difference in the position of the BOT (beginning of tape) hole (see
Figure 7-4). The BOT hole is a small hole in the tape that tells the drive
that the leader has passed the read/write heads and it’s now safe to start
recording. The distance from the beginning of the leader to the BOT
hole tells the tape drive what type of cartridge is loaded, the maximum
native capacity, and the length of the tape in feet.
Another small difference is that DLTtape cartridges come in four
different colors. The casing for DLTtape III cartridges is dark gray,
DLTtape IIIXT cartridges are white, DLTtape IV cartridges are black,
and the CleaningTape III cartridge is cream colored. Super DLTtape I
cartridges are black, and have a distinctive textured finish, (See Figure
7-5.) These differences make it easy for users to differentiate between
tapes, especially in a situation where there are several different mod-
els of DLTtape drives working.
A major difference among the types of DLTtape media is capacity.
The DLTtape III cartridge has a native capacity of 10GB, the
QUANTUM DLTtape HANDBOOK
7.5
Leader Splice
Scratch
Area
Calibration
Area
Directory
Area
DATA
SCRATCH AREA
■
Set Write Currents
■
Determine optimal tape
Tension
■
Individually adjust Write
Current for each write gap
CALIBRATION AREA
■
Position head in vertical
■
Determine optimal azimuth
position (DLT 7000)
■
Line up data tracks with cal
tracks for Interchange
■
Density Detection
DIRECTORY AREA
■
Used for Fast Search
BOT HOLE
■
Physical Beginning of Tape
EOT HOLE
■
Physical End of Tape
Figure 7-4 DLTtape Media Format
features areas for calibration,
directory, and holes to indicated beginning and end of tape. Position of
BOT hole helps drive identify cartridge type.