Quadra 700 HDD jumper weirdness

[John8520]

So I have a quadra 700, and I have a series of seagate SCSI drives I can put in it. This week's drive is a Seagate Medalist ST39140N, 9.1GB, 7200rpm, very nice. It has the standard two jumper blocks that just about all STxxxxxNs have; one on the front for the SCSI ID and remote LED, and one on the bottom for termination, parity, write protect, etc. It's ID is always 0.

90% of the time I have only one other SCSI device attached, a very nice caddy load CD-ROM that has auto termination, set on SCSI ID3. Now, I know this setup works. Just 5 minutes ago I booted off a 7.6.1 CD and installed 7.6.1 on the 9.1GB HDD with no problems whatsoever.

Until I removed the CD drive, that is. With that off the machine just boots to the blinking "?" we all know and love. First idea is that it's just SCSI termination, so I sourced some unbelievably tiny jumpers and set the first two that came to mind, term enable and term power from drive. This time when it boots, it displays the little box giving some information on the silverlining driver, and that it's set to ID0, but it still sits at the blinking "?"

What the heck is going on? Are there other SCSI term jumpers I need to set?

 

[Aoresteen]

Sound like you need to terminate the hard drive. It appears that the CR ROM was terminating the SCSI chain.

With external devices I NEVER use on-device termination. I always use an external terminator. That way I know all devices are free from termination and I don't have to crack a case open to extend the chain.

 

[Franklinstein]

Maybe try setting the "term power to SCSI bus" jumper. I know I have lots of Seagate drives, and that's usually an option that I choose.

I'm pretty sure that you can still get the manuals from Seagate - they're the only other hard drive company that still keeps stuff for virtually every hard drive they've ever made. Maybe they don't keep docs for 14" or even 8" drives, but I know first hand that they've got specs for 5.25" and 3.5" drives from at least 1988.

 

[equill]

TE and TP (termination power from drive, second-last of the two TP pairs) are the commonest default settings for narrow (STxxxxxN) Seagate drives, and often for STxxxxxW also, unless the options are not present.

That you get the Silverlining splash screen during startup indicates that the Silverlining drivers are installed on the HDDs. Is the Silverlining CP also in the Control Panels folder of your drive(s)? Have you configured the SCSI bus, drive and volumes (if the drive is data-partitioned) in the Silverlining CP? Come to think of it, are you using Silverlining 6.x, with an excellent, informative and intuitive GUI, or 5.x, with a skeletal and rather arcane almost-GUI?

At the very least, it may pay you to ensure that your startup volume is so designated in Silverlining. You should also take note of Aoresteen's diagnosis. Temporary relief may be available by selecting the HDD as startup volume in the Startup Disk control panel before you shut down and disconnect the external CD-ROM. The effectiveness of this, however, depends on the presence of a functional PRAM battery in the Mac.

de

 

[trag]

This is probably not the problem in your case, but it could be.

Set termination on. Set Termination Power off. There are three or four options for Term Power on the Seagate drives. Set it to Term PWR from SCSI bus.

The host computer should supply termination power. If you have more than one device supplying termination power, you sometimes end up with voltage level contention between the voltage regulators involved (which are set at slightly different levels) and then all kinds of wackiness and over-current drawing stuff happens.

Or so sayeth the Seagate Tech Support Guru I spoke to back in 1995 about my array of ST32550W drives.

Now, in most cases the settings for Term Power on the drive don't matter, because the host computer is supplying it, and a little extra doesn't always cause interference. But with my bunch of Seagate drives, it would not work properly until I stopped sending term. Power to the bus from the Seagate drives.

So, maybe you'll get lucky and this will be your experience too. It would be a simple fix.

 

[John8520]

That sounds very possible... When I get home I'll try it out and see what I can do.