You may be thinking of differential SCSI which uses a balanced (and twisted) pair for each data and signal line. In the old days, there was only one flavor of differential, and it was popular at least on Hewlett-Packard 800 series systems (which uses round SCSI cables). Now, in addition to the old differential, there is something called "low voltage differential" (LVD) also known in marketing hype as "Ultra2". LVD cables look like a "ribbon" cable but have the signal pairs twisted. The last ones I bought from Adaptec were high quality, but expensive! Best I remember, they were almost $100 for a 4 device cable. But then again, they have active terminators built on the end of the cable (LVD drives don't have built-in terminators).
-----Original Message-----
From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED]]
Sent: Tuesday, January 11, 2000 10:11 PM
To: [EMAIL PROTECTED]
Cc: [EMAIL PROTECTED]; [EMAIL PROTECTED]
Subject: Re: Ribbon Cabling (was Re: large ide raid system)
> From [EMAIL PROTECTED] Tue Jan 11 21:44:29 2000
>
> On Tue, 11 Jan 2000, Gregory Leblanc wrote:
> > If you cut the cable
> > lengthwise (no, don't cut the wires) between wires (don't break the
> > insulation on the wires themselves, just the connecting plastic) you can
> > get your cables to be 1/4 the normal width (up until you get to the
> > connector).
>
> I don't know about IDE, but I'm pretty sure that's a big no-no for SCSI
> cables. The alternating conductors in the ribbon cable are sig, gnd, sig,
> gnd, sig, etc. And it's electrically important (for proper impedance and
> noise and cross-talk rejection) that they stay that way.
>
> I think the same is probably true for the schmancy UDMA66 cables too...
<vent>
Back in the day.... 8-) ....high end SCSI ribbon cables consisted of
twisted pairs between the connectors so it was really easy to deform
the cable to fit through tight spots. Now, all I seem to find is the
cheap ribbon cable that's excreted from nameless companies in developing
countries where their ideas of quality control differ vastly from
mine. 8-) Either I'm really unlucky or the quality of ribbon cabling
in general is in decline...sigh.
</vent>
And I agree with the idea that slicing up the ribbon cable is probably
not going to work.
Cheers,
Chris
--
Christopher Mauritz
[EMAIL PROTECTED]
