| 360 / | HD | DYNAMIC MAGNETIC INFORMATION STORAGE OR RETRIEVAL |
|
| 69 | DF | AUTOMATIC CONTROL OF A RECORDER MECHANISM {3} |
| 75 | DF | .~ Controlling the head {3} |
| 78.01 | DF | .~.~ Track changing {2} |
| 78.04 |  | .~.~.~ For rotary carrier (e.g., disc) {8} |
| 78.05 | DF | .~.~.~.~> Coarse and fine head drive motors |
| 78.06 | DF | .~.~.~.~> Specified velocity pattern during access {1} |
| 78.08 | DF | .~.~.~.~> Specified spatial pattern during access |
| 78.09 | DF | .~.~.~.~> Including model of servo system or element |
| 78.11 | DF | .~.~.~.~> Including nonmagnetic position sensing |
| 78.12 | DF | .~.~.~.~> Including particular head actuator {1} |
| 78.14 | DF | .~.~.~.~> By recorded servo reference or address signal |
| 78.15 | DF | .~.~.~.~> Drum |