Microcode, which is a no-go for modern designs

[Jeffrey S. Worley]

On Sat, 2019-01-05 at 12:00 -0600, cctalk-request at classiccmp.org wrote:
> Re: Microcode, which is a no-go for modern designs

I was a tech in the 90's when the original Pentium FDIV bug was
storming.  The issue was confined to the integrated floating point
portion of the processor and was therefore rarely an issue as the vast
majority of software did not use the mathco portion of the chip.  Only
a handful of applications and relative handful of users were affected. 
This became Intel's position on the matter and they hoped the issue
would just die down to those handful whom they would provide new chips.

The issue did not die down and the bad press forced the decision to
replace ALL pentiums affected.  Only a relative few were actually
replaced in the home and small business arena.  A software patch was a
common solution to the problem.  It masssaged input to the FDIV
instruction to produce a corrected result and worked pretty well as I
recall.

At the time of the storm, the Pentium was still pretty new and very
expensive.  Most folks were getting along with AMD k5 and k6
processors.  I WAS.  I went from k6 to Celeron.

Best

Jeff