Bob,

Good to hear you again.  How are your critters?
Congrats on the good luck!  Your guess about 
the boards is right, they are just different
versions of the same board.  I think it was 
first made by Webster, which was then bought
out by Sigma.  Anyway, I have a photocopy of 
the manual for that board, and it's in 10 
chapters.  If you search the list archives,
there's also a thread or two about it.

The board is most likely already set up to 
go, but you need to run some software to 
get it to talk to your drives. 

First, check to see if it is set up to be
the first disk controller.  On my board
there is a set of switches labeled SW2,
but I think it is also known as N6, from 
the manual.  There should be 10 switches
on this set, the top 6 are mutually 
exclusive.  If 10 is pushed up, you are 
at the CSR for the first disk controller
(772150), if 9 is pushed up, you are 
the second controller (760334), etc.
Switch 4 is unused, and the bottom 3 switches
control the onboard bootstrap.  I think this
is only relevant for PDP11.  On my board, 
switch 3 is pushed up, which means onboard
boot disabled.  If you hold the board with 
the backplane side down, there is another 
small box of 4 switches above and to the right.
All 4 of these should be pushed to on. 
Below and to the right is another box of 
4 switches, all on except for the 4th.

The ESDI drives use the same cabling
as MFM, but can take up to 4 drives 
on a chain.  There are 3 of the 
20 pin controller connectors at the 
edge of the board, and one inside.
There is also one 34 pin data connector.
Run 1 20-pin cable to the 20-pin connector
on each drive.  Run the data cable to 
each drive in series.  

The two important things to remember
are that:

1. Each drive must be set to a 
unique ID of 1,2,3 or 4.

2. The last drive in the chain 
must be terminated.

Now, with the Maxtor drive that 
you have, the drive number jumpers
are in a block of 8 near the connector
end of the drive.  The very top jumper
sets it to drive 1, the next to 2, 
and so on.  (There are 8 because the 
designers of ESDI originally 
envisioned 8 possible drives on 
a controller, but it never came to 
pass, I believe.)  The terminator is 
a little yellow ceramic thingy up 
there near that jumper block.  When
it is plugged in, the drive is terminated.
If you have two of these drives, you should
easily be able to see which one was terminated
and which one wasn't. 


Now, the magic incantation (from
the >>> prompt):

D/P/W 20001F40 20
D/L   20088008 80000002
D/W   W0001468 AC
S 400

This should startup up 'WOMBAT', the 
program you need to use to talk to your
drives.  Since this mail is now long enough,
I won't go into details.  It's possible 
somebody has scanned that manual into PDF
by now and put it up on the web somewhere,
but I haven't found it.  Anyway, this 
controller is really neat.  It also has
a connector that you can hook up a terminal
to, and it also allows you to boot a PDP-11
if you don't have a DLV-11 handy.

Hope this helps!

Doug



On Mon, 13 May 2002 NA4G@aol.com wrote:

> I have been away from the vax list for half a
> year or so, having retired from Moo U, but,
> after running across a tired ol' MVII critter
> in a BA123 cabinet, the urge to roll a VAX back
> to life just couldn't be resisted.....(:+}}...
> 
> Anyway, I found two 4 drive esdi boards, almost
> identical, one labelled SCD-RQD11/EC and the
> other WQESD/4.  There are 3 jumper blocks on
> them, and I am wondering how the switches should
> be set.  The configuration I want is a tape
> drive and 4 esdi drives, which will push the
> BA123 fairly close to its limits.  The address
> switches at N6 on the boards are set identically
> but the small 4 block switches at W2 and X8 are
> set differently.  Any pointers as to how they
> should be set for all 4 esdi drives, are muchly
> appreciated.
> 
> Any leads on docs for these boards would be
> appreciated, too.
> 
> Thanks
> 
> Bob Keys/NA4G@aol.com
> 
> (There is something fun in finding a 1 buck VAX
>  and bringing it back to life.....(:+}}...)
>