krowitz@RICHTER.MIT.EDU (David Krowitz) (11/16/90)
Has anyone tried connecting a non-HP SCSI disk to a series 400 machine? Is the SCSI disk driver for the new machines as willing as the DN2500's driver to accept almost any old SCSI disk you care to plug into the port? -- David Krowitz krowitz@richter.mit.edu (18.83.0.109) krowitz%richter.mit.edu@eddie.mit.edu krowitz%richter.mit.edu@mitvma.bitnet (in order of decreasing preference)
lampi@polari.UUCP (Michael Lampi) (11/17/90)
In article <9011152114.AA03708@richter.mit.edu> krowitz@RICHTER.MIT.EDU (David Krowitz) writes: >Has anyone tried connecting a non-HP SCSI disk to a series 400 machine? >Is the SCSI disk driver for the new machines as willing as the DN2500's >driver to accept almost any old SCSI disk you care to plug into the port? > > -- David Krowitz The series 400 machines are actually more robust with their implementation of SCSI than the DN-2500. For example, at ADUS I had a 9000 400t with an internal 200 meg Rodime, cabled to an external removable 200 meg Rodime, cabled to three fixed 660 meg drives, terminated there and connected to a removable 660 meg drive. A total of 25 feet of SCSI cabling, improperly terminated. (Why didn't I terminate it at the end? Because I forgot to bring the proper terminator for the SCSI connector on the removable 660. :( ). Anyway, the whole thing worked perfectly, even to the point of being able to dismount, power off and remove the removable drives while the system was up and running, and then to insert the drives and remount them! Of course, it helps to use good cables, connectors, etc., but I see fewer problems with the 9000 series 400 and different manufacturer's drives than I do with the 2500. Software wise, it seems more robust, too. Michael Lampi MDL Corporation (206) 643-7333 FAX (206) 643-5080 2667 170th Avenue SE Bellevue WA 98008
128.244.194.200 (tea-dgl-mac) (11/27/90)
To terminate or not terminate. That is the question. We have a 760MB Seagate disk and a 60MB cartridge drive attached to our new 400t w/ 2 internal 200MB drives using the SCSI bus. I knew from previous experiences with other computers that only the last device on the SCSI bus should be terminated and we dutifully pulled the terminators out of the Disk. To our great consternation we could mount the 760MB disk when the 400t was brought up diskless but the computer would not boot off of its own internal disks when the 760MB was plugged in. We must have INVOLed our 760 half a dozen times. Finally one of our techs suggested that we try putting the terminators back in and voila everything worked fine. This 400t now has 2 760MB drives and a cartridge tape all with terminators. We have brought up several other 400t machines with the 760MB disks and everything seems to be working fine. -- D. Gilbert Lee, Jr.
kinsell@hpfcdj.HP.COM (Dave Kinsell) (11/27/90)
>Finally one of our techs suggested that we try putting the terminators >back in and voila everything worked fine. This 400t now has 2 760MB drives >and a cartridge tape all with terminators. We have brought up several other >400t machines with the 760MB disks and everything seems to be working fine. Your experiences don't match anything I've seen while testing a 400s. The only legal configuration for SCSI is a linear bus with one terminator at each end (the 400 is terminated internally). This configuration should work fine if cable with proper electrical properties is used. With three external devices, you've got four loads on the bus, and are running some risk of burning out interface chips. >D. Gilbert Lee, Jr. -Dave Kinsell kinsell@hpfcmb.hp.com
tomg@hpcvlx.cv.hp.com (Thomas J. Gilg) (11/28/90)
> To terminate or not terminate. That is the question.
It depends on whether the device has a built in "passive terminator" (I think
thats what they call it?). With such a terminator, an external terminator
is not required (though many vendors will still suggest you use one).
Thomas Gilg
tomg@cv.hp.com