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AlphaServer DS15 and Ultrium Tape Drive

Frequent Advisor

AlphaServer DS15 and Ultrium Tape Drive

I am trying to create the following system, but having some difficulties.

AlphaServer DS15
Connected to BA356
Inside the BA356 is a DS-BA35X-FB (dual port, single ended UltraSCSI personality module for BA356(split bus mode))
From the BA356, I have connected a HP Ultrim Tape Drive.

However, when I get my system to a >>> prompt, and issue a SHOW DEV, I only see my 2 internal drives (DKA0, DKA100), and two drives on the BA356 (DKB0, DKB100). I only have 2 drives in the cabinet, so I expect to see that. However, I do not see a MK device anywheres. All my connections are secure. I am assuming there is a jumper setting, or quite possibly a terminator maybe in play. My tape unit is set for SCSI ID 5. Any thoughts or suggestions would be greatly appriciated. Thank you.
Honored Contributor

Re: AlphaServer DS15 and Ultrium Tape Drive

Looks like confusion over BA356 split-bus wiring.

Have a read of the split-bus stuff here:


With the BA356, you have to pull the disk drives to check the box configuration, and the split-bus setting.

If you're on a split-bus box as you've indicated, then you're running, well split SCSI buses. Which means two separate buses in the box. And which means the tap you're connected to is the "other" bus, not the far end of the "same" bus.

(Yep, everybody does the forehead slap when they first run into a split-bus box. soto voce: Been there.)

To switch from split-bus to not-split or to add or remove termination, you have to pull the fans off the back of the BA356.

ps: Tape drives are not permitted on shared buses; on multi-host SCSI buses.

pps: Also check the information for the particular Ultrium drive involved here.