| 360 / | HD | DYNAMIC MAGNETIC INFORMATION STORAGE OR RETRIEVAL |
| 69 | DF | AUTOMATIC CONTROL OF A RECORDER MECHANISM {3} |
| 71 | DF | .~ Controlling the record {3} |
| 73.01 | DF | .~.~ Speed {3} |
| 73.04 | DF | .~.~.~ Linear carrier {2} |
| 73.05 | DF | .~.~.~.~ Plural speed transport {3} |
| 73.08 | ![]() | .~.~.~.~.~ Variable speed |