The first impulse in short history of processors was in year 1947, when the transistor was discovered in Bell's Laboratories, this was smaller and more effective than valves used before. The second impulse was the work of engineers in Texas instruments, which were able to get more transistors on one substrat in year 1959, they linked them with bridges and thus created the first integrated circuit on the world. This was a great change in electronic industry - there were first time small curcuits executing fixed given operations. This discovery caused the born of calculators, which we now take for a common helpmate.

    In year 1969 a young American company named Intel got a good order from a Japanese calculator manufacturer to design integrated circuits for their new products. But the whole design was so complicated that Intel chose another way - they developed a universal circuit handling functions dependent on a programm in computer memory - the first processor named 4004 was born. It's whole architecture was four bit (good for handling of decimal numbers) and was running on a frequency of 60 kHz. This little woder topic number one for many engineers and theoreticians which dreamed of a computer - inteligent terminal serving the whole society.

    But processor 4004 was too slow so Intel developed 8008 and 8080, respectively. Their architecture was eight bit. Another two circumstances influenced the development of "eightbits": In year 1976 created a young company named Zilog (it's boss Frederico Fagin, main developer of 8080 processor, left Intel two years before) processor Z80, with it's performance (4 MHz) and construction (first processor which had no need for auxiliary circuits and supported dynamic memories, which were ten times cheaper) was it "king of the hill" for many years (it's the kernel of possibly the most known "eightbit" - ZX Spectrum). But a year before a company named MOS Technology presented it's processor 6502 (1,79 MHz, the heart of well known Atari). It's plus wasn't in it's performance but in it's price - it cost only 30 $. So that's why its rivals dropped prices of their processors from approximately 200 $ to approximately 60 $ in some days.