ZIP drive on SCSI segment w/ other devices -- problem or not?

[Brian Ristuccia]

On Tue, Dec 01, 1998 at 05:04:02PM -0500, James W. Durkin wrote:
> I've been warned off of placing a SCSI Insider ZIP drive on the same
> segment (the 50-pin narrow connector of an Adaptec 2940U2W PCI card) as
> other devices such as CD-ROMs.  The expected problems have been variously
> described as "will damage the other devices on the segment", or "will
> cause the controller to reset indefinitely".  Nothing particularly
> specific, and nothing I've been able to confirm from looking through the
> various unofficial Iomega sites on the web.

Sounds typical of the crappy Iomega zip products. My parallel port zip drive
crapped out after only a year and was ass-slow. My SCSI zip drive refuses to
play nice with ultra devices on the chain and just recently started making
an obnoxious clicking noise. 

> 
> Instead, it's been suggested, that it should be driven from the supplied
> (Adaptec sourced, I guess) controller.  Seems a waste of an ISA slot, plus
> cabling hassles, etc.  But if there is a legit reason for it, I guess it's
> tolerable.
> 
> So, truth or fiction here?
> 

The external SCSI zip drive uses absolute crap for connectors and cabling.
The 25 pin connectors are not standard and will cause all kinds of hassles
if you're trying to run ultra speed over that bus or chain other devices off
the back of the zip drive. If you're going to use one of these, I suggest
putting it at the end of the chain, and disabling ultra speeds on that bus.

I have a 2940AU for my slower SCSI devices, many of which are notorious
offenders on the SCSI bus. I have an Archive DAT changer, a HP Surestore
6020 cdwriter, a HP Scanjet IIc, and the zip drive on this bus. None of the
devices run at ultra speeds, and it seems to be OK. The zip drive is at the
end using its internal termination. I put my good devices on a 7880 and run
them ultra-wide. 

If the insider zip drive is anywhere near the low quality I've experienced
with other Iomega zip drive products, you may get stuck putting it on its
own controller. As for the damage issue, it sounds unlikely, but perhaps
these statements have been made to keep Iomega from having to support
complicated configurations. My HP6020 came with a similar warning, and it's
been connected and in use for months without any trouble. 

-- 
Brian Ristuccia
brianr at osiris.ml.org
bristucc at baynetworks.com
bristucc at cs.uml.edu

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