On Jun 19, 2012, at 10:52 AM, Dave McGuire wrote: On 06/19/2012 10:27 AM, Johnny Billquist wrote: Found 1 DELQA and 4 DEQNA (condition unknown), and also have 1 broken DELQA I recall that the DELQA is more "modern" and better i some way, are they also more prone to failure? No. From a reliability point of view, I've not heard that either should be better or worse. However, the DEQNA is rather buggy in its general performance. Side-by-side, the DELQA is quite a bit faster than the DEQNA, the DELQA-YA ("Turbo DELQA") even more so. That said, the DELQA has a "DEQNA compatibility mode"...whether that makes it as slow and/or buggy as the DEQNA, I don't know. I don't think so. QNA compatibility mode means it works like a QNA from the driver point of view. That was never the issue with the QNA -- if it had worked according to the specification, it would have been quite a good device. The problem was that it never worked correctly, not even after 12 revisions. Finally when rev L didn't work adequately either, the DEC software teams said enough is enough, we're dumping the QNA. The issues were most obvious on VMS; I'm not sure if they were visible enough on the PDP11 OSs to cause concern. Maybe with LAT, probably not or less so with DECnet. I don't remember the details, other than that Local Area VAXclusters were the ones that tended to run into trouble, since those protocols were particularly unforgiving. paul