Abstract: A printing system includes print ribbon wound on first and second rotatable reels and a rotatable capstan for moving the ribbon between the first and second reels, such that ribbon is supplied from the first reel and is collected after use on the second reel. A microprocessor controls both the reel and capstan movements and computes the quantity of ribbon wound on each reel based on a known diameter of the capstan and the relationship between the number of rotational steps moved by the capstan and the number of rotational steps moved by the corresponding reel during a given time period. The microprocessor includes a random access memory in which a plurality of ramp tables are stored for controlling the movements of the reels. Each ramp table includes a speed parameter representing a particular rotational speed and an acceleration parameter representing a number of rotational steps for ramping up to and down from the particular speed, for a discrete range of ribbon diameters.