Abstract: A method for fetching data in the form of a group of source bits (bytes, words, etc.) from computer memory and providing successive portions of the group to a computer process. An indicator such as a bit string is loaded into one location of a register and the group of source bits is loaded into another location in the register. The contents of the register are then rotated to move successive portions of the group into a register location where the portions can be accessed for a process. Tracking the processing of the successive portions of the bit group is handled efficiently in a loop through monitoring of the indicator, which "walks" through the register concurrently with movement of the successive portions of the source bit group. When the indicator bit has returned to its initial register location, the processing of the group of source bits is complete.