A computer is a machine that processes information according to instructions given by humans. The microcomputer is commonly referred to as the PC, or personal computer. It is smaller than a mainframe or mini-computer, and typically is placed on a deskt op. The microcomputer system consists of hardware, software, the CPU, disk drives, and peripheral equipment.
Hardware is any part of the computer that can be physically touched. Some example of hardware are: the monitor, keyboard, printer, mouse, and disk drive. (illustration )
Software is the intangible part of the system. Software is a set of instructions programmed into the computer or loaded in from a disk. In common parlance, software now refers to the programs available on disks, such as Oregon Trail or Kid Pix. (illustration)
CPU stands for Central Processing Unit. It is the part of the computer which receives, processes, and stores or sends on data. The CPU contains the control unit and the arithmetic logic unit.
RAM stands for Random Access Memory. It is a memory chip in the computer which accepts the program loaded in from a disk, and also has space for the user to work in. For this reason, it is often referred to as the "d esktop" memory. Anything on the desktop can be accessed by the user. However, this memory is temporary, and RAM is wiped clean when the computer is turned off. For this reason, it is important to save work regularly. Horror stories abound in which hours o f work have been lost when a system shut down inadvertently. So the rule is: Save Early and Often! (illustration )
ROM stands for Read Only Memory. It is a memory chip in the computer which the manufacturer has programmed and cannot be accessed or changed by the user. (illustration )
Input devices are those parts we use to put information into the computer's RAM. Some examples of input devices are: the keyboard, mouse, joystick and touch screen. (illustration )
Output devices are those parts that put information out to the user. Some examples of output devices are: the monitor and the printer. ( illustration)
Some parts of the system are flexible enough to act as both input and output. The disk drive is one of these. When a program is loaded onto RAM from a disk drive, the drive is working as an input device. When the user saves work to a disk, the disk dri ve is acting as an output device. Some other output devices would be a tape or a modem.