Comments on Draft 14776-381 (SCSI OMC)

Hayden Smith hsmith at
Thu Jan 21 09:49:51 PST 1999

* From the T10 Reflector (t10 at, posted by:
* Hayden Smith <hsmith at>

Subject: Comments on the Committee Draft 14776-381 -Small Computer
System Interface -Part 381: Optical Memory Card Device Commands (SCSI
OMC). 99-107R0 on T10 site.

I have a number of comments I would like to share about the OMC command
set defined in the above document.  Some of my comments are correcting
spelling and grammer,  in other places I have re-written paragraphs.  I
welcome any comments.

I do not think the first two paragraphs of the Introduction (page iv)
are appropriate for the introduction of a new class of SCSI device.
There is an opportunity here to give more information about the device
and the properties of the media.

Remove the first two paragraphs, replace with,

This SCSI-3 Optical Memory Card (OMC) command set specifies the commands
for a device that declares itself as an optical memory card device in
the device type field of the INQUIRY command.  The OMC command set is
specified independently of any service delivery subsystem, an underlying
command-response protocol is assumed.

The optical memory card is a Write Once media, a written area cannot be
overwritten.  Information stored on an optical memory card is

The FORMAT UNIT command is not defined for optical memory card devices.
The media is manufactured with preformatted information.  The
specification for the pre-formatted area is defined in ISO 11694, part

Data written to the optical memory card cannot be updated.  Therefore
the update commands are not defined for optical memory card devices.

Introduction, paragraph 3, sentence 2.
Remove this sentence. (This information is now contained in point 1

Clause 2, sentence 2. 
Replace "was" with "were".

Clause 2, sentence 4.
Replace "Member" with "Members".

Clause 3.1.6
Replace "have" with "has".

Clause 3.1.11
Replace "... distinguishes kind ..." with "... distinguishes the kind

Clause 3.1.12
Replace "... that are not ..." with "... that is not ...".

Clause 4.1.  
Add the following paragraph before the first paragraph.
"An OMC device is a device the returns Fh in the PERIFERAL DEVICE TYPE
field of the INQUIRY command response data."

Clause 4.1. paragraph 1, sentence 2.
Replace "In several respect, ..." with "In several respects, ...".

Clause 4.1. paragraph 2, sentence 1.
Replace "The sector ..." with "A sector ...".

Clause 4.2, paragraph 1, sentence 2.
Remove last five words "for optical memory card devices."

Clause 4.2, paragraph 2, sentence 1.
Replace "... both address types, address types ...",
with "... both address types, the address type ...".
Replace "... by setting an address type (AT) bit of optical memory ...
with "... by setting the address type (AT) bit of the optical memory ...

Table 2.
In the note at the bottom of the table remove the "e.g.". 
Replace the ", or" with "and".

Clause 4.3, sentence 1.
Remove the word "a".

Clause 4.3, point 1.
Replace "a medium in ..." with "medium in ...".

Clause 4.6, paragraph 3, sentence 2.
Replace "At least the data read...".,
with "The data read...".

Clause 4.6, paragraph 4.
Replace "... first non-blank encountered.",
with "... first non-blank block encountered."

Clause 5.1, paragraph 1, sentence 1.
Replace "... regarding the capacity of the logical unit."
with "... regarding the capacity of the media in the logical unit."

Clause 5.1, paragraph 5, sentence 1.
Replace "... one, All ..." with "... one, all ...".

Clause 5.1, paragraph 5, sentence 2.
Replace "If not the..." with "If not, the ...".

Clause 5.1
Insert the following paragraph after paragraph 5.
"If the OMC device does not contain media then it shall return a CHECK
CONDITION status, the sense key shall be set to NOT READY and the
additional sense code set to MEDIUM NOT PRESENT."

Clause 6.3, paragraph 3.
Remove and replace with, 
"The mode parameter sent by the MODE SELECT command shall be valid until
either a UNIT ATTENTION condition is generated by a RESET condition
occuring, or the mode parameter is changed."

Clause 6.3, paragraph 9, sentence 2.
Replace "... with block zero and be contiguous..."
with "...with block zero and is contiguous..."

Clause 6.3, paragraph 9, sentence 4.
Remove and replace sentence with,
"Each partition is specified by a type of sector (defined as a density
code, see Table11) and a number of logical blocks."

Clause 6.3, paragraph 9, sentence 6.
Remove and replace sentence with,
"This means the user is responsible for managing partition definitions."

Clause 6.3, paragraph 10, sentence 1.
Remove and replace with,
"Definition of partitions by the MODE SELECT command are valid
regardless of a card being present in the logical unit."

Clause 6.3, paragraph 10, sentence 3 and 4.
Remove and replace with,
"When a user defines multiple partitions on a card the partitions must
be set up without blank spaces.  The partition numbers shall be assigned
sequentially by the logical unit starting with partition zero."

Clause 6.3, paragraph 10, sentence 5.
Replace "The partition zero..."
with " Partition zero...".

Clause 6.3, paragraph 13, sentence 1.
Replace "... bit of zero advises the target to disable the blank
with "... bit of zero disables the blank checking...".

Clause 6.3, paragraph 13, sentence 3.
Replace "operations" with "operation".

Table 11, NOTES.
Replace "Reference International Standard."
with "International Standard 11694-4."

Clause 6.3, paragraph 18, sentence 2.
Replace "respond" with "response".

Clause 6.3, paragraph 18, point b.
Remove and replace with, "When a logical unit comes to the ready state
after medium loading, the default value described in item a) shall be
reported.  The number of blocks field shall be set to the maximum
logical block number (track number) of the loaded medium.  If a logical
unit does not come to the ready state after the medium is loaded, the
most recent mode parameter block descriptor (initial default value
described in item a), when the card was first loaded) shall be reported.

Hayden Smith.	email: hsmith at
LaserCard Systems Corporation.
Tel: 650 969 4428.

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