Abstract: A digital LRU network in which a use value in a chronology register always appears to be increasing; it is incremented for each access to a different data block currently represented in an active LRU array and this use value is copied into an index for that block in an active use-value array. Special circuits are provided to maintain the appearance of continuously increasing use values. At the start of each array search, the special circuits check the chronology register to determine if its use value is nearing its highest registerable value by testing its two high order bits for 1's. If so, the chronology register is set to 100...0, which is higher than any use value in the active array, after the use values in the active array are shifted one bit position to the right by writing them into corresponding positions in another array, which then becomes the active array. The right shift drops the low-order bit in the use values and sets the high-order bit to zero.