Introduction Of Computer System

Characteristicsof Computer
To understand why computers are such an important part of our lives, let us look at some of
its characteristics:

 Speed: Typically, a computer can carry out 3-4 million instructions per second.

 Accuracy: Computers exhibit a very high degree of accuracy. Errors that may occur
are usually due to inaccurate data, wrong instructions or bug in chips – all human
errors.

 Reliability: Computers can carry out same type of work repeatedly without throwing
up errors due to tiredness or boredom, which are very common among humans.

 Versatility: Computers can carry out a wide range of work from data entry and ticket
booking to complex mathematical calculations and continuous astronomical
observations. If you can input the necessary data with correct instructions, computer
will do the processing.

 Storage Capacity: Computers can store a very large amount of data at a fraction of
cost of traditional storage of files. Also, data is safe from normal wear and tear
associated with paper.

Advantages of using computer

Now that we know the characteristics of computers, we can see the advantages that
computers offer:

 Computers can do the same task repetitively with same accuracy.

 Computers do not get tired or bored.

 Computers can take up routine tasks while releasing human resource for more
intelligent functions.

Disadvantages of using computer

Despite so many advantages, computers have some disadvantages of their own:

 Computers have no intelligence; they follow the instructions blindly without considering the outcome.

 Regular electric supply is necessary to make computers work, which could prove
difficult everywhere especially in developing nations.

Booting
Starting a computer or a computer-embedded device is called booting. Booting takes place
in two steps:

 Switching on power supply

 Loading operating system into computer’s main memory

 Keeping all applications in a state of readiness in case needed by the user
The first program or set of instructions that run when the computer is switched on is called
BIOS or Basic
 Input Output System. BIOS is a firmware, i.e. a piece of software
permanently programmed into the hardware.
If a system is already running but needs to be restarted, it is called rebooting. Rebooting
may be required if a software or hardware has been installed or system is unusually slow.
There are two types of booting:

 Cold Booting: When the system is started by switching on the power supply it is
called cold booting. The next step in cold booting is loading of BIOS.

 Warm Booting: When the system is already running and needs to be restarted or
rebooted, it is called warm booting. Warm booting is faster than cold booting because
BIOS is not reloaded.