Second Generation of Computer

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Second Generation Computer (1955-1964):-

A big revolution in electronics took place with the invention of transistors by Bardeen, Brattain and Shockley at the Bell Telephone Laboratories in 1947.Transistors made of the germanium semiconductor material ware highly reliable compared to vacuum tubes since transistors had no filament to burn. They occupied less space and used only a tenth of the power required by vacuum tubes.  They also could switch from a 0 to a 1 state in a few microseconds, about tenth of the time needed by tubes. Thus, switching circuits for computers made with transistors were about ten times more reliable, ten times faster, dissipated one-tenth the power occupied about one-tenth the space and were ten times cheaper than those using tubes. Computers manufacturers thus chanced over to transistor from tubes. The second generation computers emerged around 1955 with the use of transistors instead of vacuum tubes in computers. This generation lasted till 1965.

Another major event during this period was the invention of magnetic cores for storage. Magnetic cores are tiny rings (0.05 cm diameter) made of ferrite and can be magnetized in clockwise or anticlockwise direction. The two directions are used to represent a 0 or a 1. Magnetic cores were used to construct large random access memories. Memory capacity in the second generation was about 100 KB. Magnetic disk storage was also developed in this period.

The higher reliability of computers and large memory availability led to the development of high level languages. FORTRAN, COBOL, ALGOL, SNOBOL were developed during this generation. With higher speed CPUs and the advent of magnetic tape and disk storage operating systems were developed. Good batch operating systems, particularly the use ones on IBM 7000 series computers, emerged during the second generation.

Commercial applications rapidly developed in this period and dominated computer use by mid-1960s. More than 80% installed computers were used in business and industry. All systems were batch oriented. Payroll, inventory control, marketing, production planning and general leader systems were developed. A number of applications of operations research such as Linear Programming, Critical Path methods (CPM) and Simulation became popular. Engineering applications, particularly in process control, increased rapidly.
New professions in computing such as system analyst and programmers emerged during the second generation. Academic programmes in computer science also initiated.

The characteristics features of second-generation computers are as follows:

1. They were more than ten times faster than the first- generation computers.

2. They were much smaller than first-generation computers, requiring smaller space.

3. Although the heat dissipation was much less than first-generation computers, the room/areas in which the second-generation computers were located had to be properly air-conditioned.

4. They consumed much less power than the first-generation computer.

5. They were more reliable and less prone to hardware failure than the first-generation computers.

6. They had faster and larger primary and secondary storage as compared to first-generation computers.

7.  They were much easier to program and use than the first-generation computers. Hence, they had wider commercial use.

8. In these computers, thousands of individual transistors had to be assembled manually by hand into functioning circuits. Hence, commercial production of these computers was difficult and costly.

9. Second generation computers has faster input /output devices.

10. Assembly languages was used for programming.

Advantages of Second Generation Computers

1. They were smaller in size as compared to first generation computers.
2. They were more reliable than first generation computers.
3. They consume less power and produce less heat than that of first generation computers.
4. These computers can perform computation tasks in microseconds.
5. Hardware failure was decreased as there were in first generation computers.
6. They could be taken from one place to another.
7. Their commercial use was wider than that of first generation computers.

Disadvantages of Second Generation Computers

1. As the first generation computers needed air conditioning, second generation computers also needed air conditioning.
2. Frequent maintenance was required.
3. Manual assembly of individual component into functioning was still required.
4. Its commercial production was difficult and costly.

Examples of second generation computers

  PDP-8, IBM 1401 and CDC 1604 etc.