info-vax@ucbvax.ARPA (06/04/85)
From: Gail Rubin <grubin@bbn-spca> ----BEGINNING OF FORWARDED MESSAGES---- Received: from BBN-UNIX.ARPA by BBNJ ; 16 Aug 84 01:32:29 EDT Date: Wed, 15 Aug 84 11:45:40 EDT From: Jon Sutton <jsutton@bbn-unix.ARPA> Subject: LHDH-11 on a VAX 750 To: seventek@lbl-ws.arpa Cc: grubin@bbn-unix.ARPA Your problems sound familiar to me. I installed an LHDH-11 some time back and I remember two problems. First, make sure that the NPR jumper is in the correct state on the slots used for the LHDH and the DZ's in question. Second, the LHDH likes to be the last thing on the bus (ie. as close to the terminator as possible). Also if you have long unibus cabling going through the LHDH make sure that no two cables are the same length and the the total length of the unibus doesn't exceed 50'. When two adjacent cables are the same length reflections on the bus can cause problems. -Jon Sutton ----END OF FORWARDED MESSAGES---- Here is a message that a co-worker of mine sent someone last year in response to a question about LHDH's and 750's. Good luck. -- Gail Rubin (grubin@bbn-spca or @bbn-unix)
info-vax@ucbvax.ARPA (06/05/85)
From: Ron Natalie <ron@BRL.ARPA> LHDH's don't plug into the backplane so there is no NPR jumper to remove. I use two 10 foot cables on mine, and it works fine. -Ron