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Powerbook 165 with two external SCSI zip disks

D

Den2016

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Joined
Aug 18, 2016
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44
Location
Toronto, Canada
I picked up a SCSI Zip 100 Plus recently and along with my SCSI Zip I thought I would be able to setup a SCSI daisy chain with the two devices.
I'm encountering System bus errors when trying to connect the two to my Powerbook 165.

So maybe someone can help me?

IMG_2040.jpg

I've included a picture of the two devices together. Notice that the Zip Plus device offers a SCSI ID switch however it also provides an Auto-detect
DB25M interface. Given that it also doesn't provide a termination switch, I'm assuming it also auto-terminates.

So there are two ways to set it up. One is where the Zip Plus is at the end of the chain. This was my first attempt and it's where I'm experiencing
a bus error. The alternative method is have the other SCSI Zip at the end of the chain. The Powerbook doesn't recognize a boot device in this case.

So when I hook up the PB direct to either drives (individually) they work successfully. That is, PB <-- --> SCSI Zip (term on, scsi id = 5) Ok
PB <-- --> SCSI Zip Plus (auto-detect) Ok

So a few questions.

If I purchased the SCSI Zip today brand new, what SCSI cable would be provided in the box?
If I had 2x SCSI Zip drives I would need a DB25M to DB25M cable to connect the two drives correct?
Then why would an auto-detect (on the zip plus) be a DB25M when the SCSI zip has two DB25F connectors?

My guess is that the two cable I have (they are both branded iomega on one end and zip on the other end, i.e. DB25F to DB25M) *may* be the wrong
cable? I.e. they could be cables for the parallel port version zip as opposed to the SCSI zip?

Thanks
 
The ZIP Plus drive used a special cable because of the dubious "AutoDetect" feature, so you're kind of screwed. I don't remember the details but a straight-thru DB25M-M won't work. I suspect once you get this cable it will "just work" as long as the ZIP Plus is in first position.
 
Ok, that's kinda weird. It works when the zip plus is connected directly to the computer (with a DB25M-M straight-thru and a HD30M-DB25F dongle), but it won't allow me to daisy chain?
Yet, it *should* work with the auto-detect cable? That's irritating.

But ... there is a Zip plus for sale like an hour away and it's not expensive. I can go get it and give it a try.
 
When I had the Zip plus (at the end of the chain) as SCSI ID=5 and the standard SCSI Zip as SCSI ID=6,
the Mac at first only detected the Zip plus!? Only after a rescan did it see both drives.
But it wouldn't read from the standard SCSI drive (intermediate drive) ?!

So this is just wild ass guessing, but it seems there is a physical passthrough (i.e. being middle of the chain)
and a logical passthrough (having a lower SCSI ID has higher priority).

So yeah, I'm glad it worked. :)
 
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