all the twists of the edit of a mode page?

Mon Sep 16 12:06:15 PDT 1996

* From the SCSI Reflector (scsi at, posted by:
Hasn't someone somewhere out on the Web
already put together a technical note
explaining how to edit a SCSI-2 mode page?

People perenially forget one of the N steps
that I read as required by one of the N
(extraordinarily discontiguous yet relevant)
pages of the standard.

In short I would say ...

() Try x1A mode sense with the [x01].x08 DBD
bit set, else resort to x1A mode sense with
that bit clear.

() Extract the additional length and cook as
usual to find how much data the target can

() Get all the data possible.

() Strip off the header, and block
descriptors if need be.

() Insert an all zero, four byte header,
presuming the [x01] media type was zero -
else I don't quite remember what to do.

() Copy only the six [x00].x3F bits of the
page code - in particular NOT the [x00].x08
PS parameters-saveable bit.

() Send the data back via x15 mode select,
with the length adjusted if need be to
reflect a change in header length.

() Send another x1A mode sense to see how
the drive cooked your data.

() Overall, retry from the top to get past
SK = x6 unit attentions, if need be. 
Whenever you tire of retrying, bail.

Of course I'd rather steal a complete note
targetted at the novice audience than write
one.  Particularly if I've forgotten some
crucial step myself in the above summary.

Perhaps such a thing does exist?

Thanks in advance.   Pat LaVarre

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