🚀 go-pugleaf

Eugen wrote:
> 
> 18" HDD standard?? So what about server towers? Have you seen
> the distance between, say CD-ROM or even HDD to the IDE controller connector on the board?
> My cables in full-tower case are longer than 24" (although they are plain cables, not rounded ones)
> and I never got my data corrupted in that machine. And those cables were not custom-made or
> whatever.

Fine. You got lucky. How do you know you don't have data corruption?
Have you verified every file that you've written since you started using
the long cables?

When a specification says maximum cable length is 18" it means that with
properly designed interfaces at both ends of the cable, running under
worst-case conditions, things are guaranteed to meet the maximum error
rate in the specification. Now I haven't read the ATA-100 spec so I'm
taking Strider's word that 18" max is the spec.

Will it work with longer cables most of the time? Almost certainly. Is
it guaranteed? Absolutely not. Is there a possibility of data corruption
with longer cables? Absolutely. 

You can say as many times as you want that "It works fine for me" but
that doesn't change the underlying physics of the situation. If you are
comfortable with the risk, then go for it. If you value your data, then
don't do it.


A further note is that the specification was designed with flat cables
in mind. Now it turns out that however cheap flat cables look they are
electrically very effective, when kept flat. When you roll up a flat
cable, as some rounded cables do, you change things about the physics of
the cable and none of the changes are good. First, you bring one or more
of the signal wires close to other ground wires which changes the
impedance of that wire. This can cause reflections on the cable. Second,
you bring one or more of the signal wires close to other signal wires
which causes undesired coupling between them.

So combine the potential problems caused by longer cables with the
potential problems caused by rolling up the flat cable and you have 2
good reasons not to use rounded cables.

> "Strider" <not@here.invalid> wrote in message news:uefvu7m1lgks7e@corp.supernews.com...
> >
> > "chili" <chilihead@onlink.net> wrote in message
> > news:ac7uv5$aia$1@onlink3.onlink.net...
> > > I have been using them now for about a year and have not had any "data
> > > corruption" or at least noticeably, and they do look cool. I have blue for
> > > my hard drives, green for my writers and dark red for my floppies. Looks
> > > real "tekie." :)
> > >
> > > chili
> >
> > Well, maybe you haven't but it has been shown that they are less reliable
> > than standard ribbon cables. Also the ones he is advertisig are 24" which is
> > over the 18" recommended spec for HD's, which can alo lead to data
> > corruption. 'You takes your chances'. I don't.
-- 
Tim Hubberstey, P.Eng. . . . . . Hardware/Software Consulting Engineer
Marmot Engineering . . . . . . .  VHDL, ASICs, FPGAs, embedded systems