From mboxrd@z Thu Jan  1 00:00:00 1970
From: cdl@mpl.ucsd.edu (Carl Lowenstein)
Date: Fri, 13 Dec 2002 11:33:51 -0800 (PST)
Subject: [TUHS] flaky webster or sigma WQESD4 and RQD11 controllers on KA650???
Message-ID: <200212131933.LAA02973@opihi.ucsd.edu>

> From: msokolov at ivan.Harhan.ORG (Michael Sokolov)
> To: tuhs at tuhs.org
> Subject: Re: [TUHS] flaky webster or sigma WQESD4 and RQD11 controllers on KA650???
> Date: Thu, 12 Dec 02 23:29:58 PST
> 
> Robertdkeys at aol.com wrote:
> 
> > Is there an endemic problem with this style 4
> > port controller running too fast with a KA650
> > compared to a KA630 cpu?
> 
> I have no explanation for your problem, but it has nothing to do
> with speed.  Q-bus is Q-bus, and it follows Q-bus timing, which is
> completely independent of the VAX CPU timing.

Yes but there might be CPU spin-loop timing to run the serial
maintenance port from the ROM bootstrap code of the controller.
Not considered good form -- but such things happen.

Some early version of the Sigma RQD11 would work in an 11/73 but not
a KA630.  I no longer remember the exact symptoms, but I was glad that
at the time Sigma was only an 80-mile drive from here.

    carl
-- 
    carl lowenstein         marine physical lab     u.c. san diego
                                                 clowenst at ucsd.edu