The need to perform complex calculations has culminated the computer from its mechanical roots of relays and moving parts. While calculating devices have been around since around 3000 B.C. C., modern computer technology has its roots in the 16th and 17th centuries. The evolution of computers is often classified in generations. It is relevant to point to a period before these, a “generation 0” between 1640 and 1940 whose machines were mechanical devices (eg relays and gears), including Pascal’s Pascaline, the first mechanical calculator.

computer generations

First generation vacuum tubes (1945-1959)

Relays were replaced by vacuum tubes that had no moving parts, therefore faster, hybrids of both were eventually built. The first electronic computers were COLOSSUS (1943, although not publicly recognized) and ENIAC (1946), which contained 18,000 vacuum tubes and 1,500 relays. Also notable was the UNIVAC, which became the first commercially available computer.

Second generation transistors (1960-1965)

Vacuum tubes replaced by transistors (invented at Bell Labs in 1948). High-level programming languages ​​developed; FORTRAN and COBOL among others. Transistors were much smaller, cheaper to make, and much more reliable than tubes.

Third generation integrated circuits (1965-1971)

Machine speeds went from the microsecond to the picosecond range (trillions). Terminals replaced punch cards for data entry. This era saw the rise of operating systems and the mass production of circuits. IBM introduced a family of compatible computers

Fourth generation (1973-) VLSI – Very Large Scale Integration

It allowed thousands of transistors to be incorporated on a chip, giving rise to the microprocessor, a processor on a chip. These reduced the price of computers giving rise to personal computing.

The 1990s saw the advancement of the Fourth Generation in ULSI (Ultra Large Scale Integration) with millions of transistors per chip. In 1965, Gordon Moore of Intel predicted that “the number of transistors in an integrated circuit will double every 18 months.”

Fifth generation (1985- ) Networks and parallel processing

Still a generation debated. How high-end machines (eg web servers) can have multiple CPUs and interconnectivity between computers; networks