RE>Comments on SCAM

jmcgrath at jmcgrath at
Tue May 3 15:48:01 PDT 1994

        Reply to:   RE>Comments on SCAM
I had only one disagrement with Jeff, outlined below:

4)   Should the soft ID be saved to the saved ID to become the current ID
following the a subsequent reset condition or power-on condition?

Larry - The answer seems to be no - the soft ID is never remembered by a
device following a reset condition or a power-on condition.

jpm - I agree

Jeff E. - I disagree.  We need a "warm boot" capability.  The trouble is
that we never agreed to solve this problem -- and I think it's important
that we solve it.  For example, if power has not been removed from the bus
(ie from the level 1 host and peripherals), then an ordinary "reset" that is
not followed up with a SCAM isolation sequence (by the host) should leave
all devices IDs as they were.  This would be a "warm boot"  However, if
the host starts the SCAM sequence, this would be a "cold boot".
This does not seem like a hard thing to do.  Comments?

jpm - the problem is that we are in the process of shipping SCAM devices
implemented as in the specification - we forget the ID on reset, and revert
to the default ID.  Changing that right now is impossible for us.  I suggest
any change be considered a SCAM level 3 action item (what, you thought
things would end at level 2?).  Specifically as part of the next question 
a mode page for SCSI ID.  Note that this still means the host adaptor people 
to work with what is currently documented (i.e. no soft ID) - but as I said,
I think that ship has sailed.

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