PDP 11/23 PLUS system for sale

Paul Koning pkoning at equallogic.com
Wed Jun 15 13:28:02 CDT 2005


>>>>> "Allison" == Allison  <ajp166 at bellatlantic.net> writes:

 Allison> Actually depending on OS and general usage the critical
 Allison> factor for the DEQNA was not rev but, is it functional at
 Allison> all?  Most of the DEQNAs I've touched and used either worked
 Allison> or were dead, rev was a minor issue save for certain OS
 Allison> support issues.  One of the REV issues was that the more
 Allison> reworked versions tended to have more failures (IE plain old
 Allison> dead) resulting from greater amounts of handeling and
 Allison> use/abuse.  For Q-bus 11s the DEQNA was an acceptable
 Allison> device. 

>From what I remember (very blurry now) DEQNAs were known to corrupt
data.  That was very obvious on VAXclusters, which is why VMS
eventually took them off the supported device list permanently.  But
it's an issue for any application (except, *maybe*, when running TCP
since the TCP layer checksum may help -- or may not, it's not that
strong...).  That applies just as much for PDP11s.

	paul




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