rewriting legacy OS for new iron

From: Zane H. Healy <>
Date: Tue Sep 14 22:19:16 2004

>In commercial use, when SRC had MicroVAXen, we never lost an RD53 (that
>I know of - they might have had to swap one out when I wasn't working
>there at one point). I have that MicroVAX, and its RD53 is still good.
>OTOH, I do know that others have had problems.

Right, but this was how many years ago? The RD52's and RD54's both
seem to still be fairly good disks, but the RD53's are bad news. I
have heard of people opening them up, removing the rubber and going
back to running with them.

> > As long as you don't mind dealing with the troubles involved in a
> > dual-height /73 CPU, they aren't to hard to come by. Of course if you do
> > get one you'll want a third party disk controller w/bootstrap, and a DLV11J
> > for your console ports. It's a pain, but it works.
>I haven't played with a dual-height /73 - I take it, it's like the dual-height
>KDF-11 (11/23) CPU, nothing but a CPU? (Some of my F-11 boxes have that CPU
>and a BDV11, others have the 11/23+ quad-height CPU).

Yes, it's just a bare CPU board, but more importantly it was fairly
common in OEM setups, and as a result the dual-height boards seem to
be fairly common. The full blown quad-height OTOH, seem to be about
as common as an /83 board.

> > Until I upgraded to a
>> Quad-Height /73 CPU, I kept a Webster ESDI board in the system for the
>> bootstrap even though it didn't have any disks attached and the system disk
>> was on a SCSI controller.
>Ah... interesting solution. These days, of course, it's trivial to keep
>a bootstrap on another machine, talk to the -11 via terminal emulator
>(Kermit...) and force-feed any bootstrap you want over the console line.

Not a good solution for me, I like a VT420 for my console, though I
did use this solution briefly.

> > Let me guess it's out of a DECserver 550, if so it's a /53.
>I got it as a bare board, but that sounds right.

Warning my memory stinks today. Does the board have a faceplate on
it like it was for a BA213 box (S-Box comes to mind, but I can't
remember if that's right)? If so you'll have to remove that before
putting it in a BA123. I've actually got three of the boards,
somewhere (a friend of mine got three DS550's).


| Zane H. Healy                    | UNIX Systems Administrator |
| (primary)    | OpenVMS Enthusiast         |
|                                  | Classic Computer Collector |
|     Empire of the Petal Throne and Traveller Role Playing,    |
|          PDP-10 Emulation and Zane's Computer Museum.         |
|                     |
Received on Tue Sep 14 2004 - 22:19:16 BST

This archive was generated by hypermail 2.3.0 : Fri Oct 10 2014 - 23:37:29 BST