AMD was founded in 1969 and was specialized in the design and manufacturing of micro chips. First logic chips, later RAM and eventually it entered the CPU business. They cloned the 8080 designed by Intel and also designed a RISC based CPU themselves.
In 1982 Intel licensed AMD to become a second source manufacturer for the 8086 and 8088 CPU. Later, Intel also licensed the 80286 to AMD but all licensing ended in 1986 when Intel canceled the contracts with AMD. By this time the 80386 was released and AMD wasn’t going to leave the x86 business just like that. A series of fierce court battles followed and the fight in the courtroom still goes on.
The AMD 80C287 was introduced in 1990 and was a reverse engineered part from the original Intel 287 Math Coprocessor. AMD hadn’t designed the FPU themselves but asked Micro Integration Corp. (MIC) to design the 287 for AMD. The following years AMD’s 287 was subject of several court litigation. The last litigation ended in 1994, when the jury ruled that AMD had the right to copy the Intel 287 microcode.
The 80C287 was AMD’s only math coprocessor for the x86 business. There are some references that AMD and ULSI Systems were close to singing a pact where ULSI would provide its 83C87 to AMD. This deal was never finalized, probably because of the aggressive attack of Intel on ULSI. Intel filed a criminal and a patent infringement suite against ULSI Systems in 1990.