CDC Wren-v for DS3100

[Matthias Kandler]

I recently installed a ds3100 with a WREN V disk. So I'll report my
experiences.

It's not easy to get the right cables to connect the disk to the ds3100.
So far we are only able to connect the disk via the TK50. But we 
heard a rumour that DEC sells the right cables. (Our DEC-rep didn't
say a word about that. See last 2 lines of this article :-)

The Ultrix installation tape does not support third party disks. But this
can't stop us. There are ways out:

	   Choose 'System Management' on the first prompt of the installation
	   procedure. Then 'ed install.1'. After the lines

		RZ55)
			ns=36;nt=15;;
	   add the lines

		UNKNOWN)
			ns=48;nt=15;root_D=WREN;;	.

	   Partition the disk as you need it.  

		     cd /dev; MAKEDEV rz0
	      [e.g.] chpt -pa 0 32768 -pb 32768 32768 /dev/rrz0c
 		     chpt -pd 65536 32768 -pg 98304 1075626 /dev/rrz0c 
	
	   Then do 'cd /;. .profile'. This restarts the installation.
	   Choose 'Advanced installation' now.

	   In the second phase of the installation (after booting from disk)
	   you have to stop the installation by ^c. Then 'ed /etc/disktab'.
	   Add an entry like

	WREN|UNKNOWN|CDC WREN V 94181-702 (unknown by DEC finder):\
        :ty=winchester:ns#48:nt#15:nc#1543:\
        pa#32768:ba#8192:fa#1024:\
		.
		.	[ Partitioning information is irrelevant]


	  Then 'cd /; . .profile'

I built a customized installation TK50 that does the above. If you want to
know how to do this send me mail. I'm now in the process to setup a
'Remote Installation Service' from a VAX for the ds3100.

The right way to solve the 'UNKNOWN problem' above would be to teach finder
(and also autoconf) to recognize the CDC WREN V. We didn't get Ultrix 3.1
sources yet. So I could not try it.

The ds3100,WREN V configuration is running fine now for ca. four weeks.
~~
Matthias Kandler  Inst. f. Informatik     LOC=lan.informatik.tu-muenchen.dbp.de
                  TU Muenchen             kandler at LOC
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