<<< SSAG::DISK$ARCH2:[NOTES$LIBRARY.SSAG]ASK_SSAG.NOTE;32767 >>> -< Ask the Storage Architecture Group >- ================================================================================ Note 429.24 SCSI Reselection phase and RZ23 24 of 32 JACOB::HOUSE "Kenny - MLO5-2/B6 - DTN 223-6720" 39 lines 21-MAR-1990 05:45 -< PVAX ROMs know about spinning up drives (or not) >- -------------------------------------------------------------------------------- RE: setting and clearing the RZ22/23 DSP (disable spinup at power-on) bit... If you've got a PVAX with the SCSI-SCSI storage option, there's a sneaky trick in the ROMs that'll let you change the DSP (disable spinup at power-on) bit. You need one of those MMJ loopback connectors that look like a red spoon; that gets you into "field service" mode where you get to do dangerous things. Put the spoon in, and power on the unit. At the console prompt, type "T 73" to start the Tape Key Utility. Don't worry about the name, 'cause it's only the magic inside this code we want to get. Answer the questions about which port and which ID the drive is set for. I can't remember whether the code allows you to specify a LUN (logical unit), but if the question comes up, answer that one too. When the "RUsure" question comes up, answer "41000001" -- this is part of the strong magic I alluded to before. The code will do a MODE SENSE, then turn around and issue a MODE SELECT with the DSP bit clear. Ultimately, the code will report an error, but don't worry: it's complaining that the device isn't a tape (remember this used to be a tape key utility?). Take out the spoon and cycle power again to get out of field service mode. No sense aggravating the gods by leaving too many privileges on. That should do it. The drive should spin up at power on now. If you want to get things back the way they were, perform all the above steps but answer "42000001" to "RUsure." That'll set the DSP bit. Having said all that... The reason we didn't want the RZs spinning up at power-on was that the current surge of three drives spinning up simultaneously was too much for the PVAX power supply. Software took it upon itself to bring these drives up one-at-a-time. Hope this helps, -- Kenny House