Relay-Version: version B 2.10 5/3/83; site utzoo.UUCP Posting-Version: version B 2.10.1 6/24/83; site ariel.UUCP Path: utzoo!watmath!clyde!burl!ulysses!mhuxr!mhuxn!mhuxj!houxm!vax135!ariel!jlw From: jlw@ariel.UUCP (J.WOOD) Newsgroups: net.periphs,net.wanted Subject: Re: Question about disk drives Message-ID: <804@ariel.UUCP> Date: Fri, 21-Dec-84 09:23:21 EST Article-I.D.: ariel.804 Posted: Fri Dec 21 09:23:21 1984 Date-Received: Sat, 22-Dec-84 02:10:23 EST References: <213@psivax.UUCP> <427@amdcad.UUCP> Distribution: net Organization: AT&T-ISL, Holmdel, NJ Lines: 39 Xref: watmath net.periphs:613 net.wanted:5410 We have had problems getting our RA-81s and 60s running well on UNIX System V. We sort of ported what was originally the Rice? Univ. BSD driver. When we bought the drives we also ordered dual UNIBUS adaptors so we could run the RAs off one UNIBUS and all the other junk off the other. We have had myriad problems. We hacked SV to add dual adaptor support but have never been able to get NPR devices to work on UNIBUS 1 (ie the second UNIBUS). Query, has anyone out there in netnewsland done this? Also in our rage of rewirings we discovered that with an expansion UNIBUS there are cartain configurations that don't work. This may not be too clear. We were in the throes of trying anything that would work. DEC recommends that the UDA50 be the last guy in the UNIBUS so the buckpassing lets other devices of the same priority class, in our case DZ/KMC and DMRs, get access first. Since the UDA hasbuffering it supposedly can stand some delays of the millisecond range while the others cannot. We had the UDA50 adaptor boards in the last slot of the internal 750 UNIBUS. We wanted a single UNIBUS system with this at the very end of the chain, so we went from the adaptor on the processor for UNIBUS0 out to the expansion cabinet and then back into the main cabinet to the internal slots. This configuration won't boot because of the power-up test sequence of the 750 powers the internal UNIBUS first and then the expansion box, causing the power up diagnostics to fail and lock the processor. Aw darn. So now we are running single UNIBUS and aren't too happy with the performance, and every once in a while the system crashes due to, we think, an interaction of the DMR11 (spell KMC11-DMC11) and the UDA50. Sigh. Joseph L. Wood, III AT&T Information Systems Laboratories, Holmdel (201) 834-3759 ariel!jlw