X3T9.2/87-136









To:       John Lohmeyer
          Chairman, X3T9.2

From:     R. Snively

Date:     August 13, 1987

Subject:  Study of IPI - SCSI queueing functions

D.  Allen  and  I  have studied and discussed the  IPI  and  SCSI 
implementations of queueing.  We have agreed that, with one small 
change,  all the queueing functions of IPI can be performed using 
the  SCSI definitions.   The SCSI queueing definition must change 
the  management of consecutive Head of Queue tagged  commands  to 
LIFO.


All  other differences are minor.   Such differences include  the 
mechanism  for invoking queueing functions and the granularity of 
control of the ordering function.

Sincerely,




Robert N. Snively