Classes of Computer Systems

Classes of Computer Systems

• Computer systems can be classified into various categories based on their size, processing power and application. The major classes of computer systems are described below.

1. Microcomputers (Personal Computers)

■ Microcomputers are small, low‒cost computers designed for individual users. They wing contain a single microprocessor as the Central Processing Unit (CPU). They are widely used in homes, schools and offices for applications such as word processing, internet bat browsing, entertainment and education.

■ Examples: Desktop computers, laptops, tablets and smartphones.

■ Characteristics :

 ♦ Single‒user system

 ♦ Compact and affordable

 ♦ Easy to operate and maintain

2. Minicomputers (Midrange Computers)

■ Minicomputers are medium‒sized systems that can support multiple users at the same time. They provide greater storage and processing capabilities than microcomputers. These computers are commonly used in small organizations, laboratories and industries to perform business or scientific tasks.

■ Examples:

DEC PDP‒11, VAX systems.

■ Characteristics :

 ♦ Multi‒user capability (10 to 100 users)

 ♦ Moderate processing speed

 ♦ Used for data management and control applications

3. Mainframe Computers

■ Mainframe computers are large and powerful systems capable of handling and processing very large amounts of data. They are designed to support hundreds or even thousands of users simultaneously. Mainframes are widely used in large organizations such as banks, insurance companies and airlines for critical applications like transaction processing and large database management.

■ Examples:

IBM zSeries, UNIVAC.

■ Characteristics :

 ♦ High reliability, speed and security

 ♦ Supports multiple terminals and users

 ♦ Operates continuously for long periods

4. Supercomputers

■ Supercomputers are the fastest and most powerful category of computers. They are used for highly complex scientific, engineering and research applications that require enormous computational power. They can perform trillions of calculations per second and are often used in weather forecasting, nuclear research, space exploration and artificial intelligence.

■ Examples:

PARAM (India), IBM Summit, Fugaku (Japan).

■ Characteristics :

 ♦ Extremely high processing speed.

 ♦ Very high cost and power consumption.

 ♦ Requires advanced cooling systems and a large physical space.

5. Workstations

■ A workstation is a high‒performance single‒user computer designed for technical or scientific applications. It offers higher processing power, better graphics capabilities and greater memory than a personal computer. Workstations are typically used by engineers, designers and software developers.

■ Examples: Sun Microsystems Workstations, HP Z‒series.

■ Characteristics:

 ♦ High‒speed processor and large memory.

 ♦ Suitable for CAD/CAM, 3D modelling and simulation.

 ♦ Supports advanced graphics and multitasking.

6. Server Computers

■ Server computers are systems that provide resources, data or services to other computers (clients) over a network. Servers are designed for reliability and are used in organizations to manage web hosting, databases, emails and file storage.

■ Examples:

Web servers, File servers, Database servers.

■ Characteristics :

 ♦ Multi‒user access and centralized control.

 ♦ High storage capacity and connectivity.

 ♦ Always operational for continuous service.

7. Embedded Systems

■ Embedded systems are special‒purpose computer systems built into other devices to perform dedicated tasks. They consist of microcontrollers or microprocessors embedded bus within the device and are designed for real‒time operation.

■ Examples: Washing machines, ATMs, Automobiles, Routers.

■ Characteristics :

 ♦ Compact and task‒specific.

 ♦ Low power consumption.

 ♦ High reliability and efficiency.

Table 1.2.1 compares various classes of computer systems.

Review Questions

1. Define microcomputer. Give two examples and mention their main characteristics.

2. Differentiate between mainframe computers and supercomputers based on their functions and applications.

3. Explain the features and uses of minicomputers.

4. What are embedded systems? Give two examples from daily life.

5. Write a short note on workstations and servers. How are they different from personal computers?