home
***
CD-ROM
|
disk
|
FTP
|
other
***
search
/
InfoMagic Standards 1994 January
/
InfoMagic Standards - January 1994.iso
/
iso
/
9660
/
rockrdge
/
rrg.09
/
susp.nr
< prev
next >
Wrap
Text File
|
1992-08-19
|
3KB
|
93 lines
.bp
.sp
.H 1 "SYSTEM USE SHARING PROTOCOL"
.sp
The System Use Sharing Protocol divides any System Use Area into a
number of variable length fields called System Use Fields.
There may be zero or more System Use Fields in each System Use Area.
Each System Use Field is identified by a System Use Field Signature
Word (described below).
.sp
More than one System Use Field with the same signature word is allowed,
unless otherwise specified in the definition of a specific System Use
Field.
If allowed, the significance of the order, if any, of the recording of
multiple System Use Fields with the same signature word shall be specified
in the definition of the particular System Use Field involved.
In all other situations, the order in which the System Use Fields
appear is not significant.
.sp
Unless otherwise specified in the definition of a specific
System Use Field, each System Use Field recorded in the System
Use Area of the last extent of a multi-extent file shall apply
to all extents of the file and shall override any System Use
Field with the same signature recorded for any other extent of
the file.
Thus, unless an alternate mechanism is provided in
the definition of a specific System Use Field, failure to record
a valid instance of the System Use Field for the final extent of
a multi-extent file shall be treated the same as if this field
had not been recorded for any extent of the file.
.sp
With the exception of the "SP" field, which is recorded as
specified in section 5.3, the first System Use Field
recorded in a System Use Area of any Directory Record shall begin
in byte LEN_SKP+1 of the System Use Area (see section 5.3 [5]).
The first System Use Field recorded in any Continuation
of a System Use Area shall begin in the first byte of the
Continuation.
If more than one System Use Field is to be
recorded in the same System Use Area or Continuation, they shall
be recorded contiguously.
.sp
If the remaining allocated space following the last recorded System
Use Field in a System Use Area is less than four bytes long, it
cannot be a System Use Field and shall be ignored.
Otherwise the use of the System Use Sharing Protocol should be terminated
by the "ST" field or filled with the "PD" field, which are described in
Chapter 5.
.sp
.H 2 "System Use Field Format"
.sp
The System Use Field format is as follows:
.sp
.VL 10 5
.LI "[1]"
"BP 1 to BP 2 - Signature Word" shall specify an identification of a System
Use Field.
This field shall contain two bytes.
Each byte is recorded according to the ISO 9660:1988 Format Section 7.1.1.
.LI "[2]"
"BP 3 - Length (LEN_SUF)" shall specify as an 8-bit number the
length in bytes of the System Use Field, including the
Signature Word, Length, Version and System Use content.
This field shall be recorded according to the ISO 9660
Format section 7.1.1.
.LI "[3]"
"BP 4 - System Use Field Version" shall specify as an 8-bit
number an identification of the version of the System Use
Field.
This field shall be recorded according to ISO 9660
Format section 7.1.1.
.bp
.LI "[4]"
"BP 5 to LEN_SUF - Data" shall contain the content of
the System Use Field.
The format of this field depends on
the Signature Word and Version of the System Use Field.
The Data field is optional.
.LE
.sp
.sp
.TB "System Use Field Description - Version 1"
.TS
center,box;
c | c | c | c | c.
SIG1 SIG2 LENGTH VERSION DATA
(BP1) (BP2) (BP3) (BP4) (BP5 to LEN_SUF)
.TE
.sp
.sp