ward@cfa.harvard.EDU (Steve Ward) (01/24/89)
I have a DEC RD52 disk drive. The disk drive is made by Quantum and is also the Q540 Quantum disk drive. The drive is an ST506 MFM type. The drive works fine on my MicroVAX II using the RQDX2 controller. I have tried to install the drive on a standard MFM disk controller on a PC computer, but the controller always sees the drive as offline or not ready. Does anyone know of any "DECism" modification to the drive that must be undone before I can use it with normal MFM controllers? For example, I had the same identical problem with a DEC RD53 disk drive (really Micropolis 1325) until a jumper was removed from the drive printed circuit board, so there may be something similar to undo with the RD52. Thanks, Steve W. ...harvard!cfa!ward ward@cfa.harvard.edu
cww@ndmath.UUCP (Clarence W. Wilkerson) (01/26/89)
Some pc hard disk contollers (XT type) expect the drive to be jumpered as the second drive, and use a twist in the cable. This made a little sense for floppy drives, but hardly any for harddisks.
rr@sun2.cs.uh.edu (Ravindran Ramachandran) (01/28/89)
Hi, all. I am having an Ultrix cluster that consists of a 3200, and 2 2000's.
The 2000's are diskless, and at present the system has one RD54. I am
interested in purchasing some third party disks that are in the .5G to 1.2Giga
range, and the price in the 7K to 14K range. My problem is that though the
air-conditioning in the computer room is pretty stable, there is no special
equipment, and so I cannot have a disk that dissipates too much heat. I was
wondering if anyone has done a survey of the different disks offered. I would
be grateful if you could e-mail it to me. I'll post a summary, if anyone needs
it. My disk has to be in a seperate enclosure, and I'm really not sure if I
need another disk controller; I think I'm having a RQDX3 at the moment.
Thanks in advance,
-- Ravi.
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| Ravindran Ramachandran
Internet : rr@sun2.cs.uh.edu | System Administrator
: rr@csv1.cs.uh.edu | TCSUH, 617 SR1
CSNET : rr@houston.edu | University of Houston
BITNET : coschmd@uhvax1.bitnet | 4800, Calhoun
Phone : (713)749-3909 / 3202 | Houston, TX - 77204.
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Disclaimer : The opinions mentioned here are purely my own (most of the time);
however, sometimes my opinions are not THAT pure.pavlov@hscfvax.harvard.edu (G.Pavlov) (01/30/89)
In article <1044@uhnix1.uh.edu>, rr@sun2.cs.uh.edu (Ravindran Ramachandran) writes: > Hi, all. I am having an Ultrix cluster that consists of a 3200, and 2 2000's. > .... I am > interested in purchasing some third party disks that are in the .5G to 1.2Giga > range, and the price in the 7K to 14K range. My problem is that though the > air-conditioning in the computer room is pretty stable, there is no special > equipment, and so I cannot have a disk that dissipates too much heat...... > ... My disk has to be in a seperate enclosure, and I'm really not sure if I > need another disk controller; I think I'm having a RQDX3 at the moment. > Re controller: yes, you should get a new controller. Even if you could con- nect a high-performance disk up to the RQDX3, you would be wasting your mo- ney: you will gain the capacity of the additional disk but will not see any of its performance potential. There are good controllers on the market, including Dilog and Webster. One MAJOR word of caution: MAKE SURE that the particular controller model that is suggested to you (or you choose) is actually designed for the MicroVAX 3xxx series. Lots of systems integrators have been selling controller cards designed for the uVAX II into uVAX 3xxx systems. Avoid this, because these configurations do not meet RFI and grounding requirements. I know that Aviv has properly configured controllers and Dilog was developing one; I don't know about Webster. Re heat generation: I assume that a high-density 5 1/4" drive will generate apx. 1 to 1.5 kw heat (the only such drives that we have came without heat generation specs; I'm guessing; anyone else know for sure ?). If I am right then one or two such drives should not seriously hamper your air conditioning system, unless it was very marginal to begin with. One more thing about controllers: the third-party controllers I have worked with gave great performance with one drive. We use one controller per drive: for us, its still much cheaper than, say, a kda50, but in multi-drive configs, a kda50 will outperform the third-party controllers that we have used. greg pavlov, fstrf, amherst, ny