History of Computers Teacher: Ms. Hall

Reference site: History of Computer generation's of computer (HQ) - YouTube

Investors of Early Computers Abacus The Pascaline Machine- Blaise Pascal and Gottfried Wihelm Leibnez The Babbage Machine (Analytical Engine)- Charles Babbage The Automatic Loom (Hollerith Machine)- Herman Hollerith

USES OF EARLY COMPUTING DEVICES Pascaline- Used by scientists and mathematicians (additions and subtraction) Abacus- Used in schools, offices, shops (calculations/payroll) Automatic Loom- (census) Analytic Engine- (calculations)

THE PASCALINE

THE ABACUS

THE AUTOMATIC LOOM

THE ANALYTICAL ENGINE

FIRST GENERATION

SECOND GENERATION

THIRD GENERATION

FOURTH GENERATION

Generation of Computers First Generation ( ) Second Generation ( ) Third Generation ( ) Fourth Generation (1971- present) Vacuum TubesTransistorsIntegrated CircuitsMicroprocessors Big and Clumsy High electricity consumption Larger AC were needed Lot of electricity failure occurred. Transistors were used Core memory was developed. Faster than first generation computers. Integrated circuits developed Power consumption was low. 100 times faster than the second generation. Development of portable computers Floppy disks became the more popular storage medium.

Super Computer Supercomputers – are the largest, fastest and most powerful computers at present.

Mainframe Computers Mainframe Computers are very expensive and can handle more than hundred users at a time. They are found in large organization such as Banks.

Microcomputer This type of computers include; systems that are for general purpose and for business needs. They are usually called PC’s (Personal Computers) based on the microprocessor. Examples are desktop computers, laptop, notebook etc

Mini Computers Have become outdated and are rarely used today. They were very popular in the 1960s. They take up less space, may fit on a desk or take up the space of filing cabinet.

Types of Computer Characteristics /Features SupercomputerMicrocomputerMainframeMinicomputer Design or Architecture Developed by International Business. They are equivalent to two basketball courts. Microcomputer also known as personal computers Mainframes vary in size. They are small, they can fit on a desk or be as big as a large filing cabinet Speed at which instructions are carried out It’s the fastest, most powerful and most expensive computer currently available. They process data at millions of instructions per second. It can process a number of applications at the same time Amount of main memory The main memory is measured in million of bytes. They store millions of bytes, instructions and information. Number of users/uses Scientific application, analysis of geological data, nuclear energy research and meteorology, One person generally uses the computer at a time Used by government agencies, banks, hospitals etc. They can serve up to 4000 users connected.

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