[comp.periphs.scsi] the START UNIT command

det@hawkmoon.MN.ORG (Derek E. Terveer) (12/07/90)

I am trying to implement power sequencing of drives in a scsi (st01) disk
driver and have run into a few problems.  At first, I couldn't get the drives
to respond to my command -- all they did was sit there flickering their front
panel LEDs after the command was sent and the drive was pretty much unusable.

So, eventually, i tried putting in a delay after the command was sent and that
seemed to work on one drive (wren iv) but the other drive (wren iii) seems to
not want to respond.  I *was* able, at one time, to get the wren iii to start
but i can't get it to do it any more.  Sigh.  Neither drive will allow me to
stop the spindle.  Are there any tricks to this?  A certain amount of delay?
Always look for a disconnect, etc????

derek

Please send replies via email to:	det@hawkmoon.mn.org
-- 
Derek Terveer						det@hawkmoon.MN.ORG
Minnesota Field Hockey Association,  North Central Section
University of Minnesota Women's Lacrosse,  Midwest District

det@hawkmoon.MN.ORG (Derek E. Terveer) (12/07/90)

In article <1990Dec7.070847.1699@hawkmoon.MN.ORG>, det@hawkmoon.MN.ORG (Derek E. Terveer) writes:
> I am trying to implement power sequencing of drives in a scsi (st01) disk

In order to fend off a flury of suggestions along the lines of "Make sure that
the motor start option is enabled," I *did* enable the motor start option on
both drives...

derek
-- 
Derek Terveer						det@hawkmoon.MN.ORG
Minnesota Field Hockey Association,  North Central Section
University of Minnesota Women's Lacrosse,  Midwest District

gibson@b11.ingr.com (Stan Gibson) (12/11/90)

In article <1990Dec7.070847.1699@hawkmoon.MN.ORG> det@hawkmoon.MN.ORG (Derek E. Terveer) writes:



>but i can't get it to do it any more.  Sigh.  Neither drive will allow me to
>stop the spindle.  Are there any tricks to this?  A certain amount of delay?

Most Wren products will not allow you to spin them down via software
command. When I asked them about this they claimed they preferred you
let the drive spin down on power down so they could use the "back emf"
generated by the motor. Try using another vendors drive.