1. In a convolutional code decoder for decoding data which coalesces into a predetermined plurality of possible states, said data occurring at branches corresponding to data states in a sequence, and including correlation means having a data input indicative of a message digit comprising received convolutional data and in which branch metrics are utilized to update path metrics and in which magnitudes of survivor path metrics are compared to determine the most likely sequence of received data, the improvement wherein said correlation means comprises a trellis connection computer having a first storage means associated with one possible data state of a received sequence, said first storage means being coupled to be addressed by the data input and being preset to provide an output address indicative of branch metrics associated with the likelihood of data input entering the state from one data path; second storage means for providing an updated path metric; third storage means for storing a path metric of said data path; means coupling said path metric and said output address to provide addresses to said second storages means; said second storage means being preset to provide an updated path metric in response to said address, and means for replacing said path metric with said updated path metric in said third storage means whereby said third storage means is set to address said second storage means after the occurrence of a next data input.