| 360 / | HD | DYNAMIC MAGNETIC INFORMATION STORAGE OR RETRIEVAL |
| 69 | DF | AUTOMATIC CONTROL OF A RECORDER MECHANISM {3} |
| 75 | DF | .~ Controlling the head {3} |
| 77.01 | ![]() | .~.~ Track centering {2} |
| 77.02 | DF | .~.~.~> Rotary carrier {5} |
| 77.12 | DF | .~.~.~> Elongated web carrier (i.e., tape) {1} |