Page 78 - DCAP210_INTRODUCTION__TO_MICROPROCESSORS

Introduction to Microprocessors

Notes • Video controller pcb

• Data storage devices: Hard disk drive units, floppy disk drive units, and/or tape cassette
units

• I/O connector: Parallel or serial communications—A small fan: No special cooling
requirements; the unit relies on ambient temperature of the room or space
• Power supply

• No special requirements—Display monitors are output

In some cases the CPU and memory are located on the same pcb.

5.5 I/O Devices of Microcomputer System

The computer will be of no use if it is not communicating with the external world.
Thus, a computer must have a system to receive information from the outside world and must be
able to communicate results to the external world. For this purpose computers use input/output
devices. Input and output devices can also be written as I/O devices.
Input and output devices of a computer system are the devices that connect you to computer.
Input devices let you to transfer data and user command into the computer. Input devices
technologies are rapidly developing and are used to interact with the computer system. For
example, you can type in data by using a keyboard, or you can input data in picture form by
using a scanner in computer system. Inputs are data or signals received by the computer system
and outputs are the data and signals which are sent by it as result after processing the input.
The output devices display the result of input data or signals after processing it. Examples of
these could be your computer’s monitor, which displays all the programs which are running into
the computer, as well as the printer, which will print out a hard copy of the information which is
saved in your computer.
Input and output devices allow the computer system to interact with the outside world by moving
data into and out of the system. An input device is used to bring data into the system. Examples
of some input devices are:

• Keyboard
• Mouse
• Joystick
• Microphone

• Barcode reader
• Graphics tablet
An output device is used to send data out of the system. Examples of some output devices are:

• Monitor
• Printer
• Plotter
• Speaker

Input and output devices in short are also called I/O devices. They are directly connected to an
electronic module called I/O module or device controller. For example, the speakers of a

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