If one thinks about it, it is truly remarkable how far the technology has advanced since the first digital computer was introduced in 1946. The ENIAC (Electronic Numerical Integrator and Calculator) was designed and built at the University of Pennsylvania. It weighed 30-tons and took up 1500 square feet of floor space. The first computer developed in Europe was the EDSAC (Electronic Delay-Storage Automatic Computer). This machine was built at Cambridge University in 1949. What characterized these earliest machines is that the switching and control functions were handled by vacuum tubes. This feature typifies what is termed the first-generation of computers. EDSAC had one feature that ENIAC lacked. Within the computer was stored the instructions to control the machine and the data to be operated upon. This was the first of the stored program computers. The first commercially available digital computer was the Sperry Rand UNIVAC I. This was sold to the Bureau of the Census and put in place in 1951.In the late 1950's the bulky and hot vacuum tubes were replaced in computer designs by smaller, more reliable solid state transistors. The use of transistors as the basic component of computer design characterizes what is known as the second generation of computers.1963 brought about the start of third-generation computers. Solid-logic technology (SLT) enabled the development of the integrated circuit (IC). ICs allowed the placement of as many as 664 transistors, diodes and other associated components on silicon chip less than one eighth of an inch square.We are now in the midst of the fourth-generation of computers. Characterized by continued miniaturization of circuitry, such developments as large-scale integration (LSI) and very large-scale integration (VLSI) have enabled the current crop of machines to have a level of power and speed that was almost unimaginable 20 years ago.Now on to the history of the microcomputer. The first commerciall...
