ENIAC used 18,000 vacuum tubes, about 1,800 square feet of floor space, and consumed about 180,000 watts of electrical power. It had punched card I/O, 1 multiplier, 1 divider/square rooter, and 20 adders using decimal ring counters, which served as adders and also gave as quick - access (.0002 seconds) read - write register storage. The executable instructions making up a program were embodied in the separate "units" of UNIAC, which were plugged together to form a "route" for the flow of information. This unit is a far cry from the desk top I am currently using to complete this report.
Further development on the ENIAC in the 1940's resulted in the Mark 1 for the US Navy. The Mark 1 was able to compute complex tables and used a paper tape to store instructions. Early in 1945, Grace Hopper was completing repairs on the Mark 1 when he noticed a moth in one of the relays that were possibly causing the problem. From this day on, Hopper referred to fixing the system as "debugging". .
Over the next five years the advances in computers was due mostly the government and military. The computer at this time was not a feasible asset to a company or individual due to its extreme size and cost of running.
In 1961 Fairchild Semiconductor introduced the integrated circuit. Within ten years all computers were using these circuits instead of the transistors. Computers that were formally building sized were now room sized. Computers were also considerably more powerful. The following year the "Atlas" become operational, displaying many of the features that make today's systems so powerful including; virtual memory, pipeline instruction, execution, and paging.
In the late 1960's and early 1970 innovations and technology continue to improve the world of computes. The evolution of the computer was reduced size and increased power. By the middle of the 1970's personal computers explode on the American scene. Microsoft, Apple and many smaller PC related companies form and compete against each other on the open market.
