SCSI cable question

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Dr. Webster's picture
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I just got a 2-bay external SCSI drive case, and am planning on installing two Ultra SCSI drives in there. I'd like to put both drives on the same bus so I can have OS X drop them into a RAID array. Problem is, the case has two separate internal SCSI ribbon cables -- one for each drive. Each internal ribbon has a single 68-pin connector for the drive, and two external 68-pin connectors (so there's a total of 4 connectors on the back of the case). What I'd like to know is if I can simply add another internal 68-pin connector to one of the ribbons. If I can, are there any specific guidelines I need to follow, e.g. there must be a specific distance between the connections?

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dankephoto's picture
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re: add another internal 68-pin connector

Yes you can add a second connector internally and there's no minimum distance requirements except what you need to mechanically connect what you've got in there.

Alternatively, you could just jumper the external connectors with a short 68M-68M ribbon. I regularly use internal ribbon cable and connectors for this sort of thing, it's the same connector as the externals. The nice thing about this second approach is that you can still put the two drives on separate buses if you need to without having to futz with reconfiguring the boxes innerds.

Keep in mind any existing drives in such a box are probably already separately internally terminated, so if you run them onto a single bus you'll need to reconfigure the termination (and IDs too, probably.)

dan k

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catmistake's picture
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easier solution

It'd be easier (though more expensive) for you to get another short external scsi patch cable, and connect one connector to the other... that would also get them on the same bus. At least you wouldn't risk messing up the box for good.

Dr. Webster's picture
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Re: easier solution

catmistake wrote:

It'd be easier (though more expensive) for you to get another short external scsi patch cable, and connect one connector to the other... that would also get them on the same bus. At least you wouldn't risk messing up the box for good.

I'm not worried about messing up the box. I don't want to use an external cable because my network closet is a rat's nest of cables as it is. I found a local shop that carries 3-device 68-pin cables, so I'll probably just pick one of those up and hack it to an external connector.

In a side question, does anyone have a PCI Ultra SCSI card that will work in a B&W G3 that they'd like to get rid of/donate? I could use a 68-pin external SCSI cable too...

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dankephoto's picture
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re: does anyone have a PCI Ultra SCSI card?

Will you be running X or classic? If classic, I have an FWB card that'd work dandy, it doesn't appear to work under X though. Cables internal and external too . . . see my sig for email addy.

dan k

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Dr. Webster's picture
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Needs to work under Tiger Ser

Needs to work under Tiger Server. Doesn't have to have RAID capability.

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catmistake's picture
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Re: Re: easier solution

Quote:

I'm not worried about messing up the box.

oops... didn't even look to see who I was responding to... my bad