The disk drives described in this section are high-performance, random access, data storage devices designed for use in medium and large-sized computer systems. This section provides direction for operating a disk drive that has been installed. For information on installation, refer to the disk drive operations and installations manual.
Before operating a disk drive, you should be familiar with some of the controls and indicators on the drive. In the illustration below, the front panel controls and indicators are shown.
![[fig202]](img/fig202.gif)
The following table describes the functions of the disk drive controls and indicators.
| Controls | Description |
|---|
| LINE ~ SWITCH | The LINE ~ switch controls the application of AC power to the disk drive. Power is ON when the switch is in the 1 (in) position and OFF when it is in the 0 (out) position. The 1 and 0 markings correspond to international symbols presently in use.
|
| CHANNEL ADDRESS/DIAGNOSTIC SWITCH | The channel address/diagnostic switch is a 4-segment switch assembly that selects the system channel address and the tape drive self-diagnostics. The switch segments are read by the controller at the power-on sequence.
|
| RUN TIME MODE | When switch S1 is set to the RUN TIME MODE position, a series of hardware tests are performed at the power-on sequence. Following successful completion of the hardware diagnostic routines, the drive comes online.
|
| DIAGNOSTIC MODE | The DIAGNOSTIC MODE position is used for service purposes and should not be used during normal operation of the tape drive.
|
| LED DISPLAY | The front panel LED display provides a visual indication of the operational status of the tape drive. The LED display consists of a single red, green and yellow LED.
|
To manage a disk drive after it has been installed |
 |
Press the power switch to the ON position.
![[fig203]](img/fig203.gif)
The system performs an internal self-test diagnostic, which checks the key operations of the drive.
Press the LINE switch to the inner position.
![[fig204]](img/fig204.gif)
There is another self-test diagnostic, which lasts a few moments. You will then hear two sounds from the drive during the diagnostic:
The first is the spindle motor coming up to speed.
The second is the actuator performing a drive calibration and a series of seeks.
A flashing green LED indicates that the drive has opened
communication with the host computer. The drive is now ready to accept data.
For more information, refer to your disk drive's operation manual.
