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Old November 15th 06, 06:39 AM posted to alt.comp.hardware
Rod Speed
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Default SATA data cable - pin query

Paul wrote:
Rod Speed wrote:
wrote:

Further to the issues I have been having with a broken SATA
data connector (which still works after being wedged on!)
I was wondering about the pin arrangement on the
connector. I note there are 2 transmit and 2 receive pins


Each pair is a balanced pair, like with a twisted pair in a cable.

with 3 ground pins...


My question is - what if one or more of the ground
pins were not connected, would the drive still work


Yes.

and if so is it dangerous?


Nope.

i.e. must ALL 7 pins be connected before the drive will work/be
seen by XP?


The 4 data lines are crucial, not all the ground lines are.



http://www.sata-io.org/docs/serialat...chnology.p df

"Serial ATA – 4-wire cable with support for optional shield / drain
wires
Serial ATA uses a minimum 4-wire cable that includes differential
pairs for transmitting and receiving data. To minimize impedance
and crosstalk, many cables incorporate additional shielding ground
drain lines which function similarly to the 40 interspersed ground
lines in the 80-pin Ultra ATA cable. The Serial ATA connector
supports 3 independent ground return paths. Serial ATA cables are
specified to be at max 1m in length."


If I had to choose a ground pin to break off, I'd want to choose one of the outside ground pins,
and not the one in the center.


I doubt it would make much difference in practice.

And its certainly not dangerous in the sense of killing anything.