User's Guide

Chapter 2 Installing Internal Tape Drives
Media Recognition System (DDS-4 Drives Only)
DDS-4/DAT 72 User’s Guide 20
Media Recognition System (DDS-4 Drives Only) 2
Settings:
Switch 3 ON = Enable MRS (default)
Switch 3 OFF = Disable MRS
Using non-DDS media may appear to give satisfactory results, but the
inferior specifications of such media can cause data-integrity problems.
To avoid these problems, the internal tape drive provides a media-
recognition system (MRS) feature that determines whether tape
cartridges conform to the DDS tape standard.
By default, switch 3 is set to ON, enabling MRS. With this setting, the
drive:
• Reads from and writes to MRS media.
• Reads from but does not write to non-MRS media.
To disable MRS, set switch 3 to the OFF position. With this setting, the
drive reads from and writes to MRS and non-MRS media.
Power-On Self-Test 2
Settings:
Switch 4 ON = Drive performs Power-On Self-Test (default)
Switch 4 OFF = Drive does not perform Power-On Self-Test
Switch 4 enables or disables the Power-On Self-Test diagnostics that the
drive performs when powered on. By default, the drive responds to SCSI
commands only after it successfully completes the Power-On Self-Test
(about 5 seconds). To prevent the drive from performing the Power-On
Self-Test when powered-up, set switch 4 to the OFF position.
Note: Switch 3 is reserved on internal DAT 72 drives.