Intel 8080 processors
Introduction: April 1974
The next chip in the lineup was the 8080, introduced in April 1974, running at a clock rate of 2MHz. Due mostly to the faster clock rate, the 8080 processor had 10 times the performance of the 8008. The 8080 chip contained 6,000 transistors and was built on a 6 micron process. Like the previous chip, the 8080 had an 8-bit data bus, so it could transfer 8 bits of data at a time. The 8080 could address up to 64KB of memory, significantly more than the previous chip. It was the 8080 that helped start the PC revolution, as this was the processor chip used in what is generally regarded as the first personal computer, the Altair 8800. The CP/M (Control Program for Microprocessors) operating system was written for the 8080 chip, and Microsoft was founded and delivered its first product: Microsoft BASIC for the Altair. These initial tools provided the foundation for a revolution in software because thousands of programs were written to run on this platform.
Source: Upgrading and Repairing PCs (13th Edition) by Scott Mueller.