Signal processing apparatus and a data recording and reproducing apparatus including local memory processor

A data recording and reproducing apparatus, comprising:

• a recording media;
• a controller coupled to an external processing unit;
• a recording and reproducing head controlled by the controller for recording information on the recording media and for reproducing information from the recording media;
• a processor coupled to the controller;
• a read/write amplifier for exchanging recording and reproducing information with the recording and reproducing head;
• a recording circuit for outputting recording information to the read/write amplifier;
• and
• a reproducing circuit, including a memory, for receiving as an input a signal from the read/write amplifier, detecting reproducing information in the signal from the read/write amplifier and supplying as an output a signal representing the detected reproducing information,
• wherein the memory stores the signal from the read/write amplifier, and
• wherein the reproducing circuit comprises:
• a selector which selects a signal output from the memory or the signal output from reproducing circuit.

A signal processing apparatus, comprising:

• a reproducing means for receiving an analog signal;
• analog-to-digital (A/D) conversion means for converting the analog signal into a digital signal;
• storage means for storing the digital signal;
• detecting means for detecting the digital signal;
• and
• selection means for selecting an output from the storage means or an output from the A/D conversion means.