2.11BSD on two RL02 drives? Probably not, but...

Rick Bensene rickb at bensene.com
Thu Aug 3 09:10:46 CDT 2017

Glen S. wrote:

>QBus ESDI controllers are relatively cheap. I have several Emulex QD21, Dilog DQ696, and Sigma SDC-RQD11 QBus ESDI controllers. The >problem I have with them is that I now have more controllers than working ESDI drives. Some of the drives that I had which were >working have died while sitting idle. Guaranteed working ESDI drives don't seem to be cheap anywhere and shipping them isn't cheap >either.

I've found much the same with ESDI drives...they tend to die just sitting, and it's not stiction that seems to be the culprit...they simply quit working.   Not sure why, but at one time I had a stash of 18 ESDI drives of various makes and sizes, and I'm now down to 2 that still work.  The rest all just quit.  When not in use, the drives are stored in anti-static bags with a dessicant bag inside, and then stored in a storage tote lined with anti-static pink poly sheeting.  The totes are stored in an environmentally controlled room.   I don't see any reason why they'd die due to environmental conditions.  Something else has to be going on with them.

>To me it seems a lot more cost effective and less trouble in the long run to pay a little more for something like a CMD CQD-200/220 or >Emulex UC07 SCSI controller. I've somehow managed to acquire a couple dozen or so QBus SCSI controllers of various flavors over the >years.

That said, my PDP 11 is Unibus, and Unibus SCSI controllers are darned expen$ive.

I do have some working Fujitsu SMD drives (now, these drives just keep on running!), and I'd love to find a Unibus SMD controller (preferably Emulex), so that I could run a couple of these drives on the 11.   Anyone out there got one that emulates popular PDP-11 disk drives supported by most of the OS's (RT-11, RSTS, and BSD Unix) that can make a given SMD drive "appear" compatible that the would be willing to part with for a reasonable price?  I've heard that the Emulex UD33 and SC21 are the SMD controllers of choice, but do they do MSCP?   I'd love to head any comments from those "in the know" out there.  Are there other alternatives other than Emulex that may work well also?

Thanks for reading!

Rick Bensene
The Old Calculator Museum
Beavercreek, Oregon

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