on 10/12/03 7:12 PM, [EMAIL PROTECTED] at [EMAIL PROTECTED] wrote:
> I know now that the second hard drive (pulled from another machine) needs a
> different SCSI ID number and that you accomplish this with jumpers. What are
> jumpers, where do you get them, and where do you put them?
>
> Bailey
On some drives jumpers are placed on sets of pins the stick out the front of
the drive near the molex and scsi connectors. These are itty-bitty. On
some drives there are rows of pins on the schematic boards (green boards)
on the bottom of the drive. On others they are on the other end of the
drive from the front. (I guess that is the case with scsi drives) as the
molex and 50 pin scsi (narrow, yet wide to look at) connectors take up the
entire 3.5"s These are itty-bitty teeniney. (Tech terms). If you get out a
magnifying glass and get some really good light, you can read all sorts of
itty-bitty print on the boards (sometimes) and there are sometimes tables
on the drives explaining ID and other settings. Oh yeah, jumpers are itty
bitty (or teeniney) things that bridge two pins (often brown in color).
There are all sorts of things that can be turned on and off by the jumpers,
and at some point I had a marginal grasp of them, but they seem to have
faded. Termination power was one, auto spin up, and the scsi addresses. I
was saved from learning too much about this stuff by beer. If you have a
bunch of junk boards and drives and cards lying around, you can usually find
some jumpers on them if you look hard. If you don't have any of that kind of
stuff around, trying to find them is unreasonably difficult. I'm looking at
a Seagate 50 pin scsi drive right now and it has a block of jumpers on the
end away from the power etc. and there are 6 pairs of exposed pins, and
four pair that are capped by a small block that amounts to four jumpers. On
the label of the drive there is a schematic that gives some abbreviations
for stuff on the HDA (whatever that is) representing the six sets of pins on
the obverse (or assend) (itty bitty)of the drive and another schematic for
the pins on the bottom (belly) of the beast (itty-bitty teeniney):
TP to Bus
TP from Drive
Reserved
Parity Disable
Write protect (hey kewl)
Motor Start Disable
Delay Motor Start
Term Enable
The schematic for the ones on the butt of the drive, the ones you want for
scsi id are
(left to right)
Inexplicable symbol meant only for people who know what they are doing
Res (reserved)
Res (reserved)
4
2
1
the latter three joined under the agis of one { on its side beneath which
lie the important letters forming an abreviation for address; ADDR. If you
pin none of these, the address is 0, I think, and if you vertically bridge
any of the given numerals, that address will result. There are arcane
combinations of lateral bridging possibilities amongst these same pin sets
that will result in id's 3,5,6,7, I think. You can master this business at
your own preferred pace and to your own level of satisfaction, but it will
never be as easy as smashing the crap out of a dead drive or two and never
as fulfilling (the magnets in the dudes are kewl)
--
All the best,
R.A. Cantrell
<[EMAIL PROTECTED]>
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