A Sonar-Coder was a type of technology used in The New Adventures of He-Man.
A Sonar-Coder was a small Priman device for storing data. Master Sebrian once equipted Adam of Grayskull with a Sonar-Coder. His mission was to infiltrate the Mutant Mothership, point the device at the control panel for the tractor beam, and it would take the readings the Scientists of Primus needed to perfect the Reverse Particle Enhancer.