Second Generation (1959-1964)
"As long as we can make them smaller, we can make them faster."
-Seymour Cray, Developer of the CDC Series Computers
The Vacuum Tube's Replacement
Second generation computers can be characterized largely by
their use of transistors. They replaced
the job of vacuum tubes through the 1950s and 1960s. Vacuum tubes generated too much heat, were very large, and proved
to be unreliable. Ultimately, they served as an update for using less power and
space. It acted as a transmitter and resistor (ergo its name; ‘trans’, ‘istor').
Its inventors were scientists at
the Bell Telephone Laboratories in New Jersey. John Bardeen, William Shockley, and
Walter Brattain wanted to make a more efficient and useful amplifier, and in
1952, a transistor was first put to use as a Sonotone hearing aid.
Computers of this generation essentially used magnetic cores for primary storage and magnetic disks/ tape for secondary memory.
Computers of this generation essentially used magnetic cores for primary storage and magnetic disks/ tape for secondary memory.
Transistors Used in Computers; IBM 7000 Series
The IBM 7000 series was developed throughout the 1950s and
early 1960s. They were labeled as computers for “large scale scientific and
technological applications.” These computers were much more compatible compared
to the IBM 700 series because of their use of transistors. They had higher input/
output speed, using disk and tape. Languages supported by the computers’
operating systems included FORTRAN, COBOL, SORT/MERGE, etc.
Other Transistorized Computers; CDC Computers
Designed by Seymour Cray and others at Control Data
Corporation, the CDC 1604 is credited as one of the first successfully
transistorized computers. In 1960, the first 1604 was delivered to the US Navy,
and by 1964 more than fifty were built. They used 48-bit words of magnetic core
memory, and each 48-bit contained 24-bit instructions. In 1604, the CDC 3000 series succeeded the
1604. All second generation CDC computers used core memory.
UNIVAC 1107
The new UNIVAC series began with UNIVAC 1107 made my Sperry Rand in 1962. The second generation computer UNIVAC was still quite massive, but very quiet. Its central processor was 36-bit architecture, which was able to perform arithmetic equations in one 4- microsecond cycle time. It printed cards 600 lines per minute but was known for jamming. All executions were started by reading punch cards. Memory access time was eight microseconds per word. Soon came the UNIVAC 1108, which would mark the start of the third generation.
What defines Generation 2?
Characteristics of the second generation include:
Some computers of the second generation include:
- Use of Transistors
- Smaller than 1st Generation
- Still Fairly Expensive
- More Reliable than 1st Generation
- Less Electric Consuming
- Faster
- Supports Machine and Assembly Computer Languages
- Punch Cards/ Printouts
Some computers of the second generation include:
- IBM 7000 Series
- CDC 1620
- CDC 3000 Series
- UNIVAC 1107