A disc drive system, such as a magnetic or optical recording and/or
playback system, for low-data rate applications implements one or more
circuit operations, such as read signal detection and related servo
functions, as software-based digital signal processing steps in a
dedicated software-based processor. The drive system incorporates
increased buffering, modified input sample processing techniques,
multiplexing of processing functions, and modified automatic gain control
techniques to allow circuit operations to be performed with
software-based digital signal processing techniques.