I have an external SCSI device that I'd like to plug in on a 10-15' cable. The device has a standard dense 50-pin 2-row connector. I thought at first that meant for sure LVD, but now I'm thinking it just means ultra. I need LVD to get over 1.5M cable length, according to spec. LVD lets me go to 12M it appears. If it's just ultra then I'm SOL, I guess.
Is there a way to know what signalling this device uses based just on the connector? I checked all available interent specs, incl the original manual, for the device and *nothing* specifies anything other than "SCSI".
I'm a big SCSI guy, but my memory on the subject is starting to get hazy due to disuse...
Not 100% sure either, but IIRC LVDS (and just plain differential) never had its own connector. With the advent of ... Ultra160??? everything was lvds anyway. I recall a small handful of devices that could do differential or regular based on a jumper or dip switch, over the same connector. What's the device? -Adam
On July 3, 2015 4:06:19 PM CDT, Trevor Cordes trevor@tecnopolis.ca wrote:
I have an external SCSI device that I'd like to plug in on a 10-15' cable. The device has a standard dense 50-pin 2-row connector. I thought at first that meant for sure LVD, but now I'm thinking it just means ultra. I need LVD to get over 1.5M cable length, according to spec. LVD lets me go to 12M it appears. If it's just ultra then I'm SOL, I guess.
Is there a way to know what signalling this device uses based just on the connector? I checked all available interent specs, incl the original manual, for the device and *nothing* specifies anything other than "SCSI".
I'm a big SCSI guy, but my memory on the subject is starting to get hazy due to disuse... _______________________________________________ Roundtable mailing list Roundtable@muug.mb.ca http://www.muug.mb.ca/mailman/listinfo/roundtable
This https://en.wikipedia.org/wiki/Parallel_SCSI#Comparison_table might help you narrow it down.
And, quoting Wikipedia:
Interoperability[edit <https://en.wikipedia.org/w/index.php?title=SCSI_connector&action=edit§ion=10>]There are adapters between most types of parallel SCSI connector, and some companies will manufacture custom cables to guarantee having the correct connectors. An adapter from narrow to wide must include termination to work properly.
Different SCSI standards use the same SCSI connectors as in HVD and LVD SCSI (High Voltage Differential and Low Voltage Differential) . HVD uses 15V while LVD uses 3.3V, so connecting an HVD device to an LVD host bus adaptor can blow the line drivers on the HBA, likewise an HVD HBA connected to an LVD device.
Similarly, connecting a (slow) SE single-ended device onto a (fast) LVD SCSI chain will cause the HBA to sync down to the lowest speed.
While interconnectivity of a number of devices may look straightforward, there are many pitfalls, and with older SE devices the cabling length becomes an issue as signal degrades.
-Adam
On 07/03/2015 04:17 PM, Adam Thompson wrote:
Not 100% sure either, but IIRC LVDS (and just plain differential) never had its own connector. With the advent of ... Ultra160??? everything was lvds anyway. I recall a small handful of devices that could do differential or regular based on a jumper or dip switch, over the same connector. What's the device? -Adam
On July 3, 2015 4:06:19 PM CDT, Trevor Cordes trevor@tecnopolis.ca wrote:
I have an external SCSI device that I'd like to plug in on a 10-15' cable. The device has a standard dense 50-pin 2-row connector. I thought at first that meant for sure LVD, but now I'm thinking it just means ultra. I need LVD to get over 1.5M cable length, according to spec. LVD lets me go to 12M it appears. If it's just ultra then I'm SOL, I guess. Is there a way to know what signalling this device uses based just on the connector? I checked all available interent specs, incl the original manual, for the device and *nothing* specifies anything other than "SCSI". I'm a big SCSI guy, but my memory on the subject is starting to get hazy due to disuse... ------------------------------------------------------------------------ Roundtable mailing list Roundtable@muug.mb.ca http://www.muug.mb.ca/mailman/listinfo/roundtable-- Sent from my Android device with K-9 Mail. Please excuse my brevity.
Roundtable mailing list Roundtable@muug.mb.ca http://www.muug.mb.ca/mailman/listinfo/roundtable
I'm a big SCSI guy, but ...
I too am an old SCSI fan, but my interest started to wane when so many SCSI signalling standards and connectors began to proliferate together with SCSI moving totally into the high-end server realm and away from "ordinary" peripherals. Oh, and then there was that "termination power" headache (usually selected/deselected by jumpers).
The device has a standard dense 50-pin 2-row connector. I thought at
first that meant for sure LVD, but now I'm thinking it just means ultra.
It doesn't even mean "ultra", let alone HVD/LVD. That connector became the norm during the single-ended classic SCSI 2 generation - to my great chagrin, since the Centronics 50-pin connector was so much better.
Is there a way to know what signalling this device uses based just on the
connector?
No, but:
I checked all available interent specs, incl the original manual, for the
device and *nothing* specifies anything other than "SCSI".
Since the original manual (lucky you to have that!) doesn't specify anything other than "SCSI", it is a near certainty that this isn't LVD or HVD, but simply good old single-ended classic SCSI (of at least SCSI 2 generation). It probably isn't "ultra" either, especially if it's a scanner or CD drive or similar slow device rather than a hard drive.
Hartmut W Sager - Tel +1-204-339-8331, +1-204-515-1701, +1-204-515-1700
On 3 July 2015 at 16:06, Trevor Cordes trevor@tecnopolis.ca wrote:
I have an external SCSI device that I'd like to plug in on a 10-15' cable. The device has a standard dense 50-pin 2-row connector. I thought at first that meant for sure LVD, but now I'm thinking it just means ultra. I need LVD to get over 1.5M cable length, according to spec. LVD lets me go to 12M it appears. If it's just ultra then I'm SOL, I guess.
Is there a way to know what signalling this device uses based just on the connector? I checked all available interent specs, incl the original manual, for the device and *nothing* specifies anything other than "SCSI".
I'm a big SCSI guy, but my memory on the subject is starting to get hazy due to disuse... _______________________________________________ Roundtable mailing list Roundtable@muug.mb.ca http://www.muug.mb.ca/mailman/listinfo/roundtable
Oh, I also forgot to ask: Which museum relinquished this device? :)
Hartmut W Sager - Tel +1-204-339-8331, +1-204-515-1701, +1-204-515-1700
On 3 July 2015 at 19:48, Hartmut W Sager hwsager@marityme.net wrote:
I'm a big SCSI guy, but ...
I too am an old SCSI fan, but my interest started to wane when so many SCSI signalling standards and connectors began to proliferate together with SCSI moving totally into the high-end server realm and away from "ordinary" peripherals. Oh, and then there was that "termination power" headache (usually selected/deselected by jumpers).
The device has a standard dense 50-pin 2-row connector. I thought at
first that meant for sure LVD, but now I'm thinking it just means ultra.
It doesn't even mean "ultra", let alone HVD/LVD. That connector became the norm during the single-ended classic SCSI 2 generation - to my great chagrin, since the Centronics 50-pin connector was so much better.
Is there a way to know what signalling this device uses based just on
the connector?
No, but:
I checked all available interent specs, incl the original manual, for
the device and *nothing* specifies anything other than "SCSI".
Since the original manual (lucky you to have that!) doesn't specify anything other than "SCSI", it is a near certainty that this isn't LVD or HVD, but simply good old single-ended classic SCSI (of at least SCSI 2 generation). It probably isn't "ultra" either, especially if it's a scanner or CD drive or similar slow device rather than a hard drive.
Hartmut W Sager - Tel +1-204-339-8331, +1-204-515-1701, +1-204-515-1700
On 3 July 2015 at 16:06, Trevor Cordes trevor@tecnopolis.ca wrote:
I have an external SCSI device that I'd like to plug in on a 10-15' cable. The device has a standard dense 50-pin 2-row connector. I thought at first that meant for sure LVD, but now I'm thinking it just means ultra. I need LVD to get over 1.5M cable length, according to spec. LVD lets me go to 12M it appears. If it's just ultra then I'm SOL, I guess.
Is there a way to know what signalling this device uses based just on the connector? I checked all available interent specs, incl the original manual, for the device and *nothing* specifies anything other than "SCSI".
I'm a big SCSI guy, but my memory on the subject is starting to get hazy due to disuse... _______________________________________________ Roundtable mailing list Roundtable@muug.mb.ca http://www.muug.mb.ca/mailman/listinfo/roundtable
Two of the most famous single-ended classic SCSI-2 host adapters of that era, using this 50-pin dense connector, were the Adaptec AHA-2920 non-bus-mastering series and the Adaptec AHA-2940 bus-mastering series, for PCI slot motherboards. They also sported an internal 50-pin 2-row ribbon connector for internal SCSI drives (and a 34-pin 2-row ribbon connector for floppy drives in the case of the AHA-2922 and AHA-2942, I think).
You could actually have both internal and external devices on the single SCSI chain (card in the middle), as long as you disabled the terminating resistor pack on the card itself. You then had to be especially careful in deciding which card/device would supply the terminating resistor power. I recall that Fujitsu hard drives were exceptionally problematic in these configurations.
I presume you (Trevor) know all about having to set each SCSI drive/device, including the host adapter, to a unique SCSI ID, yes?
Life with SATA and USB really is more pleasant.
Hartmut W Sager - Tel +1-204-339-8331, +1-204-515-1701, +1-204-515-1700
On 3 July 2015 at 19:48, Hartmut W Sager hwsager@marityme.net wrote:
I'm a big SCSI guy, but ...
I too am an old SCSI fan, but my interest started to wane when so many SCSI signalling standards and connectors began to proliferate together with SCSI moving totally into the high-end server realm and away from "ordinary" peripherals. Oh, and then there was that "termination power" headache (usually selected/deselected by jumpers).
The device has a standard dense 50-pin 2-row connector. I thought at
first that meant for sure LVD, but now I'm thinking it just means ultra.
It doesn't even mean "ultra", let alone HVD/LVD. That connector became the norm during the single-ended classic SCSI 2 generation - to my great chagrin, since the Centronics 50-pin connector was so much better.
Is there a way to know what signalling this device uses based just on
the connector?
No, but:
I checked all available interent specs, incl the original manual, for
the device and *nothing* specifies anything other than "SCSI".
Since the original manual (lucky you to have that!) doesn't specify anything other than "SCSI", it is a near certainty that this isn't LVD or HVD, but simply good old single-ended classic SCSI (of at least SCSI 2 generation). It probably isn't "ultra" either, especially if it's a scanner or CD drive or similar slow device rather than a hard drive.
Hartmut W Sager - Tel +1-204-339-8331, +1-204-515-1701, +1-204-515-1700
On 3 July 2015 at 16:06, Trevor Cordes trevor@tecnopolis.ca wrote:
I have an external SCSI device that I'd like to plug in on a 10-15' cable. The device has a standard dense 50-pin 2-row connector. I thought at first that meant for sure LVD, but now I'm thinking it just means ultra. I need LVD to get over 1.5M cable length, according to spec. LVD lets me go to 12M it appears. If it's just ultra then I'm SOL, I guess.
Is there a way to know what signalling this device uses based just on the connector? I checked all available interent specs, incl the original manual, for the device and *nothing* specifies anything other than "SCSI".
I'm a big SCSI guy, but my memory on the subject is starting to get hazy due to disuse... _______________________________________________ Roundtable mailing list Roundtable@muug.mb.ca http://www.muug.mb.ca/mailman/listinfo/roundtable
Oops, I may have gotten something wrong. Web information suggests that the AHA-2920 series cards are also bus-mastering, in which case, I can't remember what's different between AHA-2920 and AHA-2940. But I do remember that I used a lot of AHA-2940 series cards.
Hartmut W Sager - Tel +1-204-339-8331, +1-204-515-1701, +1-204-515-1700
On 3 July 2015 at 21:16, Hartmut W Sager hwsager@marityme.net wrote:
Two of the most famous single-ended classic SCSI-2 host adapters of that era, using this 50-pin dense connector, were the Adaptec AHA-2920 non-bus-mastering series and the Adaptec AHA-2940 bus-mastering series, for PCI slot motherboards. They also sported an internal 50-pin 2-row ribbon connector for internal SCSI drives (and a 34-pin 2-row ribbon connector for floppy drives in the case of the AHA-2922 and AHA-2942, I think).
You could actually have both internal and external devices on the single SCSI chain (card in the middle), as long as you disabled the terminating resistor pack on the card itself. You then had to be especially careful in deciding which card/device would supply the terminating resistor power. I recall that Fujitsu hard drives were exceptionally problematic in these configurations.
I presume you (Trevor) know all about having to set each SCSI drive/device, including the host adapter, to a unique SCSI ID, yes?
Life with SATA and USB really is more pleasant.
Hartmut W Sager - Tel +1-204-339-8331, +1-204-515-1701, +1-204-515-1700
On 3 July 2015 at 19:48, Hartmut W Sager hwsager@marityme.net wrote:
I'm a big SCSI guy, but ...
I too am an old SCSI fan, but my interest started to wane when so many SCSI signalling standards and connectors began to proliferate together with SCSI moving totally into the high-end server realm and away from "ordinary" peripherals. Oh, and then there was that "termination power" headache (usually selected/deselected by jumpers).
The device has a standard dense 50-pin 2-row connector. I thought at
first that meant for sure LVD, but now I'm thinking it just means ultra.
It doesn't even mean "ultra", let alone HVD/LVD. That connector became the norm during the single-ended classic SCSI 2 generation - to my great chagrin, since the Centronics 50-pin connector was so much better.
Is there a way to know what signalling this device uses based just on
the connector?
No, but:
I checked all available interent specs, incl the original manual, for
the device and *nothing* specifies anything other than "SCSI".
Since the original manual (lucky you to have that!) doesn't specify anything other than "SCSI", it is a near certainty that this isn't LVD or HVD, but simply good old single-ended classic SCSI (of at least SCSI 2 generation). It probably isn't "ultra" either, especially if it's a scanner or CD drive or similar slow device rather than a hard drive.
Hartmut W Sager - Tel +1-204-339-8331, +1-204-515-1701, +1-204-515-1700
On 3 July 2015 at 16:06, Trevor Cordes trevor@tecnopolis.ca wrote:
I have an external SCSI device that I'd like to plug in on a 10-15' cable. The device has a standard dense 50-pin 2-row connector. I thought at first that meant for sure LVD, but now I'm thinking it just means ultra. I need LVD to get over 1.5M cable length, according to spec. LVD lets me go to 12M it appears. If it's just ultra then I'm SOL, I guess.
Is there a way to know what signalling this device uses based just on the connector? I checked all available interent specs, incl the original manual, for the device and *nothing* specifies anything other than "SCSI".
I'm a big SCSI guy, but my memory on the subject is starting to get hazy due to disuse... _______________________________________________ Roundtable mailing list Roundtable@muug.mb.ca http://www.muug.mb.ca/mailman/listinfo/roundtable
IIRC the xx4x were bootable, the xx2x were not. I don't recall what other differences there were, but the 2920 had a dramatically simpler PCB. -Adam
On July 3, 2015 9:28:26 PM CDT, Hartmut W Sager hwsager@marityme.net wrote:
Oops, I may have gotten something wrong. Web information suggests that the AHA-2920 series cards are also bus-mastering, in which case, I can't remember what's different between AHA-2920 and AHA-2940. But I do remember that I used a lot of AHA-2940 series cards.
Hartmut W Sager - Tel +1-204-339-8331, +1-204-515-1701, +1-204-515-1700
On 3 July 2015 at 21:16, Hartmut W Sager hwsager@marityme.net wrote:
Two of the most famous single-ended classic SCSI-2 host adapters of
that
era, using this 50-pin dense connector, were the Adaptec AHA-2920 non-bus-mastering series and the Adaptec AHA-2940 bus-mastering
series, for
PCI slot motherboards. They also sported an internal 50-pin 2-row
ribbon
connector for internal SCSI drives (and a 34-pin 2-row ribbon
connector for
floppy drives in the case of the AHA-2922 and AHA-2942, I think).
You could actually have both internal and external devices on the
single
SCSI chain (card in the middle), as long as you disabled the
terminating
resistor pack on the card itself. You then had to be especially
careful in
deciding which card/device would supply the terminating resistor
power. I
recall that Fujitsu hard drives were exceptionally problematic in
these
configurations.
I presume you (Trevor) know all about having to set each SCSI drive/device, including the host adapter, to a unique SCSI ID, yes?
Life with SATA and USB really is more pleasant.
Hartmut W Sager - Tel +1-204-339-8331, +1-204-515-1701,
+1-204-515-1700
On 3 July 2015 at 19:48, Hartmut W Sager hwsager@marityme.net
wrote:
I'm a big SCSI guy, but ...
I too am an old SCSI fan, but my interest started to wane when so
many
SCSI signalling standards and connectors began to proliferate
together with
SCSI moving totally into the high-end server realm and away from
"ordinary"
peripherals. Oh, and then there was that "termination power"
headache
(usually selected/deselected by jumpers).
The device has a standard dense 50-pin 2-row connector. I thought
at
first that meant for sure LVD, but now I'm thinking it just means
ultra.
It doesn't even mean "ultra", let alone HVD/LVD. That connector
became
the norm during the single-ended classic SCSI 2 generation - to my
great
chagrin, since the Centronics 50-pin connector was so much better.
Is there a way to know what signalling this device uses based just
on
the connector?
No, but:
I checked all available interent specs, incl the original manual,
for
the device and *nothing* specifies anything other than "SCSI".
Since the original manual (lucky you to have that!) doesn't specify anything other than "SCSI", it is a near certainty that this isn't
LVD or
HVD, but simply good old single-ended classic SCSI (of at least SCSI
2
generation). It probably isn't "ultra" either, especially if it's a scanner or CD drive or similar slow device rather than a hard drive.
Hartmut W Sager - Tel +1-204-339-8331, +1-204-515-1701,
+1-204-515-1700
On 3 July 2015 at 16:06, Trevor Cordes trevor@tecnopolis.ca wrote:
I have an external SCSI device that I'd like to plug in on a 10-15' cable. The device has a standard dense 50-pin 2-row connector. I thought
at
first that meant for sure LVD, but now I'm thinking it just means
ultra.
I need LVD to get over 1.5M cable length, according to spec. LVD
lets me
go to 12M it appears. If it's just ultra then I'm SOL, I guess.
Is there a way to know what signalling this device uses based just
on the
connector? I checked all available interent specs, incl the
original
manual, for the device and *nothing* specifies anything other than "SCSI".
I'm a big SCSI guy, but my memory on the subject is starting to get hazy due to disuse... _______________________________________________ Roundtable mailing list Roundtable@muug.mb.ca http://www.muug.mb.ca/mailman/listinfo/roundtable
Roundtable mailing list Roundtable@muug.mb.ca http://www.muug.mb.ca/mailman/listinfo/roundtable
On 2015-07-03 Hartmut W Sager wrote:
I presume you (Trevor) know all about having to set each SCSI drive/device, including the host adapter, to a unique SCSI ID, yes?
Thanks Adam & Hartmut for all the good info.
Using that and a few more web reads it looks like you're right in that you can't tell squat from the connector. So the device is probably just SE SCSI and I can't do a long cable.
Ya, I know all about SCSI ID's, etc, my main workstation is still running 15k SCSI drives (U320 LVD). At one time I had 9 SCSI devices plugged into my main workstation, but that was a while ago.
I've decided to build a little "outboard computer" with all the myriad parts I have around: it would be about the same size / trouble as an external SCSI case. Even better is it's free. I'll just power it up when I need it and have scripts auto-control it off the lan, then power it down. Cheesy, but it will work.
Life with SATA and USB really is more pleasant.
Yes, I could possibly make things work with a long eSATA setup, but that would cost money for external enclosure, cables, etc. USB can't do what I need because of the intermediary layers.
Oh, I also forgot to ask: Which museum relinquished this device? :)
The Cordes Computer Museum, aka my basement. Tons of SCSI stuff around here!
P.S. from my reading it looks like everything "ultra2" and higher (wide or not) is automatically LVD.
-
Adam Thompson -
Hartmut W Sager -
Trevor Cordes