#New External HD
22 messages in this thread
Ok – Tech Wizards
I've got me a problem, maybe somebody can help.
I've just aquired a 380meg Full Hieght Maxtor SCSI HD – with it's own
External case & power supply. This is going to be a great unit for me, if
I can get over a few problems I seem to be having.
I think I have a couple of different problems here and I will attempt
to explain them both in detail.
Problem 1) I think the Maxtor may have been damaged in shipment
somehow. Systoms appears that the drive itself is clicking as soon as
power is supplied to the drive. This is without a SCSI cable applied to
the drive. (just power) It's internal light blinks and sounds like the
head is knocking. Am I having a spinup problem? Do to problem #2 I can
not send any sort of commincation to the drive from the computer and I
have no docs on this drive, except a factory bad block list. I'm thinking
of trying to connect this drive up internally in order to send it a format
command of some sort (I just thinking maybe if I send is an instruction of
some sort it will jar the head into moving again – dumb idea, huh)
BTW – the case has an external number thingy to set the drive address,
however in my attempts to look at this drive I pull the jumper plug off
the back of the drive. Hmm, guess what – I have no idea which group of
nine pins, the six hole plug goes into? Nor the orienation (sp?) of this
plug. Does anyone have a clue – I can draw the pins if it would help.
On to problem #2
The SCSI cable for this box I purchase separately from Redmond – they,
of course know about the Amiga's 2091 port and about the parallel type
plug on the back of the external case. Anyway, as soon as I plug this
cable into the external 2091 port my DH0: and DH1: drives (internal) do
not function. This is with the cable just plugged into the port and not
conntected to the external drive. I'm not sure if I have a problem with
the cable, the 2091 card or what.
BTW – I have two internal drives connected to the card. One mounted on
the card, the other in the drive bay. They both, I believe still have
their terminators in. Should I take them out of one of them? But I
didn't think that this seems like a terminator problem. My thinking is
either there is some sort of short in the cable, or maybe a problem with
my card – like maybe I need a updated ROM (it's a pretty old card).
Well I've gone on to long. I'm hoping some one has a idea here. Don, I
addressed this to you just cause I know you know about drives. But really
if anyone has a clue, please pitch in here. Tonight I think I'll try to
hook up one of my internal drives into this external case, just to see if
the cable is working or not.
Let me know what you all think – Thanks.
OnLine since 1982
Roy Pahnke – Casper WY
Roy,
The drive may have a 'motor control' jumper that (usually when off)
says don't spin up until you receive a spinup command from the host system.
The SCSI ID goes on pins that are *usually* labeled a0, a1 and a2 with
the white stripe on the connector going to a0.
Yes, only one drive should be terminated. That cable plugged into the
back becomes a long "stub" that can interfere with the operation of the SCSI
bus.
Don
Don –
Over the weekend I have been working on things and have come to the
conclusion that the problem is not with the drive. (It is now formated and
ready to go)
The problem is down to either the 2091 card, or the cable purchase from
Redmond. You said;
–> " Yes, only one drive should be terminated. That
cable plugged into the back becomes a long "stub" that can interfere with
the operation of the SCSI bus."
Well, I'm stumped? My configuration, as far as HD's are, 2 internal
drives – DH1: on mounted on the card and terminated, DH2 mounted in drive
bay and terminators REMOVED. The ribbon cable puts the controller card in
the center and the two drives on either end. This has been my setup for
quite some time and works. It is my understanding that the internal
drives are one end of the SCSI chain and the external is another end.
Therefore one drive internally is terminated and the drive that is
external should also be terminated. If this is not true, please be so
kind as to explain it to me.
Anyway. As soon as I connect this SCSI cable to the 2091 then my
internal drives go down. I have experimented with removing the
terminators on the internal drive and a couple of other combinations but
nothing seems to work. I'm begining to think something is wrong with the
card. Mybe my ROMs aren't upto date (This is a early production card –
v4.0modified w/ both roms reading v6/1). Are there terminators on the
card? I couldn't find any, but had to ask.
What do you think I shoud try to help figure out the problem.
Remember, things start to fail with just the cable pluged in (not attached
to anything. It that what you meant by long stub?) I have tryed moving
my working drives to the external box with cable plugged in and things are
the same. I'm lost here – any ideas.
OnLine since 1982
Roy Pahnke – Casper WY
Roy,
Right now, your setup looks like this:
HD…….2091……HD
When you add the cable (with nothing plugged in) it ends up
looking like this:
HD…….2091……HD
|………………………cable
A SCSI bus is the 50 wire cable…nothing else. It must be terminated
at each end (the 2091 does NOT have terminators on it). A stub is a 'T' off
of the main cable like this:
……………..cable……………………
| <–stub
They can be no longer (per the spec) than 4" if you look at the
drawing above, you can see the cable you plugged into the back is a 'stub'
and certainly longer than 4". IF you plug the cable into a terminated
drive, things should start to work.
BTW, your 2nd internal HD is on a stub now…and probably longer
than 4", but probably not that bad. You *may* have to reroute your
cable like this to get things to work right:
HD…..HD…..2091….cable to external drive……(new HD TERMINATED)
^ ^
| |…..NO terminators here
….terminators here
From the 2091 manual:
'If multiple SCSI hard disk are connected to the A2091, you will need
to remove the terminator packs on all but the last external SCSI device in
the chain and all but the last internal SCSI device in the chain.'
Don
Don –
Thanks, you do have a handle on my situation 🙂 (I had thought that my
explanation without diagrams was getting a bit confusing).
Yes my cable is longe than 4" – it's an off the self cable at about 6'.
–>"IF you plug the cable into a terminated drive, things should start to
work." <–
Oh, believe me, I have tryed this with the cable plugged into the box
and the drive is terminated. The systoms are the same. This was my first
move — Plug everything it and it all will work – ya, right :(.
Somethings are clearing up for me. There is one correction to my current
set up;
HD…….2091……HD <— No teminators
|………………………cable <– Drive in box
has terminators
Ok – I will attempt the reroute of the internal drives (although I
thinking that this won't make that much difference, seeing as one of my
internal drives already has Terminators removed my current internal
cableling is essentially the same. I will also attempt to get a new
SHORTER cable from Redmond, but 4" is really short (it's about 6" for the
SCSI port to the left edge of the computer). And your diagrams have made
me notice this external box in a new light. The box has 2 Mac type SCSI
ports on it (with the assumption of furture chainning of SCSI devices.)
But the way it is wired internally it puts the HD in the center of the 2
ports.
SCSI Port……HD……SCSI Port <–Port out is actually the end
^ ^ of the line. It's the new stub.
| HD Terminated
..Cable in
Should that SCSI Port be terminated some how? Maybe I'll ask Remond if
they have some sort of terminated plug that I can put in the bottom port.
Course, maybe this doen't matter cause it just like the External port on
the 2091 hanging open all these years. Maybe I'm just shootin in the dark
with that suggestion. Oh well, I will perform the rerouting of internal
cables and get a shorter external cable, and hope that it solves the
problem. But – if it doesn't, as Arnold has said, I'LL BE BACK!
Thanks for your help and the diagrams.
OnLine since 1982
Roy Pahnke – Casper WY
Roy,
You don't need a shorter internal or external cable. You just need to
put a terminated drive at the end of each cable.
Just route the internal cable so the last drive on it has the
terminators, not the drive in the middle as it appears you have now.
On the line to the external box, make sure it's a SCSI cable, not just
a serial type cable. The 25 pin connectors don't carry all the grounds, so the
cable should have shielded wires with the shields connected to the common
ground in the connectors.
Yes, you could put a terminator plug on the external port of the
external box…IF you remove the terminator plugs from the drive inside the
box.
Don
Don –
We are moving right along with this. Yesterday I did switch around the
internal cable so that the 2091 is on one end the non-terminated drive is
in the middle and the terminated one is on the end. Then tryed it all
again. — No Go —
Same results, niether the internal or external drives will mount. When
the external cable is plugged into the 2091 the entire HD system fails.
I'm sure now that all the proper drives are terminated and that the
cables are routed correctly, yet I get nothing from the external box.
I'm going to double check w/ Redmond probably will order a new
specially built – shorter, sheilded SCSI cable from them. (Like I said the
one I've got is just an off the self Mac type.
Otherwise, I don't know much else to do. Maybe I'll post another
message asking others if they have had troubles with their 2091 cards and
External Drives.
Thanks for all you help so far. Why is it I was hoping for just a plug
and go setup. ;(
OnLine since 1982
Roy Pahnke – Casper WY
Roy,
Ok…have you by any chance had the cable checked out? It's always
possible it's defective. If you have a simple ohmmeter, you could do a pin to
pin check of the cable…making sure each pin is carried thru to the same pin
on the other end (continuity) and not to any of the other pins (no shorts).
Don
Don
No I have not checked the cable out, but I think it is the cable. I
have ordered a new one from Redmonnd. It will be double shielded, grounds
tied together, checked (and double checked) for Amiga 2091 spec, and 4'
long. Redmond with RMA the one I have and really hoping that it fixes my
problems.
As I have said the systoms (sp?) are all ways the same. As soon as I
plug in the cable to the Amiga, the internal HD's go down and the external
one is not recognized at all. It doesn't matter if the cable is hooked up
to the external box or not, the internal drives quit working. It's got to
be the cable! Or something is wrong with the 2091 card.
Well that's how it stands now. Will let you know when the new cable
comes in.
Thanks, of course, for all your help.
OnLine since 1982
Roy Pahnke – Casper WY
In my experience, and from what I have been told, resistor packs are not THAT
important. At the risk of sounding pretentious, I've never bothered with them,
and I've never had a problem of that nature. Perhaps you should look to some
other cause. I find It hard to believe that the length of SCSI cable is
relevant in this case also. I have 3 drives running on my system, one on the
2091 card, and one drive in front of the power supply and one in the 3.5 inch
bay. admitedly I have no external SCSI drives, but I do have 3 on an internal
chain. I would suggest checking the SCSI ID of the drives and make sure that
you don't have more than one drive set to SCSI address 0 or something. this
would cause a conflict. Possibly also check whether the drives are set to
bootable or not etc.
( Do they appear at all in HD toolbox ?)
Apologies for the formatting of this message, I don't use AP yet.
Please mail me (76711,712) if I seem to be on the right track, and I will try
to help further.
Muzz
Proper SCSI termination *is* important. It's an unfortunate fact that SCSI
hardware is robust enough that even improperly terminated chains will continue
to function. Maybe you should change your rule to "resistor packs are not that
important, unless you're in a situation where they are important."
> Proper SCSI termination *is* important.
Nice to know I got lucky for once 😎
Muzz
Muzz
As I posted to Don, I think the problem is in the cable. I have
ordered a new one and will wait and see.
I have 2 internal drives that work perfectly until the cable is plugged
in to the external port on the 2091 card. It doesn't matter if the other
end of that cable is plugged in to the external box or not. The result is
always the same – in that, the act of plugging in the cable with bring
down my internal drives.
I have been able it plug my new drive on to an internal cable (had to
take one of the other drive off) and format the drive. Unfortunately it
is a 380 meg Full Height drive that will no way fit permanately inside the
Amiga's drive bays. But I had it there for a while and set it all up. My
drive address numbers are #1 -DH0:(Workbench) 40meg & bootable,
#6 -DH1: & DH2: 150meg in two partitions both not bootable, and the new
drive will be addressed at #2 -DH3: & DH4: 316meg (Formated) in two
partitions and both not bootable.
Thanks for jumping in, I'm in a wait and hold pattern til the new
cable comes in. And if that don't work, then I don't know what the next
step will be.
OnLine since 1982
Roy Pahnke – Casper WY
Roy
I've been reading your messages on trying to hook up your external
harddrive. It sounds very much like the problem I had hooking up an
external tape drive. My two internal drives are set up the same as you
have yours set up. I'm using a GVP controller in an Amiga 2000.
When I first hooked the tape drive up, the computer wouldn't even boot
most of the time and when it did I got all sorts of warnings about bad
blocks on both internal drives. I was using a 3 foot scsi cable with the
terminations right on the tape drive. I sent for a 6 foot cable and an
external termination plug. The longer cable solved the bootup problem, if
I removed the terminations on the tape drive, but I couldn't get a
complete backup tape made without the computer hanging. The external
termination plug always caused a 'no bootup'. I tried installing the tape
drive in the computer with the number two hard drive external, again
warnings of bad blocks on the hard drives.
When I put everything back, drives internal – tape external, the
computer wouldn't bootup at all if the tape drive was hooked up with the 6
foot cable which had, at least, kind of worked before. Believe me I
understand you frustration! I tried the 3 foot cable again and – It
Worked! So I tried it with the 3 foot cable and the termination but No Go.
I know this isn't the way it's supposed to be but at least it works.
Why did it start to work with a cable that it would not work with
before?
Either reseating the cards and connectors in the computer or possibly I
slightly changed the routing of the internal scsi cable.
Why will it work with a 3 foot cable and not a 6 foot cable?
Perhaps with no terminaton, the cable is acting as an antenna and I am
tuning it pick up or not pick up outside noise by changing the length.
Why won't it work with the external bus terminated?
Damned if I know!
Why does scsi it ever work?
Voodoo I think.
There was one thing that I found that in my case didn't help but is
something to check. Be sure that the drive frame is connected to the
ground lug built into the external case. Don't count on the mounting
screws making a good ground. With the scsi cable hooked up you should see
no resistance between the computer chassis and the external drive case and
drive frame.
I wish I had the answer to your problem, but, if nothing else, know that
you're not the Lone Ranger with your scsi problems.
Doug Partridge – Helena MT
Thanks for your Experience, Doug.
My first cable was (still is, I guess 🙂 a 6' off-the-shelf, Mac type
SCSI cable. It didn't work at all, and a new 'Custom' made cable should
be arriving tommorrow. Will let all know if it works or not – And you'll
all be hearing crys for HELP, if it doesn't work. 🙂
BTW, did your internal drives continue working if the cable was plugged
into your control and not plug into the external box (Like, just plug the
cable in and let it hang..). My internal drives go down as soon as the
cable is plugged in. So I don't even know if the external box is ok cause
I can't get past the cable being plugged in.
OnLine since 1982
Roy Pahnke – Casper WY
Roy,
Double check to make sure that your drives have different IDs. I'm also
assuming that the drives you have are not formatted yet.
Regards,
John Chang
Technical Support Manager
Scala, Inc.
Has anyone checked the jumpers yet to make sure that the drives are not set to
the same SCSI address ? As far as I could tell, if there were two drives set to
the same address ie zero, then a conflict would occur. From my experience many
drives shipped from the factory require this set to get them working together.
Hope this is somehow useful..
Murray
Murray,
He gets the problem before he plugs the cable into the drive.
Don
>Murray, > He gets the problem before he plugs the cable into the drive.
Fair enough, well I'm out of ideas then 😎
Muzz
Hi everybody….
I got Golem SCSI Controller (german brand..) with an external SCSI Box. I'm
using an off the shelf Mac SCSI cable and it works fine… I'm running a
Quantum 240 internal, an Iomega floptical drive, a Seagate ST1096N, and a
Tandbergg 150MB streamer an got no problems… Termination is Internal Quantum
and last in external chain, Iomega floptical…
It's possible that the controller has an on board termination for the external
port, for proper termination while there is no external drive connected. This
termination can usually be switched off by setting a jumper or pulling resistor
packs (same principle applys for IBM-PC Adaptec controllers).
Maybe this helps.
Axel
Greetings from Hamburg, Germany
Axel,
PMFJI but I've got a Tandberg tape drive which I'm having terrible
problems getting to work, can you help me with the following;
1. what does your SCSI bus report the Tandberg as?
2. how is the rear of your Tandberg set up (what pins are shorted)
3. what backup software are you using?
Thanks in advance…
Kevin 68030/40 A1200…
On AutoPilot from Surrey in the UK