| 360 / | HD | DYNAMIC MAGNETIC INFORMATION STORAGE OR RETRIEVAL |
| 69 | DF | AUTOMATIC CONTROL OF A RECORDER MECHANISM {3} |
| 71 | DF | .~ Controlling the record {3} |
| 74.1 | ![]() | .~.~ Stopping or reversing {4} |
| 74.2 | DF | .~.~.~> Responsive to reel rotation |
| 74.3 | DF | .~.~.~> Responsive to tape tension |
| 74.4 | DF | .~.~.~> Responsive to magnetic recorded signals |
| 74.5 | DF | .~.~.~> Responsive to physical property of record {2} |