gryffinwings wrote on 2024-07-19, 01:00:

I am trying to figure out what I need to add an FPU to my old Packard-Bell Legend I. It has an AMD 286 at 12 MHz; I understand that I need something that is at least 2/3 the speed, so a 10 MHz 287 would work. However, I hear I can use a 287XL, but I'm not sure, can someone add some clarity to this so I can understand. Can I use either one?

80287 XL questions

Isn't the 80287XL better than a plain 287 in just about every possible way? Although they're rated as 12.5MHz parts (mostly because intel didn't make 286s faster than 12.5MHz), they've been proven to work pretty well north of 25MHz. So the 80287XL should work in pretty much any 286 board.