Chapter 2: Classification Of Digital Computers
© Er. Rajan Karmacharya -2008
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Computer Systems are classified as Microcomputers, Minicomputers, Mainframes and Supercomputers.
1. Micro Computer
• Are the smallest computer systems on the basis of size
• Are called micro computer because microprocessor is used as its CPU which are very small
• Are also called PC(Personal Computers) or home computers
• Smallest are laptop, notebook and palmtop computers.
• Examples: IBM Pentium PC, Apple/Macintosh etc
Characteristics:
• Smallest in term of size
• Speed and cost is also less as compared with other super, mainframe and mini computers.
• Since a single user system is used, storage devices and memory are smaller size.
Microcomputers are of two types: Personal Computers and Workstations
1.1 Personal Computers (PCs)
It can be defined as a small, relatively inexpensive computer designed for an individual user.
In price, personal computers range anywhere from a few hundred pounds to over five
thousand pounds. All are based on the microprocessor technology that enables
manufacturers to put an entire CPU on one chip. PCs are used for word processing,
accounting, desktop publishing, and for running spreadsheet and database management
applications. At home, the most popular use for personal computers is for playing games
and recently for surfing the Internet.
Personal computers first appeared in the late 1970s. One of the first and most popular
personal computers was the Apple II, introduced in 1977 by Apple Computer. During the
late 1970s and early 1980s, new models and competing operating systems seemed to appear
daily.
1.2 Workstation
It is a type of computer used for engineering applications, desktop publishing, software
development, and other types of applications that require a moderate amount of computing
power and relatively high quality graphics capabilities. Workstations generally come with a
large, high-resolution graphics screen, at large