Intel 80287: Difference between revisions

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The 80287 was introduced in 1982.
The 80287 was introduced in 1982.


[[Integer arithmetic]] requires much less [[silicon real estate]] to implement than calculations on values that had a [[Fraction (mathematics)|fraction]]al component.  Intel off-loaded the hardware to perform those instructions to a [[co-processor]] -- a [[support chip]] devoted solely to that task.  Computers could be equipped with an 80286, and without an 80287.   
[[Integer arithmetic]] requires much less [[silicon real estate]] to implement than calculations on values that had a [[Fraction (mathematics)|fraction]]al component.<ref name=OlympusMicro387>
{{cite news
| url=http://www.olympusmicro.com/micd/galleries/chips/intel387.html
| title=Intel 387 Math Coprocessor
| publisher=[[Olympus Micro]]
| author=Omar Alvarado, Thomas J. Fellers, Michael W. Davidson
| date=
| accessdate=2008-11-27
| quote=
}} [http://www.webcitation.org/query?url=http%3A%2F%2Fwww.olympusmicro.com%2Fmicd%2Fgalleries%2Fchips%2Fintel387.html&date=2008-11-28 mirror]
</ref>  
Intel off-loaded the hardware to perform those instructions to a [[co-processor]] -- a [[support chip]] devoted solely to that task.  Computers could be equipped with an 80286, and without an 80287.   
If the 80287 were present floating point instructions would be off-loaded and executed relatively quickly, by the 80287.  
If the 80287 were present floating point instructions would be off-loaded and executed relatively quickly, by the 80287.  



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The intel 80287 was a floating point co-processor to intel's 80286 models of single chip computer.[1][2] The 80287 was introduced in 1982.

Integer arithmetic requires much less silicon real estate to implement than calculations on values that had a fractional component.[3] Intel off-loaded the hardware to perform those instructions to a co-processor -- a support chip devoted solely to that task. Computers could be equipped with an 80286, and without an 80287. If the 80287 were present floating point instructions would be off-loaded and executed relatively quickly, by the 80287.

The intel 80287 is reported to use the same execution unit as the intel 8087.[2]

Other chips which were lineal ancestors to the Pentium family of computer chips, the intel 80186 and the intel 80386, had a companion floating point co-processor manufactured to accompany it. Intel was to market an intel 80487. But it was not a separate chip, different from the intel 80486.

References

  1. Advanced Micro promotes its power-saving answers to intel 80287 in the UK, Computer Business Review, 1990-08-22. Retrieved on 2008-11-27. mirror
  2. 2.0 2.1 intel 80287: Technical Specification. Retrieved on 2008-11-27. mirror
  3. Omar Alvarado, Thomas J. Fellers, Michael W. Davidson. Intel 387 Math Coprocessor, Olympus Micro. Retrieved on 2008-11-27. mirror