Technical information
SEGA Confidential
SATURN Virtual CD System User's Manual
27
Volume Definition
The lead-in and 2-second gap are followed immediately by the system area and the
volume descriptor set portion. See the DISC Format Standard Specifications (ST-040-
R4-051795).
<SystemArea line> defines the system area. The content of the file specified as the
parameter of this line is copied to the system area. When the file length is less than
16 sectors, the remainder is filled in with
0x00. When the file is too long to fit, an
error results.
The volume descriptor set includes the following types of volume descriptors. See
page 15 of the DISC Format Standard Specifications (ST-040-R4-051795).
• Primary Volume Descriptor (PVD)
• Supplementary Volume Descriptor (SVD)
• Boot Record (BTR)
• Volume Partition Descriptor (VPD)
• Volume Descriptor Terminator (VDT)
There must be at least one PVD, which is always defined. The other volume descrip-
tors are defined as necessary. There may be multiple primary volume descriptors.
However, when several PVDs are present, the latter PVD becomes valid.
A line is provided for defining each of the volume descriptors except the last (VDT),
which is generated even when it is not specified. Therefore, there is no line that
defines this volume descriptor. The end of the volume descriptor set definition is
denoted by
<EndVolume line>.
• Line for defining PVD
The PVD is defined in the section between <PrimaryVolume line> and
<EndPrimaryVolume line>.
• Line for defining SVD
The SVD is defined in the section between <SupplementaryVolume line> and
<EndSupplementaryVolume line>.
• Line for defining BTR
The BTR is defined in the section between <BootRecord line> and
<EndBootRecord line>.
• VPD is not used with the Saturn game disc.
The parameters PrimaryVolume, SupplementaryVolume, and BootRecord are specified
by their relative positions within the sessions on the disk. There are lines corre-
sponding to each of the volume descriptor fields. The keywords of the lines indicate
fields, and the parameters indicate their values.
• SystemIdentifier (PVD, SVD), BootSystemIdentifier (BRT)
Specifies the system identifier names of the volume descriptor via parameters.
• VolumeIdentifier (PVD, SVD)
Specifies the volume identifier names via parameters.
• LogicalBlockSize (PVD, SVD)
Specifies the logical block size of the volume as a parameter. The logical block sizes permitted are
512, 1024, and 2048.