Each WORM cartridge also has a 12-byte, unique, worldwide cartridge identifier (WWCID). This WWCID is
made up of 4 bytes of the unique CM chip serial number and 8 bytes of the unique tape media serial
number.
When the drive senses that a cartridge is a WORM cartridge, the microcode prohibits the changing or
altering of user data that is already written on the tape. The microcode tracks the last appendable point
on the tape by using an overwrite-protection pointer that is stored in the cartridge memory (CM).
SARS data can be written and updated on WORM tapes because the SARS data is not in the user area of
the tape.
Tape drive
The 3592 tape drive is housed in a canister. The two components are assembled into a single FRU called a
drive canister. The drive canister is installed in a rack enclosure that can house two canisters. The
enclosure includes redundant DC power supplies and appropriate cables and cards that provide power
and signals to the drives.
No power ON/OFF switches are on the 3592 tape drive canister. Because the drive canister and the power
supplies are single FRUs and are hot-pluggable, they do not require power ON/OFF switches to allow the
customer engineer to complete service activities.
The tape drive has an operator display with an eight character display at the front bezel of each drive. The
operator uses this panel when in Operator Mode. VOLSER, status, and error messages display here as
they occur.
Drive layout
The operator bezel (used by the operator) and the service panel (not available to the operator) provide
menu-driven displays. The operator and the service representative use these controls to display
information, set different options, and complete tasks such as -
• Device status
• Error conditions (FID)
• Drive set up
• Mount activities
Operator bezel
Each 3592 drive has a faceplate or bezel (called ‘drive front panel' in customer documentation) installed
on the front, and contains these controls, indicators, and functional areas.
• An 8-character display
• Unload button
• Reset button
• Power-on LED
• Fiducial
The bezel contains white-colored areas that are called fiducials. A fiducial is used by the library device to
help “teach” the library the position of the drive, that is, where the drive is located. Figure 2 on page 29
shows the operator bezel, and Table 14 on page 29 lists the corresponding active (or functional) areas of
the operator bezel.
28 IBM 3592 TS1140, TS1150, TS1155, and TS1160 Tape Drives: Maintenance Information