What are small size modern computers?


Great development that took place in the field of semiconductor technology resulted in the reduction of size of modern computers. With the development of transistors the size of computer came down from room size to shelf size. Later on with the development of IC technology computer size shrinked to box size. With further development of single chip CPU with VLSI technology, further reduction in size of computers became possible. Now with the latest ultra large scale integrated circuits, entire CPU, memory and I/O ports and other semiconductor devices like timers, ADC, DAC etc. Can be integrated into single chip resulting in design of palm top computers.

What is Multitasking OS?


A multitasking OS allow a user to perform more than one computer task such as the operation of an application program at atime. The operating system is able to keep track of where the control is in these tasks and go from one to another without loosing information. When some one open a web browser and then open say word, at the same time, he is causing the OS to do multitasking. A time shared OS allow multiple users to use the same system at the same time. This is the main advantage of multi user operating system. Thus resources can be shared also.

What is Time Sharing OS?


In this type of OS , multiple users can use the same computer. User programs are loaded into computer memory and CPU is switched rapidly between user programs, giving each user the impression that computer is attending to His/her programs.

What is Compact Disk?


It is made from a 1.2 mm thick disk of pure poly carbonate plastic. Data is recorded in its surface on one side in the form of pits and lands which represents zeros and ones. A 12cm standard CD can store 650-703 MB of data.

What is Magnetic Tape?

It is sequential storage medium. It include a thin magnetizable coating on a long and narrow strip involving plastic. A tape drive uses correctly controlled motors to wind the tape derived from one of reel to another passing a tape head as it does the winding. Magnetic tapes that could store upto 1 TB can be found. They are generally used for back purpose. Their speed is fewer and cannot have random access of data.

What is Hard Disk?

A Hard Disk uses round flat disks called platters coated on both sides which has a special media material designed to store information available as magnetic patterns. The platters are mounted by cutting a hole from the center and stacking them onto a spindle. The platters rotate at high speed driven by a special spindle motor connected towards spindle. Data is recorded on either surface of a platter. The very best most and bottom most platters have only their inner sides recorded with data. Typical hard disk can keep upto 160 GB of files.

What is Floppy Disk?

A Floppy disk is a data storage medium that consists of a disk of thin, flexible magnetic storage medium encased within a square or rectangular plastic layer. The standard 3/1 inch high density floppy can be used to store 1. 44 mb of data. There are many high capacity floppy disk that may store upto 200 mb of data. Floppy disks are becoming more and more unpopular because of unreliability of the device.