Computer Components

CPU (Central Processing Unit):

CPU is the brain of a computer. It controls the entire system and executes instructions.

1)    It is the hub of processing activities.

2)    In large machines, CPUs require one or more printed circuit boards.

3)    In personal computer CPU is housed in a single chip called microprocessor. 

 Parts of CPU:

 It has mainly three parts.

 a) Control Unit (CU)

 b)   Arithmetic & Logic Unit (ALU)

 c) Memory Unit (MU)

 a) Control Unit(CU): Control Unit is the most important part of the CPU. It controls the overall data-traffic that takes place within a computer. It issues necessary commands to relevant units. It fetches instructions from RAM and stores them in the instruction register and then transfers them to ALU registers. It acts like a traffic policeman.

  b)Arithmetic & Logic Unit (ALU): ALU consists of a number of adder and logic gates. It performs all the arithmetic and logic operations that take place in a computer. Arithmetic operations are addition, subtraction, multiplication etc. Logic operations are comparison operations, AND, OR, NOT etc.

 c) Registers: ALU and CU need memory. This memory consists of small temporary memory locations. These temporary memory locations are called registers.

Memory:  

Memory is the storage device inside the computer where data/information/programs stores.

Type of memory:

There are two types of memory.

1)Primary/Main memory

 2)Secondary Memory

1)      Primary/Main memory:

             It is the type of memory in the form of chips located on motherboard so that data travel quickly between main memory and CPU.

          Types of Main Memory:

       These are generally two types of main memory:

a)      Read Only Memory (ROM):

Read-only memory or ROM is a form of data storage in computers and other electronic devices that can not be easily altered or reprogrammed. It is non-volatile memory and the contents are retained even after the power is switched off.

b)     Random Access Memory (RAM):

Random Access Memory (RAM) is a type of data storage used in computers that is generally located on the motherboard. This type of memory is volatile and all information that was stored in RAM is lost when the computer is turned off.

2)      Secondary Memory

It is the type of memory to store bulk of information and lies outside the CPU. Secondary memory refers to storage devices, such as hard drives and solid state drives. It may also refer to removable storage media, such as USB flash drives, CDs, and DVDs.

Ports:

A port is an interface. It provides a direct link with the computer. All the I/O devices are connected to the computer through ports.

 Types of Ports:

     a)      Serial Ports: A serial port provides a link through which only one bit can be transferred at a time. It is also called male connector and has 9 or 25 pins. It is reliable for transmission over a long distance.

     b)     Parallel Ports: A parallel port provides a link for transmitting fast flow of data. It can transfer more than one bits at a time. It can transfer 8 or 16 bits at a time. It is also called female connector and has 25 pins.