Trying to identify SCSI cables

At my office, we have a bunch of long SCSI cables with HD68
connectors. They were manufactured by Advanced Cable Tech in Hudson,
MA, and resold by EMC. The cables are labelled (with what I assume is
an EMC part number) as follows:
038-001-254
37895.01A Rev A
ACT 634
"GENE 19M"

If anyone can give me a good description of what these are, I would
appreciate it.

Eric M. Berg
)

(Eric M. Berg) wrote in
m:
At my office, we have a bunch of long SCSI cables with HD68
connectors.

If they're long (more than 6 ft or so) there's a 95% chance they're diff -
HVD - cables.


--
/Jesper Monsted

On 4 Dec 2003 22:00:28 -0800, (Eric M. Berg)
wrote:

At my office, we have a bunch of long SCSI cables with HD68
connectors. They were manufactured by Advanced Cable Tech in Hudson,
MA, and resold by EMC. The cables are labelled (with what I assume is
an EMC part number) as follows:
038-001-254
37895.01A Rev A
ACT 634
"GENE 19M"

If anyone can give me a good description of what these are, I would
appreciate it.

At a guess, 19 meter SCSI cables?

Obviously, that means they would have been used with HVD SCSI, and the
length suggests that they were host-disk array connections.

They'll work with any (high voltage) differential device.

Eric M. Berg
)

Malc.

"Malcolm Weir" wrote in message ...
On 4 Dec 2003 22:00:28 -0800, (Eric M. Berg)
wrote:

At my office, we have a bunch of long SCSI cables with HD68
connectors. They were manufactured by Advanced Cable Tech in Hudson,
MA, and resold by EMC. The cables are labelled (with what I assume is
an EMC part number) as follows:
038-001-254
37895.01A Rev A
ACT 634
"GENE 19M"

If anyone can give me a good description of what these are, I would
appreciate it.

At a guess, 19 meter SCSI cables?

Obviously, that means they would have been used with HVD SCSI, and the
length suggests that they were host-disk array connections.


They'll work with any (high voltage) differential device.

Yes, can't possibly work with LVD devices, can it. The cable would know.


Eric M. Berg
)

Malc.

"Jesper Monsted" wrote in message 4.163...
(Eric M. Berg) wrote in m:
At my office, we have a bunch of long SCSI cables with HD68 connectors.

If they're long (more than 6 ft or so) there's a 95% chance they're diff -
HVD - cables.

The limit for Fast SCSI is 10ft.
So, if I were you, I wouldn't place bets on that.



--
/Jesper Monsted

On Sat, 6 Dec 2003 00:48:44 +0100, "Folkert Rienstra"
wrote:


"Jesper Monsted" wrote in message 4.163...
(Eric M. Berg) wrote in m:
At my office, we have a bunch of long SCSI cables with HD68 connectors.

If they're long (more than 6 ft or so) there's a 95% chance they're diff -
HVD - cables.

The limit for Fast SCSI is 10ft.
So, if I were you, I wouldn't place bets on that.

No, it's 25 Meters.

Malc.

"Malcolm Weir" wrote in message ...
On Sat, 6 Dec 2003 00:48:44 +0100, "Folkert Rienstra" wrote:

"Jesper Monsted" wrote in message 4.163...
(Eric M. Berg) wrote in m:
At my office, we have a bunch of long SCSI cables with HD68 connectors.

If they're long (more than 6 ft or so) there's a 95% chance they're diff -
HVD - cables.

The limit for Fast SCSI is 10ft.
So, if I were you, I wouldn't place bets on that.

No, it's 25 Meters.

Absolutely clueless.


Malc.

On Tue, 9 Dec 2003 00:12:34 +0100, "Folkert Rienstra"
wrote:


"Malcolm Weir" wrote in message ...
On Sat, 6 Dec 2003 00:48:44 +0100, "Folkert Rienstra" wrote:

"Jesper Monsted" wrote in message 4.163...
(Eric M. Berg) wrote in m:
At my office, we have a bunch of long SCSI cables with HD68 connectors.

If they're long (more than 6 ft or so) there's a 95% chance they're diff -
HVD - cables.

The limit for Fast SCSI is 10ft.
So, if I were you, I wouldn't place bets on that.

No, it's 25 Meters.

Absolutely clueless.

Oh, dear. Oh dear, oh dear, oh dear.

Do you KNOW what HVD means?

Before you go around calling people "clueless", perhaps, Folkert
Rienstra, you should have a clue yourself.

The particular clue you should have is in section 5.1 of X3.131-1994,
which is the designation given to revision 10L of draft X3T9 ANSI
standard better known as SCSI-2 when it was approved by the American
National Standards Institute's Board of Standards Review on January
31, 1994.

I.e. the damn spec, Folkert Rienstra.

For your edification, here's that section:

[ Begin ]
5.1 Physical description
SCSI devices are daisy-chained together using a common 50-conductor A
cable and, optionally, a 68-conductor B cable. Both ends of each cable
are terminated. All signals are common between all SCSI devices on the
A cable. In systems that employ the wide SCSI option, wide SCSI
devices additionally connect to the B cable. Various width SCSI
devices may be mixed.

NOTE 1 An alternate 16-bit single-cable solution and an alternate
32-bit solution is being defined and the B cable definition will be
removed in a future version of SCSI.

Two driver/receiver alternatives are specified:

a) Single-ended drivers and receivers, which allow a maximum cable
length of 6 m (primarily for connection within an enclosure).
b) Differential drivers and receivers, which allow a maximum cable
length of 25 m.
The single-ended and differential alternatives are mutually exclusive
on the same physical bus.

NOTE 2 Use of single-ended drivers and receivers with the fast
synchronous data transfer option is not recommended.
[End]

That paragraph "b" is the bit that should be causing you embarrassment
right about now, Folkert.

By the way, note that the people who wrote the damn spec recommend
*against* using single-ended Fast SCSI, which makes your initial
mis-statement even more ironic! And even if you do, you'll see that
the single-ended max length is 6m, or about 18ft, not the "10ft" that
you claim.

Feel free to apologize any time you like!

Malc.

"Folkert Rienstra" wrote in
:
They'll work with any (high voltage) differential device.

Yes, can't possibly work with LVD devices, can it. The cable would
know.

Since LVD doesn't allow cable lengths of 19 meters, no, it wouldn't.


--
/Jesper Monsted

"Malcolm Weir" wrote in message
On Tue, 9 Dec 2003 00:12:34 +0100, "Folkert Rienstra" wrote:

"Malcolm Weir" wrote in message ...
On Sat, 6 Dec 2003 00:48:44 +0100, "Folkert Rienstra" wrote:

"Jesper Monsted" lid wrote in message 4.163...
(Eric M. Berg) wrote in m:
At my office, we have a bunch of long SCSI cables with HD68 connectors.

If they're long (more than 6 ft or so) there's a 95% chance they're diff -
HVD - cables.

The limit for Fast SCSI is 10ft.
So, if I were you, I wouldn't place bets on that.

No, it's 25 Meters.

Absolutely clueless.

Oh, dear. Oh dear, oh dear, oh dear.

Do you KNOW what HVD means?

Yes Malcolm, you know I do.


Before you go around calling people "clueless", perhaps, Folkert
Rienstra, you should have a clue yourself.

I have a 4 year existence in this newsgroup that says that I do, Malcolm.


The particular clue you should have is in section 5.1 of X3.131-1994,
which is the designation given to revision 10L of draft X3T9 ANSI
standard better known as SCSI-2 when it was approved by the American
National Standards Institute's Board of Standards Review on January
31, 1994.

Isn't that that experimental standard that was never finished and was
overtaken by the SCSI-3 standard, Malcolm?


I.e. the damn spec, Folkert Rienstra.

A draft, actually. An experimental and never finished spec, Malcolm.


For your edification, here's that section:

[ Begin ]
5.1 Physical description
SCSI devices are daisy-chained together using a common 50-conductor A
cable and,

optionally, a 68-conductor B cable.

Which shows the experimental stage of that spec, doesn't it, Malcolm.

Both ends of each cable are terminated. All signals are common between
all SCSI devices on the A cable. In systems that employ the wide SCSI
option, wide SCSI devices additionally connect to the B cable. Various
width SCSI devices may be mixed.

For your edification, Malcolm, that means both A and B cables connect
to a wide device. You ever seen one of those, have you?


NOTE 1 An alternate 16-bit single-cable solution and an alternate
32-bit solution is being defined and the B cable definition will be
removed in a future version of SCSI.

Which in practice happened much sooner and may or may not have
found it's way in the final SCSI-2 spec that isn't available for free.


Two driver/receiver alternatives are specified:

a) Single-ended drivers and receivers, which allow a maximum cable
length of 6 m (primarily for connection within an enclosure).

Not for Fast SCSI, that is (Fast-10).

b) Differential drivers and receivers, which allow a maximum cable
length of 25 m.
The single-ended and differential alternatives are mutually exclusive
on the same physical bus.

NOTE 2 Use of single-ended drivers and receivers with the fast
synchronous data transfer option is not recommended.

Well, that again really shows how much behind (or incomplete) that draft
was. Not only did Fast SCSI use SE drivers, Ultra SCSI (SCSI-3) after
that did use SE drivers. What changed was the use of active negation
drivers in SCSI-3.

The 6 meter limit is for Asynchronous SCSI (Fast-5).

[End]

That paragraph "b" is the bit that should be causing you embarrassment
right about now, Folkert.

Not any more than it should do you on paragraph a), Malcolm.


By the way, note that the people who wrote the damn spec recommend
*against* using single-ended Fast SCSI, which makes your initial
mis-statement even more ironic!

Or your's moronic, Malcolm.
Notice that "Fast SCSI", Malcolm? As opposed to Asynchronous SCSI?

And even if you do, you'll see that the single-ended max length is 6m,
or about 18ft, not the "10ft" that you claim.

That's for async, Malcolm, not synchronous Fast-10, better known as Fast SCSI.
Go see the SCSI-3 drafts, which build on the SCSI-2 spec and should there-
for be closer to the final SCSI-2 spec than that SCSI-2 draft ever came.

You do of course know where to find the SCSI-3 drafts, don't you, Malcolm?


Feel free to apologize any time you like!

Likewise, Malcolm.
My statement may have been overgeneralized, but so was yours.
Worse is that you don't seem to have grasped what SCSI is all about.


Malc.