18-08-2012, 02:49 PM
Welcome to the world of computer
computer.ppt (Size: 8.4 MB / Downloads: 233)
What is a computer
An electronic device that is designed to accept and store
data , process them and produce output following a step
by step of instructions. In short it is a device having
Processing power
Memory
CLASSIFICATION OF COMPUTERS
Until recently, computers classified as micro computers, mini computers, super computers and mainframes.
Now a days PCs are classified on the basis of mode of use as desktops and laptops.
Microelectronics
Literally - “small electronics”
A computer is made up of gates, memory cells and interconnections
These can be manufactured on a semiconductor
e.g. silicon wafer
Generations of Computer
Vacuum tube - 1946-1957
Transistor - 1958-1964
Small scale integration - 1965 on
Up to 100 devices on a chip
Medium scale integration - to 1971
100-3,000 devices on a chip
Large scale integration - 1971-1977
3,000 - 100,000 devices on a chip
Very large scale integration - 1978 to date
100,000 - 100,000,000 devices on a chip
Ultra large scale integration
Over 100,000,000 devices on a chip
A More Detailed List of Components
Micro processor
Mother Board
Chip Set
BIOS
Memory
Buses and ports
I/O Devices
Removable Devices
Power Supply
Computer Organization
CPU - central processing unit
Where decisions are made, computations are performed, and input/output requests are delegated
Memory
Stores information being processed by the CPU
Input devices
Allows people to supply information to computers
Output devices
Allows people to receive information from computers
CPU
Brains of the computer
Arithmetic calculations are performed using the Arithmetic/Logical Unit or ALU
Control unit decodes and executes instructions
Arithmetic operations are performed using binary number system
Control Unit
The fetch/execute cycle is the steps the CPU takes to execute an instruction
Performing the action specified by an instruction is known as executing the instruction
The program counter (PC) holds the memory address of the next instruction