Very Computer

by **Christopher Tid** » Tue, 04 May 2004 07:16:20

Hello everyone,

I'm trying to set up a Fujitsu MAG3091LC disk as external storage for my
Sun Ultra 2. I've bought a SCSI SCA 80-pin to 50-pin adaptor and
installed the disk in a standard 50-pin SCSI box, but I can't get it to
work. The disk spins up when switched on but "probe-scsi-all" doesn't
find the disk (there is no entry in the listing at all). I know the disk
works as I've tested it in one of my internal bays, and I've checked
there's no conflict of SCSI IDs. I've also tried the disk and adaptor in
a second external disk box, which I know to be in good working order,
but it gives the same result. The adaptor itself is extremely simple so
I'd be surprised if it was broken. Has anyone had similar problems with
these adaptors? Perhaps there's something simple which I'm missing?

Any help would be much appreciated.

Many thanks,

Chris Tidy

PS: I'm also looking for an external SCSI box to house a zip drive.
Does anyone in the UK have a surplus box they'd be prepared to sell
cheaply? Sun, Mac or PC, 50- or 68-pin, pretty much anything will do. A
broken Sun or Apple CD-Rom would be fine if the drive could be removed
from the case.

by **Thomas Schu** » Wed, 05 May 2004 00:44:25

Quote:>Hello everyone,

>I'm trying to set up a Fujitsu MAG3091LC disk as external storage for my
>Sun Ultra 2. I've bought a SCSI SCA 80-pin to 50-pin adaptor and
>installed the disk in a standard 50-pin SCSI box, but I can't get it to
>work. The disk spins up when switched on but "probe-scsi-all" doesn't
>find the disk (there is no entry in the listing at all). I know the disk
>works as I've tested it in one of my internal bays, and I've checked
>there's no conflict of SCSI IDs. I've also tried the disk and adaptor in
>a second external disk box, which I know to be in good working order,
>but it gives the same result. The adaptor itself is extremely simple so
>I'd be surprised if it was broken. Has anyone had similar problems with
>these adaptors? Perhaps there's something simple which I'm missing?

Doed the adapter terminate the unused SCSI pins? If not, than the adapter
is too simple. If the unused lines are not terminated, the disk will not
understand that it is on a 50 pin buss and will not work. Note also that
when used on a 50 pin buss, the SCSI ID must be below 7.

Quote:
>Any help would be much appreciated.

>Many thanks,

>Chris Tidy

>PS: I'm also looking for an external SCSI box to house a zip drive.
>Does anyone in the UK have a surplus box they'd be prepared to sell
>cheaply? Sun, Mac or PC, 50- or 68-pin, pretty much anything will do. A
>broken Sun or Apple CD-Rom would be fine if the drive could be removed
>from the case.

--
Tom Schulz

by **Christopher Tid** » Wed, 05 May 2004 05:16:36

Quote:>>I'm trying to set up a Fujitsu MAG3091LC disk as external storage for my
>>Sun Ultra 2. I've bought a SCSI SCA 80-pin to 50-pin adaptor and
>>installed the disk in a standard 50-pin SCSI box, but I can't get it to
>>work. The disk spins up when switched on but "probe-scsi-all" doesn't
>>find the disk (there is no entry in the listing at all). I know the disk
>>works as I've tested it in one of my internal bays, and I've checked
>>there's no conflict of SCSI IDs. I've also tried the disk and adaptor in
>>a second external disk box, which I know to be in good working order,
>>but it gives the same result. The adaptor itself is extremely simple so
>>I'd be surprised if it was broken. Has anyone had similar problems with
>>these adaptors? Perhaps there's something simple which I'm missing?

> Doed the adapter terminate the unused SCSI pins? If not, than the adapter
> is too simple. If the unused lines are not terminated, the disk will not
> understand that it is on a 50 pin buss and will not work. Note also that
> when used on a 50 pin buss, the SCSI ID must be below 7.

Thanks for the suggestion - this seems quite likely as the adaptor is
very simple. How can I tell for certain if the adaptor terminates the
unused lines? I bought the adaptor on eBay and you can see a picture of
it at the following URL:

http://cgi.ebay.co.uk/ws/eBayISAPI.dll?ViewItem&item=4125914735

Many thanks,

Chris

by **joe durusa** » Wed, 05 May 2004 21:26:10

> >>I'm trying to set up a Fujitsu MAG3091LC disk as external storage for my
> >>Sun Ultra 2. I've bought a SCSI SCA 80-pin to 50-pin adaptor and
> >>installed the disk in a standard 50-pin SCSI box, but I can't get it to
> >>work. The disk spins up when switched on but "probe-scsi-all" doesn't
> >>find the disk (there is no entry in the listing at all). I know the disk
> >>works as I've tested it in one of my internal bays, and I've checked
> >>there's no conflict of SCSI IDs. I've also tried the disk and adaptor in
> >>a second external disk box, which I know to be in good working order,
> >>but it gives the same result. The adaptor itself is extremely simple so
> >>I'd be surprised if it was broken. Has anyone had similar problems with
> >>these adaptors? Perhaps there's something simple which I'm missing?

> > Doed the adapter terminate the unused SCSI pins? If not, than the adapter
> > is too simple. If the unused lines are not terminated, the disk will not
> > understand that it is on a 50 pin buss and will not work. Note also that
> > when used on a 50 pin buss, the SCSI ID must be below 7.

> Thanks for the suggestion - this seems quite likely as the adaptor is
> very simple. How can I tell for certain if the adaptor terminates the
> unused lines? I bought the adaptor on eBay and you can see a picture of
> it at the following URL:

> http://cgi.ebay.co.uk/ws/eBayISAPI.dll?ViewItem&item=4125914735

> Many thanks,

> Chris

Open it and see if you see resistor packs, or get a copy of the scsi pinouts,
and see whether you can read resistances across the pins that don't pass
through.

Just one additional thought - some scsi devices are differential, and some are
single-ended, and never the twain shall meet (at least not without a fairly
complex device between them.) You might ask the disk vendor what
kind of SCSI interface it has (e.g single-ended, differential, 8-bit, 16-bit)
and see what they say.

Speaking only for myself,

Joe Durusau

by **Thomas Schu** » Thu, 06 May 2004 00:42:18

>> >>I'm trying to set up a Fujitsu MAG3091LC disk as external storage for my
>> >>Sun Ultra 2. I've bought a SCSI SCA 80-pin to 50-pin adaptor and
>> >>installed the disk in a standard 50-pin SCSI box, but I can't get it to
>> >>work. The disk spins up when switched on but "probe-scsi-all" doesn't
>> >>find the disk (there is no entry in the listing at all). I know the disk
>> >>works as I've tested it in one of my internal bays, and I've checked
>> >>there's no conflict of SCSI IDs. I've also tried the disk and adaptor in
>> >>a second external disk box, which I know to be in good working order,
>> >>but it gives the same result. The adaptor itself is extremely simple so
>> >>I'd be surprised if it was broken. Has anyone had similar problems with
>> >>these adaptors? Perhaps there's something simple which I'm missing?

>> > Doed the adapter terminate the unused SCSI pins? If not, than the adapter
>> > is too simple. If the unused lines are not terminated, the disk will not
>> > understand that it is on a 50 pin buss and will not work. Note also that
>> > when used on a 50 pin buss, the SCSI ID must be below 7.

>> Thanks for the suggestion - this seems quite likely as the adaptor is
>> very simple. How can I tell for certain if the adaptor terminates the
>> unused lines? I bought the adaptor on eBay and you can see a picture of
>> it at the following URL:

>> http://cgi.ebay.co.uk/ws/eBayISAPI.dll?ViewItem&item=4125914735

>> Many thanks,

>> Chris

>Open it and see if you see resistor packs, or get a copy of the scsi pinouts,
>and see whether you can read resistances across the pins that don't pass
>through.

From what I can see in the picture, there are no terminators provided. It
is possible that there is something on the other side of the board. A quick
look at the drive specifications suggests that there is a jumper on the disk
to force the drive to be an 8 bit device. If so, installing that jumper
should fix it.

Quote:
>Just one additional thought - some scsi devices are differential, and some are
>single-ended, and never the twain shall meet (at least not without a fairly
>complex device between them.) You might ask the disk vendor what
>kind of SCSI interface it has (e.g single-ended, differential, 8-bit, 16-bit)
>and see what they say.

Many drives (most?) can switch between single-ended and differential. If
the documentation that came with the drive doesn't say, try the Fujitsu
web site. They have the manual there in PDF format.

Quote:>Speaking only for myself,

>Joe Durusau

--
Tom Schulz

by **Darren Dunha** » Thu, 06 May 2004 01:58:29

>>single-ended, and never the twain shall meet (at least not without a fairly
>>complex device between them.) You might ask the disk vendor what
>>kind of SCSI interface it has (e.g single-ended, differential, 8-bit, 16-bit)
>>and see what they say.
> Many drives (most?) can switch between single-ended and differential. If
> the documentation that came with the drive doesn't say, try the Fujitsu
> web site. They have the manual there in PDF format.

You are thinking of SE and LVD (low-voltage differential). Much sun
equipment labeled "differential" is HVD (high-voltage differential).
Because the voltages and singalling are significantly different, I know
of nothing that will autoswitch between HVD and anything else.

Even so much as attaching the wrong terminator to the bus would be
sufficient to prevent anything on the bus from working.

--

Senior Technical Consultant TAOS http://www.taos.com/
Got some Dr Pepper? San Francisco, CA bay area
< This line left intentionally blank to confuse you. >

Very Computer

Problems with SCSI SCA 80-pin to 50-pin adaptor

Problems with SCSI SCA 80-pin to 50-pin adaptor

Problems with SCSI SCA 80-pin to 50-pin adaptor

Problems with SCSI SCA 80-pin to 50-pin adaptor

Problems with SCSI SCA 80-pin to 50-pin adaptor

Problems with SCSI SCA 80-pin to 50-pin adaptor

Problems with SCSI SCA 80-pin to 50-pin adaptor