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Peripheral Device An input, output, or auxiliary storage device attached to a computer. |
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Auxiliary Storage Device A device that stores data in encoded form outside the computer's main memory. |
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Hardware The physical components of a computer. |
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Software Computer programs; the set of all programs available on a computer. |
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In addition to the programs that we write or purchase, there are programs in the computer that are designed to simplify the user/computer interface, making it easier for us to use the machine. The interface between user and computer is a set of I/O devicesfor example, a keyboard and a screenthat allows the user to communicate with the computer. We work with the keyboard and the screen on our side of the interface boundary; wires attached to the keyboard and the screen carry the electronic pulses that the computer works with on its side of the interface boundary. At the boundary itself is a mechanism that translates information for the two sides. |
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Interface A connecting link at a shared boundary that allows independent systems to meet and act on or communicate with each other. |
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When we communicate directly with the computer through a keyboard and a screen, we are using an interactive system. Interactive systems allow direct entry of programs and data and provide immediate feedback to the user. In contrast, batch systems require that all data be entered before a program is run and provide feedback only after a program has been executed. In this text we focus on interactive systems, although in Chapter 4 we discuss file-oriented programs, which share certain similarities with batch systems. |
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The set of programs that simplifies the user/computer interface and improves the efficiency of processing is called system software. It includes the compiler as well as the operating system and the editor (see Figure 1-11). The operating system manages all of the computer's resources. It can input programs, call the compiler, execute object programs, and carry out any other system commands. The editor is an interactive program used to create and modify source programs or data. |
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