# Intel 8087

> floating-point unit for the Intel 8086 series of microprocessors

**Wikidata**: [Q1632017](https://www.wikidata.org/wiki/Q1632017)  
**Wikipedia**: [English](https://en.wikipedia.org/wiki/Intel_8087)  
**Source**: https://4ort.xyz/entity/intel-8087

## Summary
The Intel 8087 is a floating-point unit (FPU) coprocessor designed to accelerate mathematical calculations for the Intel 8086 and 8088 microprocessors. Released in 1980, it provided hardware support for floating-point arithmetic operations that were previously handled in software. The 8087 significantly improved the performance of scientific and engineering applications running on early IBM PC-compatible computers.

## Key Facts
- Released in 1980 as a coprocessor for Intel 8086/8088 microprocessors
- Provides hardware acceleration for floating-point arithmetic operations
- Uses x87 instruction set architecture
- Manufactured by Intel Corporation
- Also known by aliases "8087" and "X87"
- Has a sitelink count of 20 across various language Wikipedias
- Classified as a floating-point unit (FPU)
- Developer and manufacturer is Intel Corporation
- Has a GND ID of 4129509-2
- Listed in Library of Congress authority file with ID sh85067151

## FAQs
### Q: What is the Intel 8087 used for?
A: The Intel 8087 is a floating-point unit coprocessor that accelerates mathematical calculations for Intel 8086 and 8088 microprocessors. It handles complex floating-point arithmetic operations like addition, subtraction, multiplication, and division, significantly improving performance for scientific, engineering, and mathematical applications.

### Q: When was the Intel 8087 released?
A: The Intel 8087 was released in 1980. It was designed to work alongside Intel's 8086 and 8088 microprocessors, providing hardware support for floating-point operations that would otherwise need to be performed in software.

### Q: What makes the Intel 8087 different from the main processor?
A: The Intel 8087 is a coprocessor that specializes in floating-point arithmetic operations, while the main processor (8086/8088) handles general computing tasks. The 8087 offloads complex mathematical calculations from the main CPU, dramatically improving performance for applications that require extensive floating-point computations.

## Why It Matters
The Intel 8087 represents a pivotal advancement in personal computer architecture by introducing hardware-level floating-point computation capabilities. Before its introduction, floating-point operations were performed through software libraries, which were significantly slower and limited the practical applications of early personal computers. The 8087 enabled personal computers to handle complex scientific calculations, engineering simulations, and mathematical modeling tasks that were previously only possible on mainframe computers. This coprocessor effectively democratized high-performance computing, allowing small businesses, researchers, and engineers to perform sophisticated calculations on desktop machines. The 8087's architecture also established the x87 instruction set that would influence Intel's floating-point design for decades to come, making it a foundational component in the evolution of personal computing and numerical computation.

## Notable For
- First floating-point coprocessor for the x86 architecture, establishing the x87 instruction set standard
- Dramatically improved performance for scientific and engineering applications on early personal computers
- Enabled complex mathematical operations that were previously only possible on mainframe computers
- Created the foundation for Intel's floating-point architecture that influenced designs for decades
- Essential component for early IBM PC-compatible computers running CAD, spreadsheet, and scientific software

## Body
### Technical Architecture
The Intel 8087 operates as a coprocessor that works in conjunction with Intel 8086 or 8088 microprocessors. It communicates with the main CPU through dedicated coprocessor interface signals and shares the same memory space. The 8087 contains an 80-bit wide arithmetic logic unit capable of performing operations on 32-bit, 64-bit, and 80-bit floating-point numbers.

### Instruction Set
The 8087 implements the x87 instruction set, which includes operations for floating-point addition, subtraction, multiplication, division, square root, and transcendental functions like sine, cosine, and logarithm. These instructions are executed in hardware, providing significant performance improvements over software-based floating-point libraries.

### Performance Impact
By offloading floating-point calculations from the main CPU, the 8087 can provide performance improvements of 10x to 100x for mathematical operations, depending on the specific calculation. This made previously impractical applications viable on personal computers, including 3D graphics, statistical analysis, and engineering simulations.

### Physical Characteristics
The 8087 is packaged in a 40-pin DIP (Dual In-line Package) similar to the 8086/8088 processors it accompanies. It requires a clock signal from the main processor and communicates through the same data bus, though it has dedicated control signals for coprocessor operations.

### Software Support
Software must be specifically written to take advantage of the 8087's capabilities. Compilers for languages like FORTRAN, Pascal, and C could generate code that utilized the coprocessor when present, while also providing software floating-point fallback routines for systems without the hardware.

## References

1. Freebase Data Dumps. 2013
2. National Library of Israel Names and Subjects Authority File