Abstract: Disclosed are backpack and carrier assemblies adapted to be worn by and partially supported or stabilized by the upper torso of the user. A pivotal coupling is provided with the backpack portion at or above the center of the gravity of the backpack so that the backpack is free to swing from side to side behind the hips of the user and to swing about the coupling. Low friction blocks, pads, rollers or surface are provided near the lower extremity of the backpack and between the backpack and the hip and pelvic region of the user in order to reduce frictional forces and facilitate the side-to-side movement.

Abstract: A keyboard teaching device for the self-instruction of a student of keyboard musical instruments is provided which enables the student to correlate the positions of the keys on a musical instrument keyboard with the positions of the notes on a musical scale. A keyboard having a plurality of keys corresponding to the notes of a musical scale for generating a first set of control signals in an initialization or set-up mode and key-note correlation signals in an instruction or game mode, at least one storage means having a predetermined combination of logical signals providing a source for a random sequence of one or more notes over a predetermined range in the game mode for generating a second set of control signals in response to the actuation of one or more keys in either mode and a means for generating audio tones and displaying video images in accordance with the first and second sets of control signals enables the student to visually and audibly check his or her selection of one or more of the keys.

Abstract: An asynchronous interface between a data input system (computer) and the keyboard multiplexer of an electronic musical instrument (digital organ) includes a pair of RAMs. The interface synthesizes the multiplexed keyboard data stream of the digital organ by swapping read and write operations between the two RAMs. Predetermined key data (WRITE DATA) provided by the computer is written into one RAM during a WRITE interval while key data (READ DATA) previously written into the other RAM is sequentially read out of the latter RAM. The WRITE DATA designates those keys on the organ keyboard which are to be simulated as being active. The read and write operations are alternately applied to each RAM. If the READ DATA matches the key code assigned to a key on the keyboard, the appropriate note is sounded by the organ. The two RAMs can actually be two segregated portions of a single memory.