IDE-Qbus/Unibus was:Re: Old IDE hard drives

From: Christian Fandt <>
Date: Tue Jan 13 21:22:41 2004

Although certain series of IDE drives from the manufacturers which Joe had
listed occasionally have reliability issues, I think small drives like
these are fine for use in PDP-11 machines, for example. I intend to bring
up and run my PDP-11/34A plus one or two small 11/23 or 11/73 machines with
modern hard drives and CDROMs. The 11/34A has a pair of RL02s with it, but
they are somewhat lacking in easy-to-find blank media and capacity. 211BSD
intrigues me to use on the 11/34A but I think the size is too large for an
RL02. If I have an installable copy of RT-11 v4.x in a pile of RX50s and/or
RX01/02s on hand, that would be a possibility too.

IDE or SCSI are the choices we have with IDE drives being frequently
available. However there is no clear solution (that I've seen) as to an ATA
interface to either Qbus or Unibus.

SCSI, on the other hand as discussion here has shown, presents a more
practical mass storage system because there are plentiful reasonably priced
small-sized SCSI drives out there and even drive interface cards to be
found, albeit the cards are relatively expensive and somewhat hard to find.

In addition to my PDP machines, I have a VAX-11/730 I want to get running
but it came without any mass storage system. Yeah, I know it is slower than
molasses in January (in the Northern Hemisphere ;-), but it is an early
type big iron VAX and somewhat manageable as to physical size in this house
-which is an important criteria. Ideal situation would be for me to install
a Unibus SCSI controller and a SCSI HDD and CDROM into the 730. Lots of
room. OpenVMS 7.2 is noted as working on the 11/730 (but not the 11/725).
But I have a VMS v5.4 Grey Wall, so a version around that range would be
probably just fine if I can find a distro on the proper media and buy a
Hobbyist license. I also have an MVII which should get a drive retrofit of
some sort.
To that end, given that there were two known homebrew IDE/ATA adapters (one
from Ukraine; other shown at: ), I want
to know everybody's opinion of these?

I know sometime late last year there was some discussion of IDE on the DEC
busses and I think the question was raised as to whether either worked and
how well. The question did not get completely answered from what I can
find. In fact, the ATA adapter has not shown any development
progress since April 2002, so it may be a non-starter.

What has anybody else done toward getting an IDE/ATA adapter of some sort
built and stuffed into their Qbus or Unibus machine(s)?




Upon the date 07:41 AM 1/13/04 -0500, Joe Stevenson said something like:
>Is there any interest in older IDE hard drives, 170-540MB?
>I listed them on eBay, but got no response. I probably should have posted
>them to the list, but I wasn't sure that was allowed, so I didn't.
>If there is any interest, I will relist them. If it does not violate the
>rules, I will provide links to them.
>Here is a list of what I have:
>Maxtor 7540AV 540 MB IDE Hard Drive
>Seagate 1.0 GB IDE Hard Drive
>Western Digital Caviar 212 MB IDE Hard Drive
>Western Digital Caviar 256 MB IDE Hard Drive
>ELS127 Quantum 127 MB IDE Hard Drive
>ELS170 Quantum 170 MB IDE Hard Drive

Christian Fandt, Electronic/Electrical Historian
Jamestown, NY USA
         Member of Antique Wireless Association
Received on Tue Jan 13 2004 - 21:22:41 GMT

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