IPO cycle of computer

Any electronic machine that performs 'IPO cycle' is known as computer.

IPO Cycle figure is given below :-
I P O
Input
(raw data)
input devices
> Mouse
> Keyboard
> Scanner
> Webcam
> Digital camera
> Microphone
> Joysticks, etc.

Process
(Invisible)
processing device
>CPU
(Central Processing Unit) > Printer

Output

(result)
output devices
> Monitor
> Speaker
> Printer

Input :- Input is the raw data entered into a computer from the input devices. It is the collection of numbers, letters, images, etc. Keyboard, Mouse, scanner, webcam, etc are some examples of the input devices.

Process :- Process is the operation of data or information as per given instruction. It is totally internal process of the computer system. CPU (Central processing Unit) is the main processing device of the computer.

Output :- Output is the result of processed data given by computer after data processing. we can save these results in the storage devices for the future use. Monitor, Printer, Speaker are the main output devices.

IPO Cycle in Detail

Input Devices

Devices which transfer data, programs, or signals into a computer systems are called input devices. These devices are used to give raw data to the computer to perform the specific tasks. Firstly, the data, programs, a signals are fed into the input devices in a suitable form, and are then converted by the device into electrical signals from human-readable format that are transmitted to the central processing unit of the computer.

The Processing Device
The Processor
(CPU – Central Processing Unit)

The main unit inside the computer is the CPU. This unit is responsible for all events inside the computer. It controls all internal and external devices, performs arithmetic and logic operations. The CPU (Central Processing Unit) is the device that interprets and executes instructions.
The operations, a microprocessor performs are called the instruction set of this processor. Processors differ from one to another by the instruction set. If the same program can run on two different computer brands they are set to be compatible. Programs written for IBM compatible computers will not run on apple computers because these two architectures are not compatible.
Mainframes and early mini computers contained circuit boards full of integrated circuits cards implemented the central processing unit. Today’s single chip central processing units, called microprocessors, make personal computers and workstations possible. The CPU has the ability to fetch, decode, and execute instructions and transfer information to and from other recourses over the computer’s main data-transfer path, the bus. By definition, the CPU is the chip that functions as the brain of a computer. In some instances, however, the term encompasses both the processor and the computer’s memory or, even more broadly, the main computer console.
All processors use transistors as switched to produce signals, much like a light switch, which digitizes the information and breaks them up into small chumps. If you have one transistor you can perform two signals-on and off. If you have two transistors you can perform signals-both on, both off, first on, second off, first off, second on. This is interpreted in binary, such as: 00111001 – 0 for off, 1 for on.
The CPU is composed of several units:
The Control Unit (CU) directs add controls the activities of the internal and external devices. It interprets the instructions obtained into the computer, determines what data are needed, where it is stored, where to stored the results of the operations, and sends the control signal to the devices involved in the execution of the instructions.

The Arithmetic and Logic Unit (ALU) is the part where actual computations take place. It consists of circuits, which perform arithmetic operations (e.g. Addition, subtraction, multiplication, division) over data receive from memory and capable to compare numbers.

While performing these operations the ALU takes data from the temporary storage area inside the CPU named registers. Registers are a group of cells used for memory addressing, data manipulations and processing. Some of the registers are general purpose and some are reserved for certain functions. It is a high speed memory, which holds only data for immediate processing and result of this processing. If these results are not needed for the next instruction, they are sent back to the main memory and registers are occupied by the new data used in the next instruction.
All activities in the computer systems are composed of thousands of individual steps. These steps should follow in some order in fixed interval of times. These intervals are generated by the clock units. Every operation within the CPU take place ate the clock pulse. No operations, regardless of how simple, can be performed in less time then transpires between ticks of this clock. But some operations require more than one clock pulse. The faster the clock runs, the faster the computer performs. The clock rate is measured in mega hertz (MHZ) or million ticks per second. In most modern micro processors the clock is usually incorporated within the CPU.
The two main features of the CPU are,

• It’s speed measured in millions of instructions per second.

• The word size.
  

The word size is the number of bits the CPU can process at a time. An 8-bit processor manipulates with 8-bits simultaneously. Consider a simplify example: the CPU needs to add up two 4-digit numbers. For an 8-bit CPU, it will take four operations, a separate operation for addition of each of the four digits. A 16-bit processor will be able to work on two digits simultaneously, so it will need only two operations. A 32-bit processor will complete addition in one operation.
As mention earlier the CPU controls all the other chips on the board. Now we need to have a look at how this is affected. Think of lifting your arm. How does our brain know when to move it and how far? The answer is: the brain passes the in formations down the nerves to the appropriate muscles and it all happens. By this comparison the computer has three nervous systems, all-working together. All around the motherboard or printed circuit board (PCB) there are groups of wires, or lines. These are known as busses.

Output Devices

Output devices are used to get final result from the computer. Firstly, output is displayed on monitor. Then we can print out these outputs on a paper with the help of printer. The purpose of the output devices is to translate data and informations from electrical impulses to human-readable format.
The output device, which is necessary for the computer to display messages to the user, is a monitor. If we want to keep the copy of the work on paper, we used printers. Plotters are devices that are more suitable for the large scale outputs like engineering drawings and high quality graphics.