Max IDE Cable Length?

[Kevin Buettner]

On May 6, 10:25am, Fritz wrote:

> I purchased some of those new-fangled "round" IDE
> cables the other day.  They're much easier to work with
> and they probably do allow better air flow in the cabinet.
> 
> These cables are 24" long.  I was under the impression
> that the IDE Spec limited cables to 18".  The salesman
> said "I'm sure that they're OK, otherwise no one would
> be making them and we wouldn't be selling them".
> Well, with logic like that I promptly opened my wallet
> and ....
> 
> Has it got anything to do with the old ATA/33/66 vs. the
> new ATA/100/133?  Or the old 40 conductor vs. the new
> 80 conductor?  Anyone have any clues about this?
> 
> The system *seems* to work fine.  Perhaps, my data is
> quietly being corrupted, bit by bit ............ :-(

Google came up with this:

    http://www.onstream.com/knowledge/kb-art-1042.shtml

So your recollection of 18" seems right.

But, also see:

    http://www.lostcircuits.com/advice/atafaq/

In particular, here's a quote from the the lostcircuits document:

    ATA66 or higher was defined to use a 80 wire flat ribbon cable
    (0,635mm between wires) with a maximal length of 45cm and up to 3
    connectors (blue for controller, black for slave and master). 
    Longer ribbon cable can be used if the slave connector is omitted
    as can be seen with 3ware IDE-RAID-Adapter that come with a 60cm
    long UDMA cable.  While this is in violation to the specifications
    it seems to work flawlessly since the disturbance on the
    transmission line caused by the slave drive connector in the
    middle is deleted [3].

You should read more of the lostcircuits article to see what they
have to say about rounded IDE cables...

Kevin