Path: utzoo!attcan!uunet!seismo!sundc!pitstop!sun!decwrl!labrea!rutgers!mailrus!ncar!tank!uxc!uxc.cso.uiuc.edu!kailand!pwolfe
From: pwolfe@kailand.KAI.COM
Newsgroups: comp.sys.sequent
Subject: Re: Third Party Disc Experience on Sequ
Message-ID: <2400024@kailand>
Date: 4 Oct 88 14:19:00 GMT
References: <1049@orion.cf.uci.edu>
Lines: 28
Nf-ID: #R:orion.cf.uci.edu:1049:kailand:2400024:000:1401
Nf-From: kailand.KAI.COM!pwolfe    Oct  4 09:19:00 1988


/* Written  1:01 pm  Oct  3, 1988 by peter@clsib21.UUCP in kailand:comp.sys.sequent */
>
> BUT!!!!  The DCC is a VERY intelligent controller.  So intelligent, you have
> to be intimately familiar with it and the drive to get the timing right.
>
> We had to take a three-day course from Sequent to figure this whole thing
> out.  Let's just say that adding drives is a non-trivial project.
>
> Of course, theoretically, you could add any SMD-interface drive to the DCC
> if you had enough information.

Adding disk drives is ONLY non-trivial if you try to add drives that Sequent
doesn't already support.  A quick peek into /etc/disktab shows which drives
they currently support on the DCC:  Fuji M2333K, M2351A (eagle), M2344K,
M2382K, CDC 9715-340, and 9771-800.  Adding those drives is relatively
trivial, compared to adding unsupported drives.

One problem (detailed in a talk given by Purdue University at the 1987
Sequent User's Group meeting) is that the disk format programs Sequent
delivers has the drive parameters hard coded in, instead of reading them from
a user-editable table.  So even if you know all the information that the format
program needs, you need the *source* code to be able to add drives.  This
eliminated any chance we had for adding non-supported drives.

Patrick Wolfe
System Manager, Kuck and Associates, Inc.
Patrick.Wolfe@kailand.kai.com  -or-  kailand!Patrick.Wolfe