Background
The idea of a computer goes back to invention of abacus in Asia Minor, 5000 years ago. More recently, there were developments in past two centuries that are foundation (Charles Babbage, father of computers, 1791) of what we call a computer today. However, basis for what we call a modern digital computer dates back to 1940s introduced “John von Neumann (Virtual Machines)” of two key concepts:
1. a virtual ‘memory’ to hold a stored ‘program’ & ‘data’
2. ‘conditional branching’.
These two ideas are foundation of CPU – heart of computers.
Starting with Von Neumann, there were a series of key advances that led to computers powerful enough to be used for DIP.
Briefly, advances may be summarized as follows:
1. invention of transistor (William Schockly, 1941; 1948 (?)) by Bell Laboratories in 1948 (William Schockly);
2. development in 1950s & 1960s of high-level PL’s, eg., COBOL and FORTRAN;
3. invention of- integrated circuits (ICs) at Texas instruments in 1958;
4. development of operating systems in the early 1960s;
5. development – “processor (single chip consisting of CPU, memory, I/O device controls, etc.) by Intel in early 1970s;
6. introduction by IBM – PC in 1981; &
Progressive miniaturization of components, starting e large scale integration (LI) in late 1970s, then very large scale integration (VLSI) in 1980s, to – present use of ultra large scale integration (ULSI) i.e., super large scale integration (SLSI ?).