conductor cable mistery

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J

Jon

I found a missing section on my 80 conductor cable that was connected to my
30GB Westerndigital drive. It was wire number 76 from the pin one position
on the cable and it had a 3 mm section missing. At closer examination under
a microscope showed that the wire was cut with some type of tool as it hads
zagged edges along the sheath and the wire stands all chiseled in the same
direction. With all this stated, do you have an opinion on what this would
allow the drive to do or not do. Could it bypass say encrypted data or make
it compatable with a differant buss technology? Would that missing section
allow someone to gain access to just the boot section, like the master boot
record?

Any ideas on why this would be will be of benefit as this has me puzzled.
Jon
 
Connector pins 37 and 38 are for cable select. Your cut
wire is most likely one of those, or possibly one of the 40
ground wires.
 
Jon said:
I found a missing section on my 80 conductor cable that was connected to my
30GB Westerndigital drive. It was wire number 76 from the pin one position
on the cable and it had a 3 mm section missing. At closer examination under
a microscope showed that the wire was cut with some type of tool as it hads
zagged edges along the sheath and the wire stands all chiseled in the same
direction. With all this stated, do you have an opinion on what this would
allow the drive to do or not do. Could it bypass say encrypted data or make
it compatable with a differant buss technology? Would that missing section
allow someone to gain access to just the boot section, like the master boot
record?

Any ideas on why this would be will be of benefit as this has me puzzled.
Jon
Click to expand...

Pin No.28 (CSEL) is used for cable select. The device connected to the
"master connector" has its CSEL signal grounded through pin No.28.
The other "slave connector" does not have pin No. 28 grounded.

From your statement it's difficult to tell if the cut was in the wire
to pin No. 28. In any event it's not possible for any cable cut to do
any of the things you've mentioned.

Virg Wall
 
I found a missing section on my 80 conductor cable that was connected to my
30GB Westerndigital drive. It was wire number 76 from the pin one position
on the cable and it had a 3 mm section missing. At closer examination under
a microscope showed that the wire was cut with some type of tool as it hads
zagged edges along the sheath and the wire stands all chiseled in the same
direction. With all this stated, do you have an opinion on what this would
allow the drive to do or not do. Could it bypass say encrypted data or make
it compatable with a differant buss technology? Would that missing section
allow someone to gain access to just the boot section, like the master boot
record?

Any ideas on why this would be will be of benefit as this has me puzzled.
Jon
Click to expand...

No, nothing that sinister, it's the cable-select lead.
 
Jon said:
I found a missing section on my 80 conductor cable that was connected to my
30GB Westerndigital drive. It was wire number 76 from the pin one position
on the cable and it had a 3 mm section missing. At closer examination under
a microscope showed that the wire was cut with some type of tool as it hads
zagged edges along the sheath and the wire stands all chiseled in the same
direction. With all this stated, do you have an opinion on what this would
allow the drive to do or not do. Could it bypass say encrypted data or make
it compatable with a differant buss technology? Would that missing section
allow someone to gain access to just the boot section, like the master boot
record?

Any ideas on why this would be will be of benefit as this has me puzzled.
Jon
Click to expand...

..


You are sure it's 76, and only 76?

Conductor 76 is one of the 40 extra grounds that are part of the 80-conductor
cables. All even-numbered conductors are connected to ground inside the
connectors.

It's not cable-select as was suggested by others. Cable-select(CSEL) uses
conductor 55, and connector pin 28.
 
steven67@ said:
.

You are sure it's 76, and only 76?

Conductor 76 is one of the 40 extra grounds that are part of the 80-conductor
cables. All even-numbered conductors are connected to ground inside the
connectors.

It's not cable-select as was suggested by others. Cable-select(CSEL) uses
conductor 55, and connector pin 28.
Click to expand...

I never counted the conductors. I know CSEL is pin 28, as I said. Maybe
whoever was trying to read his encrypted data changed the conductors around? ;-)

Virg Wall
 
in news:[email protected]:
I found a missing section on my 80 conductor cable that was connected
to my 30GB Westerndigital drive. It was wire number 76 from the pin
one position on the cable and it had a 3 mm section missing. At
closer examination under a microscope showed that the wire was cut
with some type of tool as it hads zagged edges along the sheath and
the wire stands all chiseled in the same direction. With all this
stated, do you have an opinion on what this would allow the drive to
do or not do. Could it bypass say encrypted data or make it
compatable with a differant buss technology? Would that missing
section allow someone to gain access to just the boot section, like
the master boot record?

Any ideas on why this would be will be of benefit as this has me
puzzled. Jon
Click to expand...

The 40-pin ribbon cables were ATA-1 to ATA-4 spec. The 80-wire/40-pin
ribbon cables are ATA-5 and ATA-6 spec. http://www.t13.org/ has the
specs (if you can find the link) but they usually want to sell them at
www.ansi.org at $18 apiece.

Pin 1 is still pin 1 (for signal) whether a 40- or 80-wire cable. The
extra 40 ground wires are the even numbered ones that are between the
signal wires which are the odd numbered ones. That's why I have to
wonder if you miscounted the wire with the break. Was it really the 5th
wire from the other side of the 80-wire ribbon cable? If not, the break
is on a ground wire (so reduction of crosstalk might be compromised).
Since the odd wires are the signals that connect to the pins in the
connectors, conductor N (where N is odd) goes to pin (N+1)/2; that is,
wire N = pin (N+1)/2, or alternately pin N = wire 2N-1. If you really
meant wire 75 or 77 then you're talking about pins 37 and 38.

Wire 75 = pin (75+1)/2 = pin 37 = CS1 (Chip Select 1), aka -CS1FX
Wire 76 = ground line
Wire 77 = pin (77+1)/2 = pin 38 = CS3 (Chip Select 3), aka -CS3FX.

I'm no cabling or drive interface wizard. Tis easy 'nuff to just do a
Google search to find references, like http://snurl.com/39wj or
http://snurl.com/39wv. I didn't bother to lookup more detailed articles
that describe the function of each signal, but did glance at
http://www.pcguide.com/ref/hdd/if/ide/confCable80-c.html (the only place
I found that mentions how an old style 40-wire gets detected when an
80-wire cable is required for ATA/66 and higher), http://snurl.com/39wm,
and http://www.t13.org/project/d0948r4c.pdf.

I don't know why other respondents focused on Cable Select (CS) which is
pin 28 or wire (28*2)-1, or wire 55, in an 80-wire cable as Steven67
already pointed out. You'd have to be short by a count of 20 wires to
be looking at cable select. 3mm is too big to be from a tool falling
onto the floor where the cable lay. You mentioned zagged edges along
the other nearby wire which means the 3mm section was pulled out instead
of cut out (cutting would not have left a jagged edge). Sounds more
like the cable got wrapped around something sharp or was damaged but
luckily in a wire that probably won't hurt much regarding functionality
although I don't know in regards to its reduction in crosstalk.
 
Ok. The drive works ok so it must be a ground then. Thaks everyone for you
input. It's just that I've never noticed a section of ribbin missing like
that. Still don't know why it's like that but it doesn't matter now that
you'll have explained what that wire did. Thanks for all your help. Have a
very Merry Holiday.

Jon.
 
From: "Jon" (e-mail address removed)
Date: 12/05/2003 2:34 PM Eastern Standard Time
Message-id: <[email protected]>

Ok. The drive works ok so it must be a ground then. Thaks everyone for you
input. It's just that I've never noticed a section of ribbin missing like
that. Still don't know why it's like that but it doesn't matter now that
you'll have explained what that wire did. Thanks for all your help. Have a
very Merry Holiday.

Jon.
Click to expand...

No, it's NOT a ground, although it is connected to ground in the connector
which plugs into the motherboard, and it's got nothing to do with cable select,
as others have mentioned. Here's the correct explanation:

"Detection: Since the cable is mandatory for high-speed modes, the system has
to have some way of knowing it is installed. This is done by having the
/PDIAG:/CBLID signal, carried on pin #34 of the interface, grounded in the
connector that attaches to the motherboard. Since the older 40-conductor cable
would not have this pin grounded, by looking for the grounding on this pin at
startup the host can determine if the 80-conductor cable is installed."

The above quote is from the following webpage:
www.pcguide.com/ref/hdd/if/ide/confCable80-c.html

The wire is cut near the motherboard end of the cable so that the drives will
not "see" the ground on that pin.

Chris
 
in news:[email protected]:
No, it's NOT a ground, although it is connected to ground in the
connector which plugs into the motherboard, and it's got nothing to
do with cable select, as others have mentioned. Here's the correct
explanation:

"Detection: Since the cable is mandatory for high-speed modes, the
system has to have some way of knowing it is installed. This is done
by having the /PDIAG:/CBLID signal, carried on pin #34 of the
interface, grounded in the connector that attaches to the
motherboard. Since the older 40-conductor cable would not have this
pin grounded, by looking for the grounding on this pin at startup the
host can determine if the 80-conductor cable is installed."

The above quote is from the following webpage:
www.pcguide.com/ref/hdd/if/ide/confCable80-c.html

The wire is cut near the motherboard end of the cable so that the
drives will not "see" the ground on that pin.

Chris
Click to expand...

Guess you missed that Jon said it was *wire* 76. That wire is a ground
wire. All even wires are ground wires. If Jon had been off by one in
his wire count, he was talking about wires 75 and 77 which would be for
pins 38 and 39 (I was off by one myself in my other post), which are
still a ways away from pin 34. Those would be for the -CS3FX
and -DA/SP. So it's likely that Jon was correct in his count of 76 so
it was a ground wire that was cut. Pin 34 (wire 67) is a *signal* line
that gets shorted to ground (I had already mentioned the same PC Guide
article that you did). It isn't a ground wire getting grounded. Reread
the PC Guide article. It says *pin* 34 is grounded. It is a *signal*
wire that is getting grounded.

According to http://snurl.com/39wm to which I also provided the link
before, "PDIAG (passed diagnostics) is a signal used by drive 1 to tell
drive 0 when (and if) it has passed its diagnostics following a power-up
or a reset. Drive 0 uses this information to inform the system of a
drive 1 failure." That's how it *could* be used in the old
40-wire/40-pin setup under ATA-4. There's a lot more gobbelty gook at
another link I listed, http://www.t13.org/project/d0948r4c.pdf, that
goes even more into detail about this signal. Under ATA-5, it became a
CBLID (cable ID) *signal* tied low to indicate the presence of an
80-wire cable. If it isn't shorted to ground (in the mobo end
connector) then it isn't low and even an 80-wire cable with this signal
line as high would get detected as a 40-wire cable.
 
From: "*Vanguard*" (e-mail address removed)
Date: 12/06/2003 2:37 AM Eastern Standard Time
Message-id: <0HfAb.311810$9E1.1563802@attbi_s52>

in news:[email protected]:

Guess you missed that Jon said it was *wire* 76. That wire is a ground
wire. All even wires are ground wires. If Jon had been off by one in
his wire count, he was talking about wires 75 and 77 which would be for
pins 38 and 39 (I was off by one myself in my other post), which are
still a ways away from pin 34. Those would be for the -CS3FX
and -DA/SP. So it's likely that Jon was correct in his count of 76 so
it was a ground wire that was cut. Pin 34 (wire 67) is a *signal* line
that gets shorted to ground (I had already mentioned the same PC Guide
article that you did). It isn't a ground wire getting grounded. Reread
the PC Guide article. It says *pin* 34 is grounded. It is a *signal*
wire that is getting grounded.
Click to expand...



I never said that it was "a ground wire getting grounded". I quoted the article
which said pin 34 is grounded. The stub of that wire remains connected to the
pin, hence, that part of the wire is grounded.
Also, noting that he said wire 76, whereas pin 34 is wire 67. Could that have
been a typo on his part?

The cable in my machine has the same cut he described, about an inch from the
connector, in wire 67.

I did not see your other posts.
 
in news:[email protected]:
I never said that it was "a ground wire getting grounded". I quoted
the article which said pin 34 is grounded. The stub of that wire
remains connected to the pin, hence, that part of the wire is
grounded.
Also, noting that he said wire 76, whereas pin 34 is wire 67. Could
that have been a typo on his part?

The cable in my machine has the same cut he described, about an inch
from the connector, in wire 67.

I did not see your other posts.
Click to expand...

Could be Jon was dyslexic and switched the digits around. The only
reason that I can think that the wire should be cut is maybe pin 34 on
the drive should not be grounded so it is left floating.

Does the cut appear near the end connector for a drive (so the cut is
between the master and slave connectors), or somewhere between the end
connector for the mobo and the middle connector (so pin 34 is floating
for both drives, if both connectors were used)?
 
From: "*Vanguard*" (e-mail address removed)
Date: 12/06/2003 12:35 PM Eastern Standard Time
Message-id: <mroAb.443203$Tr4.1232882@attbi_s03>

in news:[email protected]:

Could be Jon was dyslexic and switched the digits around. The only
reason that I can think that the wire should be cut is maybe pin 34 on
the drive should not be grounded so it is left floating.

Does the cut appear near the end connector for a drive (so the cut is
between the master and slave connectors), or somewhere between the end
connector for the mobo and the middle connector (so pin 34 is floating
for both drives, if both connectors were used)?
Click to expand...

The cut is about 1 inch from the motherboard end of the cable, so pin 34 would
be floating for both drives. (I don't know what the results would be if the
drives saw the pin grounded.)
 
in news:[email protected]:
The cut is about 1 inch from the motherboard end of the cable, so pin
34 would be floating for both drives. (I don't know what the results
would be if the drives saw the pin grounded.)
Click to expand...

I suspect they do that so you could use an 80-wire/40-pin cable as a
[more expensive] substitute for a 40-wire/40-pin cable. The
descriptions of the old use of PCDIAG for pin 34 don't mention if the
line gets pulled high or low when drive 1 (master) reports to drive 0
(slave) that it is okay on startup. Maybe pulled low means bad so they
leave it float (and let drive 0 assume drive 1 always comes up okay).
 
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