Fourth Generation (1972-1984)
The next generation of computer systems used the large scale integration (LSI -1000 devices per chip) and very large scale integration (VLSI - 100,000 devices perchip) in the creation of computing elements. At this rate entire processors will fit on a single chip, and for simple systems the whole computer (processor, main memory and I/O controllers) can fit onto one chip. Gate delays dropped to around1ns per gate.
Developments in software include very high level languages such as FP (functionalprogramming) and Prolog (programming in logic) started. These languages lean to use a declarative programming style as in contrast to the imperative style of Pascal, FORTRAN, C, et al.