ComputerIINTRODUCTIONBabbage's Difference EngineConsidered by many to be a direct forerunner of the modern computer, the Difference Engine was able to compute mathematical tables. This woodcut shows a small portion of the ingenious machine, which was designed by Charles Babbage in the 1820s. Although the device did not have a memory, Babbages later idea for the Analytical Engine would have been a true, programmable computer if the technology of his time had been able to build it.THE BETTMANN ARCHIVEComputer,machinethatperforms tasks, such as calculations or electronic communication, under the control of a set of instructions called a program. Programs usually reside within the computer and are retrieved and processed by the computers electronics. The program results are stored or routed to output devices, such as video display monitors or printers. Computers perform a wide variety of activities reliably, accurately, and quickly.IIUSES OF COMPUTERSPeopleusecomputersin many ways. In business, computers track inventories with bar codes and scanners, check the credit status of customers, and transfer funds electronically. In homes, tiny computers embedded in the electronic circuitry of most appliances control the indoor temperature, operate home security systems, tell the time, and turn videocassette recorders (VCRs) on and off. Computers in automobiles regulate the flow of fuel, thereby increasing gas mileage, and are used in anti-theft systems.