Generation of Computer

Each generation of computer is characterized by a major technological development that fundamentally changed the way computers operate, resulting in increasingly smaller, cheaper, more powerful and more efficient and reliable devices.

First Generation (1940-1956) Vacuum Tubes

First Generation of computer was introduced by the Charles Babbage. These computers used vacuum tubes as the main component & also used for memory. If any problem arises in the computer, it is very difficult to debug as the computer uses more than 20,000 thousand vacuum tubes in a single computer. They were often enormous in size, taking up entire rooms. These computers are so expensive that only country has the computer.

Some of its features are :

• Basic arithmetic operations took few milliseconds.
• Bulky in size, takes entire room.
• Single vacuum tube can store only 4Kb.
• Consume more power with limited performance.
• High cost .
• Uses machine level language for execution, the lowest-level programming language understood by computers.
• They could only solve one problem at a time.
• Mercury delay line memories and Electrostatic memories were used.
• Punched cards and paper tape were invented to feed programs and data and to get results.
• Mainly used for scientific computations. 
• UNIVAC and ENIAC computers are examples of first-generation computing devices.

Second Generation (1956-1963) Transistors
Development of the transistors was the major change of second generation of computer. Single Transistors replaced 2000vacuum tubes. The transistor was invented in 1947 but did not see widespread use in computers until the late 1950s. The transistor was far superior to the vacuum tube, allowing computers to become smaller, faster, cheaper, more energy-efficient and more reliable than their first-generation predecessors.

Some of its features are:

• Transistors were used in place of vacuum tubes
• Small in size
• Lesser power consumption and better performance
• Lower cost
• Magnetic ferrite core memories were used as main memory which is a random-access nonvolatile memory
• Magnetic tapes and magnetic disks were used as secondary memory
• Second-generation computers moved from cryptic binary machine language to assembly languages, which allowed programmers to specify instructions in words.
• High-level programming languages were also being developed at this time, such as early versions of COBOL and FORTRAN.
• First computers that stored their instructions in their memory.