• Peripheral devices are connected to computer but is not part main of computer architecture.
• It don’t involve in memory and processing.
• Peripheral devices include input, output and storage.

Different types of I/O port are:

1. USB Port
2. Serial Port
3. Parallel Port
4. HDMI
5. VGA

• USB stand for universal Serial Bus.
• Used for short distance digital data communication.
• Also supply electric power across the cable to device.
• Available both in wired and wireless version.
• Data travels at 12 megabits per second.

• Used for external modems and older computer mouse.
• Two versions – 9 pin, 25 pin.
• Data travels at 115 kilobits per second.
• Provides the physical connection between the equipment.
• Able to transmit a single stream of data at a time.

• It transmit or receive data down multiple bundled cables to a peripheral device.
• Faster in comparison to the serial communication.
• Used to achieve parallel transmission.
• Capable of delivering multiple streams of data.
• Used for scanner and printer.
• 25 pin model.

• Stand for High-Definition multimedia Interface.
• Combines the transmission of both digital audio and digital video into a single interface.
• Used with DVD players, digital television players, set-top boxes and other audio-visual devices.
• It offers loss less transmission and better quality video.
• Texts are displayed with more sharpness on the screen.
• Deliver deep color depth due to support of various bit formats eg. 10/12/16 bits.

• Stand for video graphic Array.
• It is a standard connector used for computer video output.
• Requires seperate audio cable.
• Uses analog signal instead of digital signal.
• It is not as good as HDMI for video gaming purpose.
• Provides lower resolution than HDMI.
• It was developed by IBM, 1987.

• I/O interfaces provides a method for transferring information between internal memory and CPU register with external I/O devices.
• They are special hardware components between CPU and peripheral to supervise and synchronize all input and output devices.

They Restore Following Problems

1. Problems between electromechanical and electronic devices.
2. Problem between CPU and storage devices because CPU is very fast than storage devices etc.

1. Decode device address.
2. Decode command.
3. Synchronize Data Flow.

• The input/output processor or I/O processor is a processor separate from the CPU design to handel only input/output task.
• The I/O processor can perform actions without interruption from CPU.
• CPU only need to initiate the I/O processor by telling it what activity to perform.
• In the absence of input/output processor all the work is perform by CPU.
• In advance input/output processor may be there is a memory.

I/O interface communicate with external devices connected to computer. They help in data transfer and exchange between processor and other-components.

3 main types of I/O technique.