SCHOOL OF BIO AND CHEMICAL ENGINEERING
DEPARTMENT OF BIOTECHNOLOGY
UNIT – I - BASICS OF COMPUTERS – SBC1202
1
, Introduction to Computer
A computer is an electronic device, operating under the control of instructions stored
in its own memory that can accept data (input), process the data according to specified rules,
produce information (output), and store the information for future use.
Functionalities of a computer2
Any digital computer carries out five functions in gross terms:
Computer Components
Any kind of computers consists of HARDWARE AND SOFTWARE.
Hardware:
Computer hardware is the collection of physical elements that constitutes a computer system.
Computer hardware refers to the physical parts or components of a computer such as the
monitor, mouse, keyboard, computer data storage, hard drive disk (HDD), system unit (graphic
cards, sound cards, memory, motherboard and chips), etc. all of which are physical objects that
can be touched.3
2
,Input Devices
Input device is any peripheral (piece of computer hardware equipment to provide data and
control signals to an information processing system such as a computer or other information
appliance.
Input device Translate data from form that humans understand to one that the computer can work
with. Most common are keyboard and mouse
3
, Example of Input Devices:-
1. Keyboard 2. Mouse (pointing device) 3. Microphone
4. Touch screen 5. Scanner 6. Webcam
7. Touchpads 8. MIDI keyboard 9.Electronic Whiteboard
10.Graphics Tablets 11.Cameras 12.Pen Input
13.Video Capture Hardware 14.Microphone 15.Trackballs
16.Barcode reader 17.Digital camera 18.Joystick
19.Gamepad
Note: The most common use keyboard is the QWERTY keyboard. Generally standard
Keyboard has 104 keys.
Central Processing Unit (CPU)
A CPU is brain of a computer. It is responsible for all functions and processes. Regarding
computing power, the CPU is the most important element of a computer system.
The CPU is comprised of three main parts :
* Arithmetic Logic Unit (ALU): Executes all arithmetic and logical operations. Arithmetic
calculations like as addition, subtraction, multiplication and division. Logical operation like
compare numbers, letters, or special characters
* Control Unit (CU): controls and co-ordinates computer components.
1. Read the code for the next instruction to be executed.
2. Increment the program counter so it points to the next instruction.
3. Read whatever data the instruction requires from cells in memory.
4. Provide the necessary data to an ALU or register.
5. If the instruction requires an ALU or specialized hardware to complete, instruct the
hardware to perform the requested operation.
* Registers :Stores the data that is to be executed next, "very fast storage area".
Primary Memory:-
1. RAM: Random Access Memory (RAM) is a memory scheme within the computer system
responsible for storing data on a temporary basis, so that it can be promptly accessed by the
processor as and when needed. It is volatile in nature, which means that data will be erased
once supply to the storage device is turned off. RAM stores data randomly and the processor
4
DEPARTMENT OF BIOTECHNOLOGY
UNIT – I - BASICS OF COMPUTERS – SBC1202
1
, Introduction to Computer
A computer is an electronic device, operating under the control of instructions stored
in its own memory that can accept data (input), process the data according to specified rules,
produce information (output), and store the information for future use.
Functionalities of a computer2
Any digital computer carries out five functions in gross terms:
Computer Components
Any kind of computers consists of HARDWARE AND SOFTWARE.
Hardware:
Computer hardware is the collection of physical elements that constitutes a computer system.
Computer hardware refers to the physical parts or components of a computer such as the
monitor, mouse, keyboard, computer data storage, hard drive disk (HDD), system unit (graphic
cards, sound cards, memory, motherboard and chips), etc. all of which are physical objects that
can be touched.3
2
,Input Devices
Input device is any peripheral (piece of computer hardware equipment to provide data and
control signals to an information processing system such as a computer or other information
appliance.
Input device Translate data from form that humans understand to one that the computer can work
with. Most common are keyboard and mouse
3
, Example of Input Devices:-
1. Keyboard 2. Mouse (pointing device) 3. Microphone
4. Touch screen 5. Scanner 6. Webcam
7. Touchpads 8. MIDI keyboard 9.Electronic Whiteboard
10.Graphics Tablets 11.Cameras 12.Pen Input
13.Video Capture Hardware 14.Microphone 15.Trackballs
16.Barcode reader 17.Digital camera 18.Joystick
19.Gamepad
Note: The most common use keyboard is the QWERTY keyboard. Generally standard
Keyboard has 104 keys.
Central Processing Unit (CPU)
A CPU is brain of a computer. It is responsible for all functions and processes. Regarding
computing power, the CPU is the most important element of a computer system.
The CPU is comprised of three main parts :
* Arithmetic Logic Unit (ALU): Executes all arithmetic and logical operations. Arithmetic
calculations like as addition, subtraction, multiplication and division. Logical operation like
compare numbers, letters, or special characters
* Control Unit (CU): controls and co-ordinates computer components.
1. Read the code for the next instruction to be executed.
2. Increment the program counter so it points to the next instruction.
3. Read whatever data the instruction requires from cells in memory.
4. Provide the necessary data to an ALU or register.
5. If the instruction requires an ALU or specialized hardware to complete, instruct the
hardware to perform the requested operation.
* Registers :Stores the data that is to be executed next, "very fast storage area".
Primary Memory:-
1. RAM: Random Access Memory (RAM) is a memory scheme within the computer system
responsible for storing data on a temporary basis, so that it can be promptly accessed by the
processor as and when needed. It is volatile in nature, which means that data will be erased
once supply to the storage device is turned off. RAM stores data randomly and the processor
4
