of the program instruction and data between primary storage and processor.
*A NANOSECOND- its a one billionth of a second.
POINTING DEVICES
*MOUSE- a small, lightweight device, approximately the size of a deck cards that fits into the palm of the hand.
*TRACKBALL- similar to the mouse to accept that the ball is on top instead of the bottom.
*TOUCH SCREEN- capability that allows you to enter data or instructions by simply touching a location using your finger.
*LIGHT PEN- is used to point at the screen in a manner similar to pointing at a touch screen with your finger.
*REMOTE CONTROL- it is possible to communicate wiht the computer in much the same way that you control a TV by using a hand- held remote control unit.
SOURCE DATA AUTOMATION INPUT DEVICES
*The relatively show input speeds can create INPUT BOTTLE- NECK of data awaitng entry into the computer.
*The input devices that read data by shining a bright light on it and then capturing the reflecting image on a matrix of PHOTO ELECTRIC CELLS are called OPTICAL READING UNITS or SCANNERS.
OUTPUT DEVICES CALLED PRINTERS.
*LINE-PRINTERS- was the first computer printers because they printed so rapidly that they appeared to be printing a line at the time.
*CHARACTER PRINTERS- print oe character at a time.
*The most popular character printer is the DOT MATRIC PRINTER.
*PAGE PRINTERS- the fastest printers are called page printers because they appear to print a page at a time.
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