Minutes of SSC/SMC working group 11/9/95
tedl at smtplink.exabyte.com
tedl at smtplink.exabyte.com
Fri Nov 17 12:28:59 PST 1995
SSC/SMC Working Group Minutes - November 1995 X3T10/95-359r0
To: Membership of X3T10
From: Edward Lappin
tedl at exabyte.com
Date: November 9, 1995
Subject: SSC/SMC Working Group Minutes
1. Opening Remarks
Ted Lappin, the SSC Technical Editor, called the meeting to order at
9:05 a.m., Thursday, November 9, 1995. He thanked Jeff Stai of Western
Digital for arranging and hosting the meeting.
As is customary, the people attending introduced themselves and a copy
of the attendance list was circulated.
The draft agenda was approved.
2. Attendance and Membership
Attendance at working group meetings does not count toward minimum
attendance requirements for X3T10 membership. Working group meetings
are open to any person or organization directly and materially affected
by X3T10's scope of work.
The following people attended the meeting:
Name S Organization Email Address
Mr. Edward Lappin P Exabyte Corp. tedl at exabyte.com
Mr. Bill Dallas A Digital Equipment Corp. dallas at zk3.dec.com
Mr. Pat LaVarre Iomega p.lavarre at ieee.org
Mr. Wesley Hale Unisys Corp. wes.hale at mv.unisys.com
Mr. Ken Hallam P Unisys Corp. ken.hallam at mv.unisys.com
Mr. Ralph Weber A ENDL roweber at acm.org
6 People Present
Status Key: P - Principal
A - Alternate
3. SSC Topics
3.1 Soft Write Protect
Wes talked about why the soft write protect bit is where it is. We
moved it according to Arlan Stone's document last time but there was
activity on the reflector about why it should be moved back. Bill
Dallas asked about whether or not that this bit is savable as a Mode
parameter. Other devices, but not all, could use this bit. In
particular, CD ROM may want to use it.
Arguments for device configuration page:
1. More appropriate for the page. It is a configuration.
2. May not want to save this field. If don't save, should be on
page that is also not saved.
3. Read/write recovery page is only superficially the same for
Arguments for read/write recovery page:
1. More consistent with disk and CD-ROM drives.
1. May be useful to write protect and save for the cartridge.
However, still have to write to it to save the mode parameter.
2. If really want to save parameter on media, should be command
since Mode parameters are not necessarily saved on the drive.
3. Writing to media for a non-write command upsets some users.
This also is a problem with savable Mode parameters.
4. Argument about when UA for mode parameters occurs. Question
about how many UAs are OK. For example, doing both power-on
and media changed, many cheap drivers cannot take multiple
check conditions (they don't check for the reason).
Conclusion is that we cannot guarantee commonality and we should not
worry about it at this time. Therefore, due to better location, we
should have it in the device configuration page (no change). This page
fits the functionality better.
3.2 Clarification on Report Density
Ken wants clarification on defaults. In particular, for the media
default density (not drive default), what will be written if we are
writing. The media bit indicates the capabilities of the drive in
combination with the currently loaded media. The command is for
reporting capabilities, not written data.
Also noted, this may apply to other command sets. However, it is up to
other command sets to adopt this mechanism.
3.3 Write Buffer
Ken does not like the current Write Buffer proposal. Clarity is
required. Ken wants to know why we did Write Buffer mode 7 the way it
is done. Loading may require looking at file (Bill) to make sure file
is already correct.
3.4 Samonize the document
To do this, need to make sure:
1. Data in/out phase converts to "Data-In buffer" or "Data-Out
buffer". This is in section 4.1 (The request -response model)
2. Initiator converts to application client or initiator.
Application client does most of the commands. If initiator and
not the thing sending the command or getting status back, then
it is probably the initiator. If sending or receiving,
probably the application client.
3. Target converts to device server or logical unit or target.
Logical unit is for thing that contains information for the
LUN. The device server is the typical target. For SPC, Mode
pages went to the logical unit or target, depending on the
scope of the data.
I pointed out that the valid bit is not set on a Locate failure. This
is because there is not a residual on a Locate since there is no concept
of residual because blocks are not numbered in a particular way.
3.6 Block numbering
Bill would like to specifically specify that blocks are numbered
sequentially. He needs to bring a proposal to change this aspect of the
model since, while not violated by current drives that we know of, it is
a major change.
4. SMC Topics
There were no SMC topics. The editor of SMC, Erich Oetting, was not
5. Adjourned at 11:00 AM.
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