Very old SMC typo - Suggested Fix

Terry Spear terrys at
Fri Jun 21 10:20:54 PDT 1996

* From the SCSI Reflector, posted by:
* Terry Spear <terrys at>
>The diagram illustrating the Media Changer Mode Select Device Capabilities
Page has an inconsistency in it that dates back to the SCSI-2 standard.
>Reference p60 of SMC rev 05.
>The Page Length field value is 12H.
>The page length shown in the diagram is 0EH.
>A brief survey of implementations show that that many assume the page
length value of 12H is correct and add 4 reserved bytes to the end of the
data structure: Exabyte, Breece Hill, MountainGate. Some chose to interpret
this inconsistency by changing the page length value to 0EH: DEC->Quantum.
>Please lets remove this inconsistency if possible before going to print
with SCSI-3.

I suggested the following change to prevent creating non-conformance with
existing devices: Change Table 27 by adding an optional 4 byte vendor
specified field after byte 15 and redefine the page length value as 0EH if
the optional field is present, 12H otherwise.

Terry L. Spear				MountainGate, Inc.
terrys at	Lockheed Martin
303-413-8544				6287 Arapahoe Road
303-413-8593(fax)			Boulder, CO 80303

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