evolution of computer

Name: Lee Long Kiat
Metric .no: KJC0870131
Course code: CMB1003
Course Name: Computer Organization and Architecture
Section Number: 2
Date of Submission:19/8/2008


Assignment 1: The evolution of computer

· From 1945 to 2008, the generation of computer had been developed to fourth generation. The information below show that the information of every generation computer.

First generation -------vacuum tubes 1946-1958 (The Vacuum Tube Years)


First Generation computers are characterized by the use of vacuum tubes. ENIAC it means Electronic Numerical Integrator And Computer. The first vacuum tube computer, ENIAC, was developed by US army ordinance to calculate ballistic firing tables in World War II. The machine weighed 30 tons, covered about 1000 square feet of floor, and consumed 130 or 140 kilowatts of electricity. It programmed manually by switches.

The vacuum tubes computer is huge machine contents thousand of vacuum tubes. It needs a big room to content itself. It was very huge, slow, expensive, and often undependable. As we can see that the vacuum tubes are very easy overheating.


This is a vacuum tube which is overheating. Leaving a black stain on the inside of the glass tube. Constant overheating and burnout in the vacuum tubes of ENIAC, the first electronic computing device, in 1947 led AT&T Bell Telephone Laboratory engineers John Bardeen, William Shockley, and Walter Brattain to seek out a suitable alternative for the commercially unreliable vacuum tube. As we can know that this is the weakness of the vacuum tube computer.



Second generation-------transistor 1959-1964 (The Era of the Transistor)

In 1947 three scientists, John Bardeen, William Shockley, and Walter Brattain working at AT&T's Bell Labs invented what would replace the vacuum tube forever. This invention was the transistor which functions like a vacuum tube in that it can be used to relay and switch electronic signals.

The difference between first generation and second generation computer:


First generation—vacuum tube
Second generation-transistor
Process speed
Slow
fast
Weight
Heavy
Light
Size
Large
small
Overheating
Yes
no
Replacement cost
expensive
cheap
Compare
1 transistor = 40 vacuum tubes
Table 1

As we can see from the table 1, the comparison of both computers we know that the qualification of second generation computer is better than the first generation computer.
It got more complex arithmetic and logic unit (ALU) and control unit (CU), so it got condition to do high level programming languages, such as early versions of COBOL and FORTRAN.
Second generation computer is the first computer that store their instructions in their memory, which moved from a magnetic drum to magnetic core technology.


Transistor
Transistor is made from the silicon. It is a abundant material can be find in beach sand and glass easily. Therefore it is very cheap to produce the transistor. The transistor was found to conduct electricity faster and better than vacuum tubes.








Third generation -------Integrated Circuit 1965-1970 (Integrated Circuits - Miniaturizing the Computer)

Transistors were a tremendous breakthrough in advancing the computer. In third generation computer the transistors were miniaturized and placed on silicon chips, called semiconductors, which drastically increased the speed and efficiency of computers. This is a big change in the computer technology, because the size becomes smaller than the second generation computer.
Chip

A chip is a small piece of semiconducting material (usually silicon) on which an integrated circuit is embedded. It can contents about thousand up to millions of transistor onto the silicon of water.

Compare with previous 2 generation computer

Third generation computer
Previous generation computer
Function
Many
less
Size
tiny
huge
Produce cost
cheap
expensive
Speed
fast
slow

The function of the integrated circuit computer:
· Data storage-provided by memory cells
· Data processing-provided by gates
· Data movement-the paths between components that are used to move data
· Control-the paths between components that carry control signals

The function shows at top that mean the third generation is nearly similar with our PC now.
These third generation computers could carry out instructions in billionths of a second. The size of these machines dropped to the size of small file cabinets. Yet, the single biggest advancement in the computer era was yet to be discovered.


Fourth generation-------microprocessors 1971-Today (The Microprocessor)

The computer development came to this generation the computer become smaller and light.
This generation can be characterized by both the jump to monolithic integrated circuits (millions of transistors put onto one integrated circuit chip) and the invention of the microprocessor (a single chip that could do all the processing of a full-scale computer). By putting millions of transistors onto one single chip more calculation and faster speeds could be reached by computers. Because electricity travels about a foot in a billionth of a second, the smaller the distance the greater the speed of computers.

However what really triggered the tremendous growth of computers and its significant impact on our lives is the invention of the microprocessor. Ted Hoff, employed by Intel (Robert Noyce's new company) invented a chip the size of a pencil eraser that could do all the computing and logic work of a computer. The microprocessor was made to be used in calculators, not computers. It led, however, to the invention of personal computers, or microcomputers.




Intel's superscalar successor to the 486 was introduced on March 22,1993. It has two 32-bit 486-type integer pipelines with dependency checking. It can execute a maximum of two instructions per cycle. It does pipelined floating-point and performs branch prediction. It has 16 kilobytes of on-chip cache, a 64-bit memory interface, 8 32-bit general-purpose registers and 8 80-bit floating-point registers. It is built from 3.3 million transistors on a 262.4 square mm die with ~2.3 million transistors in the core logic. Its clock rate is 66MHz, heat dissipation is 16W. In burst mode, the Pentium loads 256 bits of data into its 16K on-board cache in one clock cycle. It is called "Pentium" because it is the fifth in the 80x 86 lines. It would have been called the 80586 had a US court not ruled that you can't trademark a number. The successors are the Pentium Pro and Pentium II. A floating-point division bug was discovered in October 1994.