Abstract: Apparatus for determining the next data word of a requested block of data words in interlaced rotating mass memories to enable transfer of the requested block from other than the first word in the block to reduce the effective average latency. The system assumes the use of a memory storage element which is read in a serial rotational fashion (e.g., drum, disk, charge coupled device, etc.). The present invention compares the address of the data requested by a Central Processor Unit (CPU) with the address from the interlaced memory storage element that indicates its present rotational position. From these addresses, it computes the address of the next accessible cell within the requested block and transfers that address to the CPU to enable it to access the requested block at the earliest possible time.

Abstract: A method and an apparatus for encoding and decoding a binary digital data signal is disclosed. An input signal that is to be encoded for transmission is shifted through a serial shift register with the bits in the stages of the shift register at each of the successive shift periods being used to define a binary coded addressable location in an associated memory. The memory has stored in each of its addressable locations a further binary code that when addressed by the shift register produces, as an output, a binary True or Complement signal which through a True/Complement generator couples the True or the Complement of the input signal to the transmission medium. The receiving end of the transmission medium has a similar arrangement of shift register, memory and True/Complement generator that decodes the received encoded transmitted signal.