I've copied two messages that went back and forth between Danny Mitchell and
me. I thought they might be of general interest to the groups.
Regards,
Peter Johansson
Congruent Software, Inc.
3998 Whittle Avenue
Oakland, CA 94602
(510) 531-5472
(510) 531-2942 FAX
pjohansson@aol.com
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In a message dated 97-06-19 00:17:33 EDT, DMitchell@ti.com (Danny Mitchell)
writes:
<<Some of the discussions here indicate that a printer might need to be both
initiator and target?? The discussion is along the line of compatability
with the 1284 protocols that have been developed for printers. I am still
investigating that, I do not really see the need for this type of complexity
for sending status data.>>
I haven't been part of the discussions about the necessity for a printer to
be a "targiator" and fulfill both roles, so perhaps I am missing something
when I say I do ot see the need for that sort of complexity, either.
Is the printer you contemplate FUNDAMENTALLY different from the model
implemented by parallel SCSI printers today? If it's much the same, there is
no need for the printer to be anything other than a target. The SBP-2 status
mechanisms, both that associated with a particular ORB and unsolicited
status, should be adequate.
Regards,
Peter Johansson
Congruent Software, Inc.
3998 Whittle Avenue
Oakland, CA 94602
(510) 531-5472
(510) 531-2942 FAX
pjohansson@aol.com
************************************************************
In a message dated 97-06-22 01:27:36 EDT, DMitchell@ti.com (Danny Mitchell)
writes:
<<What about the case where the printer would want to send data back to the
host for status reporting ( paper out, status of job, etc. ) and other
things that the printer group has defined using the 1284 specification ( I
believe it defines bi-directional communication channels ).>>
This sounds like unsolicited status to me; covered by SBP-2.
<<Can I assume that a printer could provide "read" functions like a HDD
would?>>
You can provide any commands you want; for any one command the data can
either move from the initiator (e.g., PRINT) or to the initiator (e.g.,
REQUEST SENSE).
What are the addresses of the various PWG reflector(s)? I should be answering
these questions for the whole group.
Regards,
Peter
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