TechSpot

Shortening ATA/66+ cables

By Per Hansson
Oct 18, 2002
  1. I few weeks ago I tried cutting of my ATA cables removing the "mobo" end, but to my suprise the cable didn't work, or rather it was detected as an 40 conductor instead of 80 conductor cable...

    The reason for this is that the "mobo end" of the cable is the only end that has the ground wires connected in the terminal, so what I did was actually removing the cables grouding function which is the only addition to ATA66+:blush:

    So if you want to shorten your ATA 66+ cables to remove clutter in your case for example you must keep the "mobo end" and cut off the "master end" leaving you with the longer of the two cables, but atleast it will be shorter than when you started and still have it's 80 conductors all connected...

    I'll include the mails I sent to Mike who helped me solve this (read from bottom to top)

    --------------

    Hi Mike, I found a site that sells custom cut cables:

    http://www.cgicomputerwares.com/index_50.htm

    What I want to do is remove the clutter from the IDE
    cables in my case (as I said 15cm long cables are more
    than enough...)

    And no, I wont mind if you mention our finding, just
    put a small link to Techspot.com there ;-)

    I searched a while for the ATA spec but only came up
    with that the name of a file describing it is:
    "SFF-8049.PDF" (gives one hit on google which itself
    links to a dead FTP server :(

    Sincerely - Per Hansson, editor @ Techspot.com
    ---------------------------------------------------
    --- Michael Schuette <michael.schuette@edram.com>
    wrote:
    > P.s. Do you mind if I use your finding to update
    > the articles in question (IBM vs. Maxtor and SATA)?
    >
    > Best Regards
    >
    > Michael
    >
    > -----Original Message-----
    > From: Per Hansson [mailto:]
    > Sent: Wednesday, October 09, 2002 9:00 AM
    > To: Michael Schuette
    > Subject: RE: Cutting a ATA-66 cable (second mail)
    >
    >
    > Hi again Mike, I've found out that you infact where
    > right, it's only the "mobo" end of the ATA cable
    > that
    > has the ground wires attached...
    >
    > And this must also be why you must connect the cable
    > in the right direction, i.e. otherwise the ground
    > cables will not be grounded...
    >
    > So, now is how do we overcome this?
    >
    > Do you know if any retailer sell "custom cut" ATA
    > cables, or if any of the manufacturers connect the
    > ground cables in all terminals in the ATA cable?
    >
    > Sincerely - Per Hansson, editor @ Techspot.com
    > ------------------------------------------------
    > --- Michael Schuette <michael.schuette@edram.com>
    > wrote:
    > > Per,
    > >
    > > Thanks for that tip. Usually, there should be no
    > > difference whether you cut it off or not unless
    > the
    > > shield wires are only connected to ground in the
    > two
    > > terminal connectors. This could vary from one
    > > manufacturer to another, meaning that there is a
    > > chance that the center connector only does a
    > > pass-through for the ground. In this case, the
    > > controller would not see the correct resistance
    > > value for the combined ground and default to UDMA
    > > because electrically it would be looking at a 4
    > wire
    > > cable. Very interesting..
    > >
    > > DUH, I just reread what you did and there is
    > > actually a possibiity that the only connector that
    > > has the ground -to-shield connections internally
    > is
    > > the blue connector that goes on the mobo. In fact,
    > > that is the only one that would be needed.
    > >
    > > Of course, that would not influence the basic
    > > fonctionality of the drives, they are 100 %
    > backward compatible with
    > > the older standards but then they would work in
    > UDMA mode only.
    > >
    > > Best Regards
    > >
    > > Michael
    > >
    > > -----Original Message-----
    > > From: Per Hansson [mailto:]
    > > Sent: Monday, October 07, 2002 11:05 AM
    > > To: ms@lostcircuits.com
    > > Subject: Cutting a ATA-66 cable
    > >
    > >
    > > Hi there Mike, read your very fine artcile on
    > Serial
    > > ATA awhile back and also posted a small link to it
    > > over at Techspot.com
    > >
    > > In that article you say that while one can't place
    > a
    > > single unit in the middle of the ATA cable you can
    > > cut
    > > it off and it should work...
    > >
    > > I thought then that fine, if it's ok to cut off
    > the
    > > small end (i.e. Master end) it should be fine to
    > cut
    > > of the long end (i.e. the mobo end) however when I
    > > did
    > > so the mainboard identifies the cable as a
    > > 40-conductor cable and thus reverts down to ATA-33
    > > mode...
    > >
    > > I only need the short end of the cable because I
    > > have
    > > a Lian LI case with the drive cage on the bottom
    > and
    > > IDE RAID connectors at the bottom at the mobo, so
    > > the
    > > 15CM the cables become when cut off is more than
    > > enough...
    > >
    > > So my question to you is why does the mainboard
    > > identify the cable as 40 conductor...
    > >
    > > I may aswell list the relevant specs, the
    > mainbaord
    > > is
    > > Epox's 8K3A+ and I'm using as I said it's onboard
    > > RAID controller (however the same happens if I
    > > connect it to the "usual" ATAPI connectors on the
    > > mobo to
    > > though...)
    > >
    > > The harddrives are two Maxtor D740X with fluid
    > > bearings...
    > >
    > > A small side note is that while the drives did
    > work
    > > at
    > > ATA-33 there where no problems, they just didn't
    > > work
    > > as fast as before...
    > >
    > > Sincerely - Per Hansson, editor @ Techspot.com
     
  2. lludacrisboy

    lludacrisboy TS Rookie Posts: 32

    thats pretty wild. i didnt know that about the IDe cables motherboard end. everyones going sata but thats something i never knew thank you for letting us know.
     
  3. Mictlantecuhtli

    Mictlantecuhtli TS Evangelist Posts: 4,916   +9

    The PDF links here seem to work.
     
  4. SNGX1275

    SNGX1275 TS Forces Special Posts: 12,623   +320

    Did you go to the very last page of this forum and find threads to reply to? This is the 2nd thread I've seen that is 5 years old that you've brought back.
     
  5. poertner_1274

    poertner_1274 secroF laicepS topShceT Posts: 4,745

    Confused as well *shrug*
     
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