First Generation Computers
1946-1959 - use of vacuum tubes
1954 - introduction of IBM 650
Second Generation Computers
Invention of the transistor which were smaller, more reliable and less expernsive and gave off less heat than vacuum tubes. IBM's popular 7000 series of large-scale computers
Third Generation Computers
Introduction of the integrated circuit which packed in many transistors.
April, 1964 - IBM System/360 was introduced with larger and upgradable memory using the IBM OS; an operating system to control the actions of the computer.
Fourth Generation Computers
Not sure when the the fourth generation began but we are in it. Notable is the increase in memory size and processing speed.
1971 introduction of the first microprocessor by Intel Corporation, and the rest is history!. (see Table)
Chip Introduction No. of Speed
date transistors
4004 1971 2,300 [0.06 MIPS]
8008 1972 3,500
8080 1974 6,000 [0.6 MIPS]
8086 1978 29,000
8088 1979 29,000
i286 1982 134,000 [1 MIPS]
i386 1985 275,000 [5 MIPS]
i486 1989 1,200,000 [20 MIPS]
Pentium 1993 3,100,000 [100 MIPS]
Pentium Pro 1995 5,500,000
Pentium II 1997 7,500,000 [266 MIPS]*
Pentium III 1999 9,500,000 [500 MIPS]*
Pentium 4 2000 12,000,000 [1500 MIPS]*
MIPS - millions of instructions or operations per
second
* For Pentium II, III & 4 - megaHertz (millions of
cycles per second)
Kilobyte = 1000 bytes (1 thousand)
Megabyte = 1,000,000 bytes (1 million)
Gigabyte = 1,000,000,000 (1 billion)
Terabyte = One trillion bytes