Classification and generations of computers
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Transcript of Classification and generations of computers
Introduction to computers Classifications of computers (1)By nature (2)By purpose (3)By size Generations(5)
Computers
Digital ComputersDigital Computers Analog ComputersAnalog Computers
Hybrid computersHybrid computers
Classification by nature
Digital Computers
Use digits specially binary digits (0, 1) to represent data
Examples:
Personal computers such as Laptops and Desktops, etc
Computer Classification
Classification by nature
Analog Computers
Use physical magnitudes as voltage and pressure instead of digits
Examples:
Thermometers, voltmeters, speed measuring meters, etc
Computer Classification
Classification by nature
Hybrid Computers
Combination of both the analogue and digital computers
Examples: A computer that maintain temperature in a burner of a production plant
Computer Classification
Classification by nature
Computer Classification
Classification by Purpose
Special purpose Special purpose computerscomputers
General purpose General purpose computerscomputers
Computers
Special purpose computers
› Designed for a special job only
› Examples: Computers used in digital watches, pocket calculators, point of sales, etc
Computer Classification
Classification by Purpose
General Purpose computers
› Design to solve wide variety of problems
› Examples: A personal computer used in an office or at home
Computer Classification
Classification by Purpose
Can a general purpose computer Can a general purpose computer be converted to a special purpose computer ?be converted to a special purpose computer ?
By size
Mainframe
Minicomputers
Microcomputers
Supercomputer
Mainframe computer
› A large computer › has enormous input, process, output and
storage capacities › hundreds of terminals connected › hundreds of users can work simultaneously
Computer Classification
Classification by size
Mini computer
A smaller version of Mainframes
Computer Classification
Classification by size
Computer Classification
Classification by size
MicrocomputerMicrocomputer
A smaller computerA smaller computer
available for only one user at any time available for only one user at any time
The central processing unit is embedded The central processing unit is embedded in a single chip - in a single chip - microprocessormicroprocessor
Examples: personal computers; Examples: personal computers; Laptops, desktopsLaptops, desktops
The First generation
The Second Generation
The Third Generation
The Fourth Generation
The Fifth Generation
1942-1955 Vacuum Tube
› Heat› Burnout
Machine language
Magnetic core memory
Storage› Punched cards› Tape (1957)
Characteristics of 1st Generation Computers Computers big and clumsy Electricity consumption is high Electric failure occurred regularly - computers not very reliable Large air conditioners was necessary because the computers generated heat Batch processing
1942-1955
1942-1955
1955-1964 Transistor
› Smaller› No warm-up time› Less energy› Less heat› Faster› More reliable
Storage› Removable disk pack
(1954)› Magnetic tape
Programming languages› Assembly language› FORTRAN (1954)› COBOL(1959)
Used primarily by business, university, government
Computers became smaller Generate less heat Electricity consumption lower More reliable and faster Core memory developed Magnetic tapes and disks used First operating systems developed A new processing method was needed. Time-sharing (processing
technique)
1955-1964
1964-1975 Integrated Circuit
› Electronic circuit on small silicon chip
› Reliability› Compactness› Low cost› Inexpensive –
mass-produced
1. Computers smaller, faster and more reliable
2. Power consumption lower
3. High-level languages appeared
1975-1989 Microprocessor
› General-purpose processor on a chip
Explosive growth› Digital watches› Pocket
calculators› Personal
computers› Cars› Copy machines› Television sets
• Integrated circuits, smaller and faster
• Micro computer series such as IBM and APPLE developed
• Portable computers developed • Great development in data
communication
• Different types of secondary memory with high storage capacity and fast access
developed
1975-1989
1989-Present Large capacity of
main memory, hard disk, optical disk.
Notebook Powerful desktop
P.C and workstation Very powerful
mainframe systems
Internet World wide web
(www) ,multimedia applications
Portable computers, more powerful ,cheaper ,reliable and easy to use.
1989 - today