IGNOU BCA 1st sem Solved Assignment - What is the role of Central Processing Unit in a Computer? Find the details of CPU of present computers. What are the different types of Computers? Give one example of each type.

What is the role of Central Processing Unit in a Computer? Find the details of CPU of present computers. What are the different types of Computers? Give one example of each type.

Ans

role of Central Processing Unit in a Computer

The CPU is the 'brain' of the computer. It is where all the searching, sorting, calculating and decision making takes place. The CPU contains a tiny quartz clock. Each time this clock 'ticks', one instruction can be dealt with by the CPU. So the more times this clock ticks per second, the more instructions the CPU can carry out and the faster things get done.

The speed of the CPU is measured in either Megaherts (MHz) or more commonly now in Gigahertz (GHz). A 1 MHz CPU can carry out one million instructions per second. A 1 GHz CPU can carry out 1 billion instructions per second!

A typical CPU installed in a computer today would run at around 3 GHz.

Depending on their processing powers, size and area of use, they have been classified into various types. Based on the operational principle, computers can be classified as analog and digital. Based on their processing powers, they can be categorized as mainframe and microcomputers. Based on the usage, they can be grouped under desktop computers, laptops, tablets, netbooks, personal digital assistants (PDAs) and even tiny wearable ones. Here's more on the different types of computers.

Analog Computers: These are almost extinct today. These are different from a digital computer because an analog computer can perform several mathematical operations simultaneously. It uses continuous variables for mathematical operations and utilizes mechanical or electrical energy.

Digital Computers: They use digital circuits and are designed to operate on two states, namely bits 0 and 1. They are analogous to states ON and OFF. Data on these computers is represented as a series of 0s and 1s. Digital computers are suitable for complex computation and have higher processing speeds. They are programmable. Digital computers are either general purpose computers or special purpose ones. General purpose computers, as their name suggests, are designed for specific types of data processing while general purpose computers are meant for general use.
Hybrid Computers: These computers are a combination of both digital and analog computers. In this type of computers, the digital segments perform process control by conversion of analog signals to digital ones.

Mainframe Computers: Large organizations use mainframes for highly critical applications such as bulk data processing and ERP. Most of the mainframe computers have capacities to host multiple operating systems and operate as a number of virtual machines. They can substitute for several small servers.

✦ Microcomputers: A computer with a microprocessor and its central processing unit is known as a microcomputer. They do not occupy space as much as mainframes do. When supplemented with a keyboard and a mouse, microcomputers can be called personal computers. A monitor, a keyboard and other similar input-output devices, computer memory in the form of RAM and a power supply unit come packaged in a microcomputer. These computers can fit on desks or tables and prove to be the best choice for single-user tasks.

 Desktop Computers: A desktop computer is intended to be used on a single location. The spare parts of a desktop computer are readily available at relatively lower costs. Power consumption is not as critical as that in laptops. Desktop computers are widely popular for daily use in the workplace and households.

✦ Laptops: Similar in operation to desktop computers, laptop computers are miniaturized and optimized for mobile use. Laptops run on a single battery or an external adapter that charges the computer batteries. They are enabled with an inbuilt keyboard, touch pad acting as a mouse and a liquid crystal display. Their portability and capacity to operate on battery power have proven to be of great help to mobile users.

✦ Netbooks: They fall in the category of laptops, but are inexpensive and relatively smaller in size. They had a smaller feature set and lesser capacities in comparison to regular laptops, at the time they came into the market. But with passing time, netbooks too began featuring almost everything that notebooks had. By the end of 2008, netbooks had begun to overtake notebooks in terms of market share and sales.

✦ Personal Digital Assistants (PDAs): It is a handheld computer and popularly known as a palmtop. It has a touch screen and a memory card for storage of data. PDAs can also be used as portable audio players, web browsers and smartphones. Most of them can access the Internet by means of Bluetooth or Wi-Fi communication.

✦ Minicomputers: In terms of size and processing capacity, minicomputers lie in between mainframes and microcomputers. Minicomputers are also called mid-range systems or workstations. The term began to be popularly used in the 1960s to refer to relatively smaller third generation computers. They took up the space that would be needed for a refrigerator or two and used transistor and core memory technologies. The 12-bit PDP-8 minicomputer of the Digital Equipment Corporation was the first successful minicomputer.

✦ Servers: They are computers designed to provide services to client machines in a computer network. They have larger storage capacities and powerful processors. Running on them are programs that serve client requests and allocate resources like memory and time to client machines. Usually they are very large in size, as they have large processors and many hard drives. They are designed to be fail-safe and resistant to crash.

✦ Supercomputers: The highly calculation-intensive tasks can be effectively performed by means of supercomputers. Quantum physics, mechanics, weather forecasting, molecular theory are best studied by means of supercomputers. Their ability of parallel processing and their well-designed memory hierarchy give the supercomputers, large transaction processing powers.

✦ Wearable Computers: A record-setting step in the evolution of computers was the creation of wearable computers. These computers can be worn on the body and are often used in the study of behavior modeling and human health. Military and health professionals have incorporated wearable computers into their daily routine, as a part of such studies. When the users' hands and sensory organs are engaged in other activities, wearable computers are of great help in tracking human actions. Wearable computers do not have to be turned on and off and remain in operation without user intervention.

✦ Tablets: Tablets are mobile computers that are very handy to use. They use the touch screen technology. Tablets come with an onscreen keyboard or use a stylus or a digital pen. Apple's iPad redefined the class of tablets.