From: knight@hal.gnu.ai.mit.edu (Knight of Tossing and Turning) Subject: AMD-40 Cycle Timing Problems Date: Sat, 15 Aug 1992 23:05:11 GMT
Sorry this took forever to jump into this conversation but I figured it
wasn't going to freak so many people out.
I was instructed in my PC Archetecture class that the AMD-40 CPU (and
only that CPU) has a relatively minor problem with timing between
certain cycles. I'm not sure which combination of instructions causes
the problem, and I'm not in a position to find out.
If someone looks this up, it is a documented bug. However, I don't
have the AMD CPU manuals to look it up.
The reason this is only for the 386-40 is because it is basically a
superscaler CPU (like a 486-2DX50) consisting of something like
2-25 MHz chips. I'm not really into the hardware aspect of personal
computers, so don't ask me much more than this. But is basically
timing between the two where the bug occurs.
As the guy with the flat-hat says, "A PC that is MS-DOS compatible
might not be UNIX compatible, but any that is compatible with UNIX
will run probably anything."
--- Eric Knight