Topic 3 Maintenance Requirements

Figure 9-22.—A magnetic tape cartridge. standard cartridge uses 600 feet of 1/4-inch tape. Instead of reflective markers, holes punched in the tape are used to indicate BOT/EOT. The unit contains four read/write heads. Data may be written on or read from four addressable tracks (0, 1, 2, or 3). Separate data maybe stored in each track, or tracks may be used as a continuation of the previously selected track. Data is stored serially one bit at a time down the length of the track. Up to 60 megabytes of data may be stored on one 600-foot cartridge. Cartridge units are slower than standard tape drives, but the cartridges are more rugged and easily transported. In addition, the cartridge unit has less moving parts than the standard tape drive, which contributes to increased unit reliability and , maintainability. TOPIC 3—MAINTENANCE REQUIREMENTS Preventive maintenance of magnetic tape devices consists of performing mechanical and electrical alignments and testing the tape units using several different maintenance programs. ALIGNMENT Magnetic tape units require many mechanical and electronic adjustments/alignments. Some of these adjustments are required only during unit installation. Others must be done when a faulty component or assembly is removed and/or replaced. Still others are needed because of normal equipment usage (wear and tear). Alignment checks or adjustments required on a periodic basis are covered by the Planned Maintenance System (PMS) Maintenance Index Page (MIP) and Maintenance Requirement Cards (MRCs) that apply to the unit you are maintaining. You may find nonperiodic adjustment procedures or technical specifications for periodic alignment checks in the technical manual for the magnetic tape device in your system. 9-19