friesen@psivax.UUCP (Stanley Friesen) (12/20/84)
We have a VAX-11/750 and are thinking of buying a new disl drive. We would be interested in any information about the relative merits of the DEC RA-81 and the Eagle drive. Thank-you.
phil@amdcad.UUCP (Phil Ngai) (12/21/84)
> We have a VAX-11/750 and are thinking of buying a new disl drive. > We would be interested in any information about the relative merits of > the DEC RA-81 and the Eagle drive. Thank-you. When I priced everything out (including our corporate discount from DEC), the RA-81 came out almost price competitive with the Fujitsu 2351 (eagle). There were rumors about the RA-81's reliability but those seem to have settled down. And at least your dollars won't turn into yen. (the megabytes and milliseconds seem comparable too) I guess the UDA is a power hog, don't know how important that is to you. I have personally used the eagle and like it, I will probably try the RA-81 in the near future. -- This could very well represent my opinion and AMD's. Phil Ngai (408) 749-5790 UUCP: {ucbvax,decwrl,ihnp4,allegra}!amdcad!phil ARPA: amdcad!phil@decwrl.ARPA
jlw@ariel.UUCP (J.WOOD) (12/21/84)
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 has <extensive> buffering 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
henry@utzoo.UUCP (Henry Spencer) (12/21/84)
You get reasonably complete documentation with Eagles. Not so with the
RA81. This is not a trivial consideration. To give you some idea of
the situation on the RA81, if you can find out *how* *big* an RA81 is --
i.e. what's the last valid address on it -- the people at our computer
center would love to hear from you. They've got RA81s, and they've had
no luck getting this information from DEC (!).
If you think this is ridiculous, they will certainly agree with you.
--
Henry Spencer @ U of Toronto Zoology
{allegra,ihnp4,linus,decvax}!utzoo!henrychris@umcp-cs.UUCP (Chris Torek) (12/27/84)
RA81s are 891072 blocks (block==512 bytes). That's not including the
spare sectors used for bad block forwarding; that's the part you're
normally supposed to use.
--
(This line accidently left nonblank.)
In-Real-Life: Chris Torek, Univ of MD Comp Sci Dept (301) 454-7690
UUCP: {seismo,allegra,brl-bmd}!umcp-cs!chris
CSNet: chris@umcp-cs ARPA: chris@maryland