Intel '8087'
The 8087 can be paired up with an 8086 or 8088. It's able to do floating point calculations much faster than the normal processor.
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The first x86 16-bits co-processor (FPU; floating point unit) which can work with both the 8086 and 8088. Back in the old days the normal processors didn't have a co-processor for floating point calculations. You didn't really need one and if you did as specialized CAD/CAM or mathematics user you could upgrade your system with an FPU. Both the 286 and 386SX and 386DX didn't have a co-processor. It was not until the 486DX before processors had FPU's integrated.
The 8087 has 45,000 transistors which is a lot more than the 29,000 of the 8086. > Read more