Re:
> SCSI is SCSI.
While I agree with the implied sentiment (be willing to try non-HP SCSI disk
drives), I disagree with the literal meaning...SCSI isn't "SCSI"...it's
a set of 2 to 5 (depending upon how you count) standards that are sometimes
incompatible with each other! It's extremely easy to puchase a "SCSI disk
drive" that won't work on your particular HP 3000.
There are two kinds of SCSI adapters on the HP 3000: Single Ended SCSI
and Fast/Wide Differential SCSI. Every 9x7 and most 9x8s I've seen have
Single Ended SCSI card ... although they may also have an added
F/W SCSI card, too.
(SCSI standards don't require Fast/Wide to always be Differential,
nor vice-versa ... but HP only makes 2 adapters for the 3000:
Single Ended (SCSI-2) and F/W Differential. Hence, all HP 3000 F/W
is Differential, all HP 3000 Differential is F/W)
What kind do you have? Find the Device Adapter in SYSGEN:
:sysgen
io
lp
56/40 LDEV:
ID: HP28642A-SCSI TYPE: DA
PMGR: SCSI_DAM PMGRPRI: 6
LMGR: MAXIOS: 0
PATH: 56/40.2 LDEV:
In this case, it says "SCSI_DAM", so it's a Single Ended SCSI (aka SCSI-2)
adapter. (CIO_SCSI_DAM is also Single Ended.)
The other possibility is "FWSCSI_DAM", which is a Fast/Wide Differential
adapter.
With Seagate, the last letter (or two) of a model tells you the kind
of interface (from http://www.seagate.com/support/kb/disc/discmodelinter.html):
and the rest of the model number tells you the form factor and number of
millions of bytes storage capacity (not MB, but simply millions):
E.g.: ST318275LW
= ST 3 18275 LW
= ST (SeagaTe), 3.5" drive, 18275 MB, LW interface
Form Factor
1 = 3.5-inch, half-height, 1.6-inch high
3 = 3.5-inch, low-profile (LP), 1-inch high
Interface
DC = Differential, 80-pin Single Connector Attachment (SCA)
FC = Fibre Channel, 40-pin SCA
FCV = Same as FC, but with an increased cache size
(Recommended for Video applications and applications
with large file formats)
LC = Low Voltage Differential, 80-pin SCA
LCV = Same as LC, but with an increased cache size
(Recommended for Video applications and applications
with large file formats)
LW = Low Voltage Differential, 68-pin Wide SCSI Connector
LWV = Same as LW, but with an increased cache size
(Recommended for Video applications and applications
with large file formats)
N = SCSI, 50-pin Narrow SCSI Connector
ND = Differential, 50-pin Narrow SCSI Connector
W = SCSI, 68-pin Wide SCSI Connector
WC = SCSI, 80-pin SCA (Hot Swappable)
WD = DIfferential, 68-pin Wide SCSI Connector
The ones ending in "N" are directly compatible with the standard
Single Ended SCSI on a "standard" HP 3000.
However, because Seagate (and others) seem to be phasing out the
"N" type drives (in favor of faster interfaces), we need to know a bit more...
The Seagate drives ending in "LW" can be connected (via a simple adapter)
to the standard Single Ended SCSI on a "standard" HP 3000. (We have such a one
installed, the adapter is inside the external case we put the drive in.)
(This conversion is possible because Low Voltage Differential is quite
a different beast than the older "Differential")
There may be other interfaces that can be connected via adapters...
but don't ask *me*! (I dimly recall trying to convert an LC (SCA)
with no success...but I'm not sure that's what it was.)
If you have a F/W Differential SCSI card, then you can use the
drives ending in WD. I don't know anything about using other interfaces,
however.
Recommendation: buy quality SCSI cables from Granite Digital (www.scsipro.com),
and terminate the chain with an "diagnostic terminator" (which has a couple
of LEDs to monitor the SCSI bus activity and termination power status).
I used to recommend buying cases (for external drives) from Granite
Digital, but they now use the same cheap ones that everyone seems
to use :( (I'd like to find a better made case, with better fans,
but under $150))
Stan Sieler [log in to unmask]
www.allegro.com/sieler/wanted/index.html www.allegro.com/sieler
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