a write signal processing circuit 14 the signal processing circuit 14 converts the input data into signals with a format suitable for storage on a magnetic medium 16 the medium 16 is typically a rotating disk a u201c floppy u201d disk or a tape with magnetic coatings a write head 18 stores the signals on the medium 16 as a series of variations in the magnetic flux of the medium 16 the write head 18 is controlled by a write control circuit 20 which supplies signals to the write head 18 to control its position with respect to the medium 16 a read head 22 retrieves the variations in the magnetic flux that are stored on the medium 16 a read control circuit 24 supplies signals to the read head 22 to control its position with respect to the medium 16 the read head 22 provides a stream of data to a detector circuit 26 the detector circuit 26 detects the data from the data stream and outputs the data the detector 26 must be able to detect the data in the presence of intersymbol interference u201c isi u201d noise prior art detector circuits have employed the maximum likelihood sequence u201c mls u201d estimation algorithm or peak detection techniques the mls algorithm analyzes a sequence of consecutive data and determines the output data based on the sequence peak detection techniques identify analog peaks.