2. First calculation device is Abacus (a wooden
frame with balls strung on parallel wires).
Invented in china in pre-Christian times.
Used by Greeks, Romans and Chinese.
Storage is limited to a single number.
Semi-mechanical calculator.
3. In 1642, Blaise Pascal invented a machine called
Pascal machine.
Able to add and subtract.
Multiplications and divisions were carried out as
a series of addition and subtraction.
Numbers were entered by dialing a series of
numbered wheels and a series of toothed wheels
transferred the movements to a dial, which
showed the result.
4. In 1671, Leibnitz invent a machine that can
1. Perform multiplication and divisions
2. Use the same principles of Pascal.
In 1822, Charles Babbage devised a machine
called Difference Engine that can perform
Trigonometric and Logarithmic tables.
Later he proposed an Analytical engine which
had-
1. A punch card reader.
2. A memory unit.
3. An arithmetic unit. and
4. An automatic printout.
5. Babbage was not in a condition to build his
proposed machine but he is the prototypist of
computers we are now using.
For this reason he is often called the inventor
of modern computer.
And Ada Lovelace( Daughter of Bible)
programmed the proposed machine; she is
the first computer programmer with no
doubt.
6. The first machine we called computer is Mark-I.
Started in 1937 and finished in 1944.
Invented at Harvard University inspired by the
need of heavy computations during world war II.
It was 15m long, 2.4m height, 0.6m wide.
Todays desktop computer can be well mounted
on a small table and much faster than the Mark I.
7. Atanosoff working at lowa state university
with a graduate student Berry developed
‘ABC’.
Contains Vacuum tubes as main switching
mechanism instead of electromagnetic relay
as in Mark I.
Hundreds time faster than Marks I.
8. First Electronic computer was ENIAC (Electronic
Numerical Integrator And Calculator).
1. Completed in 1946 in university of Pennsylvania.
2. Had 47 electronic sections and each section was 9 feet
high, 2 feet wide and 1 feet deep.
3. Weight 30 tons.
4. Occupied 15000 square feet.
5. Perform 5000 additions per second.
6. Consumed 150 kw of power.
7. Need to be water cooled. And
8. Continued to function 9 years.
9. Moore school personnel and ballistic research lab
of US ARMY built a computer named EDVAC
(Electronic Discrete Variable Automatic
Computer) based on Von Neumann’s idea.
Neumann was the first to introduce the stored
program concept in a computer.
It takes 3 years from 1947 to 1950.
Another computer using internal storage called
EDSAC (Electronic Delay Storage Automatic
Computer).
10. First Generations (1944-1958):
1. Used Vacuum tubes.
2. Bulky.
3. Used great amount of electric power.
4. Generate a great deal of heat.
5. Not very reliable.
6. 3000 to 5000 additions per second.
11. Used transistors (invented in 1948 at Bell lab).
Much faster than its predecessor.
Generate much less heat.
Small size, less expensive, required power.
More reliable.
Faster input output.
Better programming ability.
Greater capacity and faster storage.
Able to transfer data to other computers at greater
distances over telephone lines.
2000 to 50000 additions per seconds.
12. Used IC (Integrated Circuit) invented in 1957.
Small size, greater capacity, less power.
Perform as many as 10 million additions per
seconds.
13. Used microprocessor (programmable very
large scale integrated circuit).
Microprocessor consist of thousands of
transistors.
Pentium processor has 5 millions transistors.
14. Some people say that fifth generation computers
will be:
◦ Faster operating speed.
◦ Virtually unlimited memory.
Other say:
◦ Circuitry based on superconductors.
Other still say:
◦ Incorporate hundreds or thousands of processors
operate in parallel.
15. There is much more to evaluating hardware than
determining the fastest and cheapest computing device.
PC evaluating factors:
1. Performance: What is its speed, capacity, and throughput?
2. Cost: What is its purchase price? What will be the cost of
operation and maintenance?
3. Reliability: What are the risk of malfunction and its maintenance
requirement?
4. Compatibility: Is it compatible with existing hardware and
software?
16. 5. Technology: In what year of its product life cycle is it?
6. Ergonomics: Is it user friendly designed to be safe,
comfortable and easy to use?
7. Connectivity: Can it be easily connected to wide area
network and local area network?
8. Scalability: Can it handle the processing demands of a
wide range of users?
9. Software: Is system and application software available
that can best use this hardware?
10. Support: Are the service required to support and maintain
it available?
