In essence the PC is a type of microcomputer, originally created by IBM in 1981 and more recently produced in a variety of forms by dozens of manufacturers throughout the world. The original components of the PC have been upgraded several times during the last few years, so that while the early models may have had an 8088 processor, 128k RAM and one low capacity floppy disk, later models are more likely to have an 80286 processor, 640k RAM, a high density floppy disk and a 20 Mbyte hard disk (the normal PC/AT system). However, the apparent structure of these variants (although not necessarily the actual structure) has remained remarkably compatible over the years, and the PCs remain basic micros which can run a relatively standardised operating system and can communicate with external devices using a relatively standardised but versatile connection system.
KeywordsExternal Device Direct Memory Access System Board User Port Disk Operating System
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