In the Z-80 case, though, the clone had become far more popular than the original. The Z-80 was noted for being an improved and less expensive clone of the Intel 8080 processor, similar to the way companies such as AMD, VIA/Cyrix, IDT, and Rise Technologies have cloned Intel's Pentium processors. Personal computers of that time primarily used the Z-80 by Zilog and the 6502 by MOS Technologies. Although Intel is generally credited with inventing the processor and introducing the first one on the market, by the late 1970s the two most popular processors for personal computers were not from Intel (although one was a clone of an Intel processor). Intel's dominance in the processor market hadn't always been assured. This means that all PC-compatible systems use either Intel processors or Intel-compatible processors from a handful of competitors (such as AMD or VIA/Cyrix). Today Intel still has control over the processor market, at least for PC systems, although over the years AMD has garnered a respectable market share. Intel is generally credited with creating the first microprocessor in 1971 with the introduction of a chip called the 4004. The processor is often the most expensive single component in the system (although graphics card pricing now surpasses it in some cases) in higher-end systems it can cost up to four or more times more than the motherboard it plugs into. The CPU performs the system's calculating and processing. The brain or engine of the PC is the processor (sometimes called microprocessor), or central processing unit (CPU). Learn More Buy Pre-PC Microprocessor History

Upgrading and Repairing PCs, 17th Edition

All generation of microprocessor