ABSTRACT
This chapter presents an introduction to mathematical coprocessor hardware in general and in particular to the Intel Floating-point Units: 8087, 80287, 80387, 487 SX, and the math unit of the 486 DX and Pentium. The CPU used in all IBM and IBM-compatible microcomputers manufactured to date is an Intel microprocessor of the 80x86 family. The first microprocessor of this family was the 8086, released in mid-1978. In 1981 IBM made public its first desktop computer, called the IBM Personal Computer, which was equipped with the Intel 8088 CPU, a version of the 8086 chip. The first mathematical coprocessor for the 8086 and 8088, named the 8087, was introduced by Intel in 1980. The original design work was the work of John Palmer and Bruce Ravenel. The math unit processes and stores numerical data encoded in seven data formats. However, all internal calculations are performed in an 80-bit data format that allows representation of 19 significant decimal digits.
