Intel is the inventor of the 8080 CPU that started the PC business. PC is short for Personal Computer and that’s exactly what Intel created. A computer just for you, instead of a large mainframe in the basement of a company that did the computing for a whole lot of people.
With the IBM PC the world of the PC really was accessible for everyone, provided you could pay for one. It cost around $1500 at the time, which would be almost $5000 today.
The IBM PC was equipped with a 8086 micro processor which did all the calculating. With the ever growing possibilities of the software on the PC so did the need for speed. Some software was extremely demanding on the CPU, for instance database and CAD programs. The need for some sort of accelerator for these types of application was born. A number crunching device that could execute certain types of instructions very fast to relief the CPU.
That was how the idea for a Math coprocessor was born. Intel recognized the need and the commercial possibilities and got to work. They created the 8087, a processor that was specialized in Floating point instructions. It operated in together with the CPU and executed only the Floating point instructions. The 8087 was a specialized processor that helped the main processor, it was a coprocessor!
The 8087 Math coprocessor was designed for use with the 8086 and 8088 CPU. It could also be used with the 80186 but not with the 80188. When the 80286 was released in 1982, Intel also designed a coprocessor for that CPU. The 80287 was released in 1983. The PC business was growing fast, in fact the business was large enough for more companies to make money from math coprocessors.
Companies like Cyrix, IIT and AMD created Intel compatible coprocessors. Intel, without much effect, tried to keep the new competitors out of the market by sueing them for patent infringement.
Intel released the 80386 in 1985 And the 387 coprocessor came to marked one year later in 1986. For the 386 even more companies released compatible coprocessors, Weitek, ULSI and Chips&Technologies.
Math coprocessors had always been separate chips and this was for a reason. The semiconductor manufacturing techniques at the time were not advanced enough to integrate the coprocessor and the CPU on one core. The defect rates would have been too high. That was why the coprocessor was a separate chip.
However, things changed with the introduction of the 80486. Manufacturing techniques had advanced considerably since the 8087 days and Intel had integrated the Floating point processor with the CPU in one package.
That move effectively killed the coprocessor business. Although the 386 platform was very popular sales continued to decline. By the year 1995 most manufactures of math coprocessors had moved on either to create Intel compatible CPU’s or leave the x86 CPU arena to design other products.