| 369 / | HD | DYNAMIC INFORMATION STORAGE OR RETRIEVAL |
| 176 | DF | DYNAMIC MECHANISM SUBSYSTEM {8} |
| 215 | DF | .~ Having power driven transducer assembly {6} |
| 216 | ![]() | .~.~ Having tone arm set-down control {1} |
| 217 | DF | .~.~.~> By disc sensing (e.g., by sensed disc or hole size) |