[Info-vax] KZPAC / RAID Array 230 questions

[Alan Frisbie]

On 12/20/20 11:58 AM, Stephen Hoffman wrote:
> On 2020-12-18 01:36:14 +0000, Alan Frisbie said:
> 
>> I recently acquired a DS20 with a KZPAC (RAID Array 230/Plus) SCSI 
>> controller.

> As for the Alpha 21264 processors and processor passes...  IIRC, Alpha 
> EV6 (specifically EV6 and not EV67, etc) 500 MHz pass 2.3 didn't play 
> well with other 500 MHz passes, with a timing bug in the probe 
> instruction implementation that could cause weirdness when used in 
> mixed-pass same-MHz configurations, and mixed EV6 passes are thus best 
> avoided with multi-processor configurations. Mixed-MHz wasn't something 
> you'd want to do.  IIRC, EV68 is all pass 2.6, and all works. And IIRC, 
> there was an FCO for this.

By any chance do you (or anyone else reading this) recall what the story
was with the on-board Adaptec SCSI controller?  The two SCSI connectors
are there, and the early Technical Summary describes them.  However,
the TS says that only Windows NT supports it at first release.  The
Service Manual mentions them but says they are disabled.  Later manuals
don't mention them at all.

I assume that there was some bug, but I'm interested in a bit of detail.
Could they not even be used for the RRD47?  I remember using the one
on the AlphaServer 1000A with no problems, and since the DS20 came out
later I would have expected that the engineers knew how to get it right.

Thanks,
Alan Frisbie