User's Manual

AMERICAN NATIONAL STANDARDS INSTITUTE (ANSI) LABELED TAPES
1-2 XEROX LASER PRINTING SYSTEMS TAPE FORMATS MANUAL
The beginning-of-volume label identifies the volume and its owner
and is often referred to as a volume label. Other labels are called “file
labels” and are either header labels (if they precede the file) or trailer
labels (if they follow the file).
The Xerox/OSS can process four tape configurations:
• Single file, single volume
• Single file, multiple volume
• Multiple file, single volume
• Multiple file, multiple volume.
ANSI labeled tape structures
The locations of the types and classes of labels in these
configurations are shown in figures 1-1, 1-2, and 1-3. Figure 1-1
shows ANSI labeled tape structure when no optional labels are used.
Figure 1-2 shows ANSI labeled tape structures with end-of-file (EOF)
and end-of-volume (EOV) marks coinciding.
• In general, the pattern shown in option 1, figure 1-2, occurs
when the end-of-tape reflective strip is reached while writing the
last block of a file. Usually, the operating system does not yet
know that this is the last block, and the EOV label group is
recorded at this time.
• On the other hand, the pattern shown in option 2, figure 1-2,
occurs when the reflective strip is reached after the EOF label
group has been started.
• The pattern shown in option 3, figure 1-2, permits the initiation
of any file within a file set at the beginning of a volume. When
this configuration is used, the block count (field 12) of the end-
of-volume label is undefined. File sets are not terminated by an
end-of-volume label group.
Table 1-1.ANSI labels
Type Operating system labels User labels
Beginning-of-volume VOL1 (required (Additional VOL labels
prohibited)
UVL1 to UVL9 (optional)
Beginning-of-file HDR1 (required) HDR2 to HDR9
(optional)
UHLa (optional; unlimited number
allowed)
End-of-volume EOV1 (required) EVO2 to EOV9
(optional)
UTLa (optional; unlimited number
allowed)
End-of-file EOF1 (required) EOF2 to EOF9
(optional)
UTLa (optional; unlimited number
allowed)