Date: Fri, 5 Feb 93 12:52:29 EST
From: DJ Delorie <dj AT ctron DOT ctron DOT com>
To: IMHW400 AT indyvax DOT iupui DOT edu
Cc: djgpp AT sun DOT soe DOT clarkson DOT edu
Subject: Help on 80387 emulator

>>A 486 without a FPU?  Sounds broken to me.

>I just went through this little shock on another list.  Here's what I'm told:

>o	A 486 DX is a complete chip.

>o	A 486 SX is a complete chip but with the FPU "disabled".  I suppose
>	that they just erased a couple of critical traces on one of the masks.
>	Unlike the 386 SX, it has full-width external address and data buses.

>o	A 487 "coprocessor" is a 486 DX that knows how to disable your 486 SX
>	completely and take over its work.

>It sounds just crazy enough to be true.

I'm well aware of all this, and it IS true.  It STILL sounds broken to
me, even if that's what Intel intended.