ENIAC (Electronic Numerical Integrator and Computer) was the first computing system designed in the early 1940s. It consisted of 18,000 buzzing electronic switches called vacuum tubes, 42 panels each 9'x 2'x1'. It was organized in U-Shaped around the perimeter of a room with forced air cooling.

• Atanasoff-Berry Computer (ABC) design was known as the first digital electronic computer (though not programmable). It was designed and built by John Vincent Atanasoff and his assistant, Clifford E. Berry in 1937.
• In 1941, Z3 was invented by German inventor Konrad Zuse. It was the first working programmable, fully automatic computing machine.
• Transistors were invented in 1947 at Bell Laboratories which were a fraction the size of the vacuum tubes and consumed less power, but still, the complex circuits were not easy to handle.
• Jack Kilby and Robert Noyce invented the Integrated Circuit at the same time. In July 1959 Noyce filed a patent for this.
• In 1968, Robert Noyce co-founded Intel Electronics company which is still the global market leader in IC manufacturing, research, and development.
• In 1983, Lisa was launched as the first personal computer with a graphical user interface (GUI) that was sold commercially; it ran on the Motorola 68000, dual floppy disk drives, a 5 MB hard drive and had 1MB of RAM.
• In 1990, Apple released the Macintosh Portable; it was heavy weighing 7.3 kg (16 lb) and extremely expensive. It was not met with great success and was discontinued only two years later.
• In 1990, Intel introduced the Touchstone Delta supercomputer, which had 512 microprocessors. This technological advancement was very significant as it was used as a model for some of the fastest multi-processors systems in the world.