[pups] What hard drives to look for for PDP-11 use?

Steven M. Schultz sms at moe.2bsd.com
Thu Oct 12 13:07:14 AEST 2000

Hi Bob -

> From: rdkeys at unity.ncsu.edu
> Steven.... I have been thinking of trying to find a PDP-11 of some sort
> (like hunting for needles in a hay stack in this part of the woods, but

	Interesting.   I wouldn't have thought an 11/73 or similar would
	be too hard to find.

> 1.  What mfm hard drives from the non-DEC world could be adapted to
>     work on a PDP-11?

	Tim has already jumped in with a pointer or two.

> 2.  Can any scsi drives be used (RZ-23's or that kind of thing?).

	Oh yes!   But you need to have a Qbus SCSI<->MSCP controller.  They
	are easy to _find_ but quite *expensive*.   Not as expensive as
	they were when I shelled out US$1500 for a new Emulex UC08 (and that
	with a good discount - the sales person was sympathetic to my
	explanation this was for a 'hobby').    Used CMD, Emulex or Dilog
	controllers will run around $500-900.

	Once you have gotten over the sticker/exchequer shock the upside
	is that you can use about many SCSI disk or tape drives that other
	folks are tossing otu because they're too small.   The older ~300MB
	and 1GB disks that are not useful on modern systems are great in
	a PDP-11 environment.    Uh, don't bother putting a 73GB Cheetah
	on an 11 ;)

	One place that lists CMD and Emulex controllers is:


> I will assume the target OS is 2.11BSD or 2.9BSD, since those seem
> to handle the greatest assortment of hardware types.
> Can any of these non-DEC drives be adapted to MVII use?

	At one time I had a uVax-II with a Dilog DQ696 (I think that was 
	the model number) that had a couple ESDI drives on it - a ~300MB
	Miniscribe disk and a couple Maxtor RD53 sized drives.

> Can any of the early MFM or ESDI Sun drives be used?

	Definitely.    Emulex QD33 and QD35 adaptors (in addition to the
	Dilog DQ696) ring a bell as far as non-SCSI disks go.

	Steven Schultz
	sms at moe.2bsd.com

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