| 369 / | HD | DYNAMIC INFORMATION STORAGE OR RETRIEVAL | 
| 176 | DF | DYNAMIC MECHANISM SUBSYSTEM {8} | 
| 215 | DF | .~ Having power driven transducer assembly {6} | 
| 219 |  | .~.~ With drive transverse to storage track during storage or retrieval {4} | 
| 220 | DF | .~.~.~> Controlled by transducer assembly support | 
| 221 | DF | .~.~.~> With additional drive (e.g., scanning, restoring, or return) | 
| 222 | DF | .~.~.~> Having pivoted tone arm | 
| 223 | DF | .~.~.~> By lead screw |