[GTALUG] Skylake bug

[James Knott]

On 01/12/2016 12:11 PM, Lennart Sorensen wrote:
> On Tue, Jan 12, 2016 at 09:41:11AM -0500, D. Hugh Redelmeier wrote:
>> > <http://arstechnica.com/gadgets/2016/01/intel-skylake-bug-causes-pcs-to-freeze-during-complex-workloads/>
>> > Skylake CPUs can hang during certain computations.  Prime searching folks 
>> > found this.
>> > 
>> > Interesting that Intel says that new firmware can fix it.
> Firmware updates have been available for all intel CPUs since the
> Pentium Pro.  I think they learned the hard way on the Pentium which
> did not have that feature and needed it.
>

Many years ago, I worked as a computer tech, maintaining various models
of minicomputer.  One thing some computers had then was accessable
microcode.  With the Data General Eclipse line, the microcode was stored
in ROM, but if the Writable Control Store (WCS) option was installed,
you could add new or even modify existing instructions.  The DEC VAX
11/780 loaded it's microcode from a floppy at every boot, so it was a
simple matter to provide an updated version.

It was "fun" trouble shooting a problem by stepping through the
microcode.  ;-)