Floating Point Unit. The thing that does mathematical operations on floating point numbers. It used come separately from the CPU as an add-on chip, but around the 486 era, manufacturers started integrating it on the same die as the CPU. Of course, as these things go, from the system programmers point of view, there is still no difference between an add-on FPU and an integrated one.

The one pictured here is an add-on FPU for an Intel 80386 CPU.

[–] pineapplelover@lemm.ee 10 points 7 months ago (2 children)

Thank you. Didn't know that was a thing. I never had to buy an fpu so it was just built with the cpu so I never learned what it was.

[–] Appoxo@lemmy.dbzer0.com 6 points 7 months ago* (last edited 7 months ago) (2 children)

What you can by is a ~~FPGU~~ FPGA :)
Basically a lego kit for a CPU you can program for different use cases which dont warrant cpu manufacturing at scale or prototyping

[–] Davel23@fedia.io 12 points 7 months ago (1 children)

FPGA, but close enough.

[–] Appoxo@lemmy.dbzer0.com 4 points 7 months ago

[–] xthexder@l.sw0.com 2 points 7 months ago* (last edited 7 months ago)

Now I really want a lego kit of a mechanical computer. That would be so cool.

[–] mindbleach@sh.itjust.works 2 points 7 months ago

It got swallowed by CPUs pretty quickly. On 386 it was a real coprocessor: the 387. On 486 it was a whole CPU that disabled the first CPU. The 487 was just a 486 with floating-point built-in.

But it still checked that you had a genuine Intel 486 installed, or it wouldn't run. Because money.