Path: utzoo!mnetor!uunet!husc6!mailrus!ames!pasteur!ucbvax!GTRI01.BITNET!MSIEWEKE
From: MSIEWEKE@GTRI01.BITNET (Mike Sieweke)
Newsgroups: comp.os.vms
Subject: re: Two RD52's on a MicroVAX II
Message-ID: <8804091125.AA13545@ucbvax.Berkeley.EDU>
Date: 4 Apr 88 14:09:58 GMT
References: <LEICHTER@Venus.YCC.Yale.Edu>
Sender: daemon@ucbvax.BERKELEY.EDU
Organization: The Internet
Lines: 22

>    We want to add a second RD52 disk to a MicroVAX system with an RQDX2
>    controller and one RD52 fixed disk.
>
Jerry Leichter responds:
>I believe you have to change some jumpers to make this work.  Exactly what you
>have to do depends on the kind of box your MicroVAX is installed in - the
>wiring for BA23's and BA123's is different.

Sorry, Jerry, but this is not true.  At my site, I have taken drives from
BA23's and put them in BA123's and vice versa, with no changes to the
drives or controllers.  The RQDXx controllers detect how many drives
are out there with no jumpers.  However, the interleave is different
for the different controllers.  The RQDX3 uses 1:1; the RQDX2 uses 3:1.
The drive must be re-formatted to go from one controller to another.

This is all true when moving drives between VAXes.  It may not hold true
if the machines are PDP-11's.

Mike Sieweke <msieweke@gtri01>             BitNet
          or <msieweke@gtri01.gatech.edu>  ArpaNet
Georgia Tech Research Institute
Atlanta, Georgia