Abstract: A magnetic bubble memory chip comprises minor loops of a folded structure for storing information in the form of magnetic bubble domains, and input and output tracks for transferring the information into and out of the minor loops. The input and output tracks have a pattern repetition period that is four or more times as large as a fundamental period of each of the minor loops.

Abstract: Apparatus for making stereophonic recordings using multiple microphones, and playing back the recordings through multiple speakers, wherein each of the microphones is mounted with a corresponding speaker in a single enclosure. For convenience, the microphones and speakers may be connected by flexible leads to a separate record-playback unit, and, since each microphone is permanently located immediately adjacent a corresponding speaker, the apparatus is capable of accurately reproducing the recorded sounds in their apparent locations by providing the same stereophonic separation for recording as for playback.