Need help setting up SCSI drive

dougal

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I've got to SCSI drives by Seagate which are approx 1.0GB each. No idea if they work. I'd love to use them in my Amiga's as I've got an A2000 without a HDD but has scsi card and my SupraDrive 500XP has a dying drive.

They are NOT 50 pin but I had bought an adapter a while ago from the other bay which converts them to 50 pin and has a plug for power molex. They power up fine but i've no idea how to set them up.

Using SupraBoot when detecting/finding SCSI device, upon each ID (1,2,3,etc..) the HDD clicks once when it is scanning each number.

There is jumpers on the HDD for SCSI ID and also on the converter for SCSI ID.

Please help!
 

Beavis

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And what does Supraboot tell you?
I assume that you've got (U)W drives, so you will have to set the bus width on the drive, but without knowing the type nobody can tell you.....
And it can also be an SCA drive, and having read your other thread, it could well be that the A500 PS just doesn't hack it.
Does the drive spin up, or just clicks?
 
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dougal

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SupraBoot says no SCSI devices found.

I am hopeless at SCSI devices. If it won't work first go i'd be totally lost.

If I take photos of the drive and the adapter will that help ?

And what does Supraboot tell you?
I assume that you've got (U)W drives, so you will have to set the bus width on the drive, but without knowing the type nobody can tell you.....
 

roy_bates

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mine is 68 pin with an adapter with active termination plugged on the end,without the termination the drive didnt show.
 

dougal

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Here are some pics
efde060f9fdbeaf828ca3808f20eb3a4.jpg

5b85e22f7f8ffa63e0a8420d23b80dbf.jpg

6e003ceb169631794cb1b43a0e4f13d2.jpg


I will like to use the hard drive in my SupraDrive 500XP
 

Beavis

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So it's an SCA then, try to pop a jumper on the MTR pins, and see if it will spin up, but these HD's are quite picky when it comes to power consumption, so it could be that it will try to spin up, but that your setup is just a bit short of energy...
BTW, an A590 PS is compatible with the Supra. :)
 
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dougal

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The HDD is spinning up when powered as it is. Would a jumper on mtr help ?
 

Beavis

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If it spins up, then it's ok, so either the drive is not ok, or it doesn't know how to communicate with the Supra, or your Supra ain't that well.
Mind you, the Supra was launched before wide SCSI was born, on a lot of drives you can select between 8 or 16 bit, but not on this drive.
As it happens, I do have a few 50P Hawks, and they work a treat in an A3K.
I have tried a lot of SCA drives in a Casablanca, but not all of them were even willing.
Termination could also be an issue, so unfortunately this won't answer your question, you need some knowledge and reference material to solve the problem.
 

BLTCON0

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mine is 68 pin with an adapter with active termination plugged on the end,without the termination the drive didnt show.

Some (most?) wide drives will refuse to negotiate in narrow mode unless some bias voltage is present on the high byte lines. It's not termination that does the trick but this bias voltage, so a wide-narrow converter with active high-byte termination will coincidentally do the trick nicely.
Seagate drives worked great with simple, cheap passive converters. Western Digital ones were a different story.
The obvious trick to overcome the problem if only a passive adapter is available is to place the drive last on the bus and enable the drive's own termination and termination power. Not a real solution with three such drives :)

dougal said:
The HDD is spinning up when powered as it is. Would a jumper on mtr help ?
MTR will simply not spin-up the drive until the START command is send from the host adapter, it's not even a particularly useful setting in this case.
As Beavis said, don't keep your hopes up with SCA drives. They may sell for next to nothing and seem good bargains and all that, but they're tailor-made for hot-swap enclosures who take care of any and all settings, so these converters really only work well in wide SCSI environments, with external active terminators.
There's no way to force a bias voltage on the high-byte lines without hacking the drive itself, since by design SCA drives eschew termination options, so if the drive refuses to negotiate in narrow mode it's a no-go. That said, this is a Seagate drive so chances are it behaves well in narrow mode. Assuming that, the problem must be in termination/termination power, which as said is absent with SCA drives.
So you will need an external active terminator AND a way to supply termination power to it, because neither the Seagate SCA drive nor the antiquated Supra controller will provide it because the SCSI-1 standard it follows only requires passive termination. The easiest way to supply termination power is by means of another, non-SCA, single-ended drive, but a) you can't have two drives in the Supra and b) if you had one there'd be no need to use the SCA one in the first place. So if you MUST use this one, you'll need to hack termination power onto the SCSI bus somehow.
Bottom line: SCA is a bad idea. Get a regular 50-pin drive.
 
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Beavis

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I don't completely concur with BLTCON0, the MTR-on can be hardwired, and his drive does spin up, but there's also the issue with the bus width, which sometimes is auto detect, and sometimes must be hardwired, his drive however does't have the latter option.
And since this is a SE drive, there's no LVD issue.
As for termination, the internal cable is so very short, that the drive doesn't need to be terminated.
I have sold quite a few HDDs for the Casablanca, but finding the right drive was a proper PITA, I can tell thee.:picard
 
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BLTCON0

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I don't completely concur with BLTCON0, the MTR-on can be hardwired, and his drive does spin up,

But would they hardwire it on an SCA drive? That'd defeat the purpose. They're supposed to be externally controlled to the maximum. Unless you mean some override jumper onboard the drive has been set.

but there's indeed the issue with the bus width, which sometimes is auto detect, and sometimes must be hardwired, but his adapter provides in this.
And since this is a SE drive, there's no LVD issue.

An adapter cannot change the drive's policy on expected bus width though - so if the drive must see 16 bits, this adapter won't do. The positive thing is it's a Seagate drive, all wide ones I've encountered negotiate well in 8-bits, but then again I've never tried this or generally a Seagate SCA one.

As for termination, the internal cable is so very short, that the drive doesn't need to be terminated.
I have sold quite a few HDDs for the Casablanca, but finding the right drive was a proper PITA, I can tell thee.:picard

It's indeed possible to skip termination with bus lengths of stub size (<10 cm), but would it be wise to count on it when troubleshooting? The way I see it, this drive should first be verified in a more "welcoming" environment and then attempted as an Amiga drive. It's indeed a PITA.
I'm not familiar with the Casablanca but didn't it by default have a wide-SCSI interface? That'd ease things somehow with SCA-conversions.
 

Beavis

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The MTR-on is present on the SCA connector, else it wouldn't make sense to have the option on the converter.

I f'ed up a little bit with the post you quoted, so I edited it later on, if the N/W option is present, then it's on the drive, but not on this one, and now we're at it, I don't really recall having seen that option on SCA's, on 68 pin drives they do exist though.

And the Casa has only a 50P SCSI interface, and I'm talking about the classic, but I have successfully fitted several SCA drives in them.
 

BLTCON0

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The MTR-on is present on the SCA connector, else it wouldn't make sense to have the option on the converter.

Yes, of course. I'm not saying anything different. With respect to the drive, the adapter's MTR jumper is "external configuration". But the drive might still provide onboard override jumpers - i.e. if onboard jumper is set, the drive spins up when sent a START_UNIT command and not immediately when power is applied, and ignores the SCA connector's MTR setting. If onboard jumper is not set but adapter's MTR is set, same result. If both jumpers not set, drive start up immediately (or the converse, depending on jumper setting interpretations).

I f'ed up a little bit with the post you quoted, so I edited it later on, if the N/W option is present, then it's on the drive, but not on this one, and now we're at it, I don't really recall having seen that option on SCA's, on 68 pin drives they do exist though.
Exactly, this option will never be found on a SCA drive. On some 68-pin ones yes, but from what I can recall from my back in the day SCSI endeavors it's uncommon. Usually it won't be there and the drive will simply either be well-behaved on a narrow bus or require a wide bus (or high-byte termination tricks).
And the Casa has only a 50P SCSI interface, and I'm talking about the classic, but I have successfully fitted several SCA drives in them.
[/quote]
Must have been of the well-behaved variety :)
 
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