[HECnet] Drives for a VAX-11/730

[Johnny Billquist]

On 2013-07-15 16:37, Clem Cole wrote:
Unibus to SCSI is probably your best bet.

http://bitsavers.trailing-edge.com/pdf/cmd/CDU-720_May92.pdf

These are available on eBay for about a $1K last I looked.     You'll need
to poke around the VMS web sites for the drivers, but we had some of
these on a couple Unibus machines, including a 780 a >>long<< time ago.
    I know no reason why it would work for a 730 - although you might
need to sysgen on a working system to create the boot disk.

Something like a CDU-720 will work just fine. Normal MSCP, so no special device drivers needed either. Works fine in an 11/730, or any Unibus machine in fact. Bootable on just about anything as well.

	Johnny





On Mon, Jul 15, 2013 at 10:21 AM, Bob Armstrong <bob at jfcl.com
<mailto:bob at jfcl.com>> wrote:

            My 11/730 is not happy     the electronics work great and are even
      fairly easy to fix, but keeping disk drives on the thing working is
      proving to be a challenge.   Right now it has two RA81s and one has
      quit completely (   servo fine position error   ) and the other is
      flaky.   The original R80 on the RB730 had the HDA die years ago and
      I   ve never been able to find a replacement.____

      __ __

            I have several vintage SMD drives, including a couple of nice CDC
      9715 drives, that I was thinking about using to replace the RA8x
      drives.   I have not one but two UNIBUS SMD controllers     an Emulex
      SC21 and a Spectra Logic 121     that I thought would do the job, but
      after reading the fine print yesterday that turns out not to be
      true.   Both controllers emulate RH11s with RM0x drives attached,
      which is fine if you   re a PDP-11 but VMS has never supported that
      configuration.____

      __ __

            [Before anybody says    Wait     RM05s are supported by VMS,    that   s
      only partly true.   VMS supported MASSBUS disks on a RH750 or RH780
      controller, but VMS has never supported the RH11.   Emulex actually
      sold a special VMS driver for their card, but I don   t have it and
      besides, VMB still wouldn   t support it.   The Spectra Logic manual
      only talks about PDP-11 OSes and carefully avoids ever mentioning
      VMS.]____

      __ __

            I   ve got some RA7x drives, but there   s no easy way to mount them
      or supply power to them.   I   m not sure if there ever was a rack
      mount chassis for RA7x drives.   There was for RA9x drives, but those
      I don   t have.     I also have two RC25 drives and several AZTEC
      controllers, but those drives were horribly unreliable even when
      they were new.   Neither works, and fixing them or getting removable
      media for them is hopeless.____

      __ __

            Does anybody have any other ideas?   Who else has an old UNIBUS
      VAX?   What are you doing to disk drives? ____

      __ __

            I   ve actually had the 11/730 for about fifteen years now     I
      restored it out of parts from two different 730s that were
      scrapped.   It   s been fairly easy to keep running except for the
      drives, and although it   s admittedly a bit slow, it   s a cool
      machine.____

      __ __

      Bob____