Hardware Reference
In-Depth Information
Chapter 3. Processor Types and Specifications
Microprocessor History
The brain or engine of the PC is the processor—sometimes called
microprocessor
or
cent-
ral processing unit
(CPU).TheCPUperformsthesystem'scalculatingandprocessing.The
processor is one of the two most expensive components in the system (the other being the
video card). In higher-end systems, the processor can cost up to four or more times more
than the motherboard it plugs into. Intel is generally credited with creating the first mi-
croprocessor in 1971 with the introduction of a chip called the 4004. Today Intel still has
control over the processor market, at least for PC systems, although AMD has garnered a
respectable market share. For the most part, PC-compatible systems use either Intel pro-
cessors or Intel-compatible processors from AMD.
It is interesting to note that the microprocessor had existed for only 10 years prior to the
creation of the PC! Intel released the first microprocessor in 1971; IBM created the PC in
1981.Nearlythreedecadeslater,wearestillusingsystemsbasedmoreorlessonthedesign
of that first PC. The processors powering our PCs today are still backward compatible in
many ways with the Intel 8088 that IBM selected for the first PC in 1981.
The First Microprocessor
Intel was founded on July 18, 1968 (as N M Electronics) by two ex-Fairchild engineers,
Robert Noyce and Gordon Moore. Almost immediately, they changed the company name
to Intel and were joined by cofounder Andrew Grove. They had a specific goal: to make
semiconductor memory practical and affordable. This was not a given at the time, consid-
ering that silicon chip-based memory was at least 100 times more expensive than the mag-
netic core memory commonly used in those days. At the time, semiconductor memory was
going for about a dollar a bit, whereas core memory was about a penny a bit. Noyce said,
“All we had to do was reduce the cost by a factor of a hundred, then we'd have the market;
and that's basically what we did.”
By1970,Intelwasknownasasuccessful memorychipcompany,havingintroduced a1Kb
memory chip, much larger than anything else available at the time. (1Kb equals 1,024 bits,
and a byte equals 8 bits. This chip, therefore, stored only 128 bytes—not much by today's
standards.) Known as the 1103 dynamic random access memory (DRAM), it became the
world'slargest-sellingsemiconductordevicebytheendofthefollowingyear.Bythistime,
Intel had also grown from the core founders and a handful of others to more than 100 em-
ployees.
