Tandberg Data
Introduction to the Drive
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2-8
Tandberg SLR Reference Manual
Capstan Motor System
The Capstan Motor System consists of a brushless DC motor controlled by a quartz crystal
controlled servo loop. The speed sensors are Hall elements. Start and stop ramps are fully
controlled by drive firmware to assure optimum ramps and gentle tape handling.
Aside from moving the tape, the capstan motor system is also used to load and eject the
cartridge.
Cartridge Manipulation (CAM) System
The Cartridge Manipulation System uses a dedicated motor (the CAM motor) in addition to
the capstan motor to move the cartridge in and out of the Drive.
See Appendix B
Appendix B describes how to manually eject the cartridge in case of accidental power-down
or other error situations.
Tape Hole Sensor
The optical Tape Hole Sensor system features physically individual systems for the two tape
hole positions (upper and lower) to provide very high system reliability (especially against
tape runout). The sensitivity of the sensors are adjusted to achieve good design margins.
Pulsed light and synchronous detection are used to achieve sensitive systems that are very
tolerant to stray light.
2.5. Interface to Host
The Tandberg SLR7, SLR60, SLR75, SLR100 and SLR140 conform with the SCSI-3
standard. The Tandberg SLR50 conform with the SCSI-2 standard with some SCSI-3
extensions. Communication between the Drive and the host system is undertaken via a 9 or
18-bit bidirectional bus and nine control lines.
The Drive accepts commands from the Host. The Host may read the Drive status by asking
for the transfer of special status bytes from the Drive. See Chapter 9 for a complete list of
available commands. During read and write operations, the data bytes are transferred via the
Host Bus. The transfer of each data byte is supervised by the control lines in a handshake
operation to minimize timing burden on the host controller.
For a detailed description of the hardware and software interface to the Host, see Chapters 8
and 9.