On 3 Nov 2006, at 5:30 pm, Steinar H. Gunderson wrote:
On Fri, Nov 03, 2006 at 04:55:04PM +0000, Tim Cutts wrote:The 486 was the first CPU in the X86 family to have an integral FPU.Only the 486DX; the 486SX didn't.
Being thoroughly pedantic, yes it did, but it was disabled in the hardware. When you installed a 487, it disabled your 486SX completely, and you were effectively running with a normal 486. A more interesting question is when Intel finally integrated the 86 and 87 processors; as I understand it, the 486 was effectively just a 386 and 387 in a single package; the regions of silicon were still quite discrete. I'd heard that that situation lasted for some time, but I don't know when they were properly integrated. It's kind of like Intel's new so-called four-core chips, which are basically just two of the current dual-core CPUs in a single package (which has interesting implications for memory contention issues, which led to some interesting discussions at SC06 last month)
(Are we offtopic now? :-) )
Oh yeah! :-) Tim