> From daemon Wed May  1 19:47:03 1996
> >From owner-port-vax@NetBSD.ORG  Wed May  1 19:46:56 1996
> From: Ken Wellsch <kcwellsc@math.uwaterloo.ca>
> Subject: Re: RQDX3 jumpers
> To: bketcham@anvilite.murkworks.seattle.wa.us (bketcham)
> Date: Wed, 1 May 1996 12:33:22 -0400 (EDT)
> Cc: byeager@txdirect.net, ragge@ludd.luth.se, port-vax@NetBSD.ORG
> Organization: University of Waterloo, Math Faculty Computing Facility
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> 
> The RQDX3 does have such a jumper requirement - alas I cannot confirm
> the precise requirements as my documentation is far too well packed.
> 
> There are four header pins in the upper left corner as I recall (I think
> W23 jumpers the middle pair) but the bottom line behind the jumper
> arrangement has to do with sending the fourth head select signal (binary
> coding) needed with the 15 heads on an RD54 (i.e. four head select lines
> rather than three that smaller drives with <= 8 heads use).
> 
> I also recall the same piece of paper claiming a minimum rev level on
> the controller EPROMs was necessary for "proper" operation.  I vaguely
> recall the values as in the mid to high 200's as well as the newer 3xx
> range.  (I'm sure there are even higher rev's out there)
> 

Here is a note I grabbed off the Internet about a year ago:

    		READ BEFORE INSTALLING DISK DRIVE	2/89

    			RD54 MAXTOR

    * WARNING: This disk drive has been hardware formatted for an 
    RQDX3.  Do not attempt to format this drive on a MicroVAX using
    the Customer Confidence Diagnostics.  The format is not compatible
    with this drive.  If reformat is absolutely necessary, please
    contact Midwest Systems Technical Support Department first.

    1.	The RQDX3 being used MUST be inspected to determine its
    	version, and the W23 jumper MUST be configured accordingly:
    	(FAILURE TO DO SO MAY DESTROY THE HARDWARE FORMAT.)

    	Version 3 Identification

    	IF:	Location 1: ROM 244E5, or 286E5;
    		Location 2: ROM 243E5, or 285E5
    	THEN:	at W23 jumper between post 1 & 2 only.

    	Version 4 Identification

    	IF:	Location 1: ROM 340E5;
    		Location 2: ROM 339E5
    	THEN:	at W23 jumper between posts 1 & 2, and 3 & 4.

    2.	Depending on the drive version, set the white or blue unit
    	select jumper (located in the rear of the drive on the printed
    	circuit board) between C and 3 or 2 and 3 for drive zero (0).


Dave.