MAGNETOSTRICTIVE DELAY LINE MEMORY FOR TRANSIT 4A,

The paper discusses the magnetostrictive delay line portion of the entire memory system. The decoder has as an input the video output of the command receiver. It is sensitive to an audio frequency tone. During the memory load, the first audio tone burst will cause the decoder to send a clear signal to the magnetostrictive delay line memory. At the termination of the first audio tone burst, the decoder will send a timing signal to the magnetostrictive delay line memory for the insertion of a timing marker into the memory. During the remaining load process an audio tone at the input to the decoder will be interpreted as a 1. The absence of an audio tone will be interpreted as a zero. The timing marker inserted in the magnetostrictive delay line memory will re-appear every 2,048us to sample the output of the decoder until the memory is loaded. This system of loading the memory under control of the satellite timing circuitry requires that the transmission bit rate at the injection station be carefully synchronized with the memory data rate. The data readout rate from the memory is also under control of the satellites stable oscillator and is not dependent on the exact delay period of the magnetostrictive lines.