Abstract: A method for determining the authenticity of an item, the method comprising: receiving, by an item, a seed; storing the seed in a block of non-volatile memory in the supply item follower component; calculating, by the item follower component, an output of a cryptographic function with the input based on the seed and storing the output in the block of non-volatile memory; iteratively calculating, by the item, the outputs of the cryptographic function wherein for each iteration the input for the cryptographic function is based on the seed and all previous outputs, and for each iteration storing the output in the block of non-volatile memory; and determining the authenticity of the item based on a selected output of the cryptographic function of the item, the selected output being one of the outputs stored in the block of non-volatile memory.

Abstract: A method for calibrating a printhead includes printing a test pattern, scanning the test pattern to obtain calibration data, performing an ink drop velocity optimization for the printhead using the calibration data, and determining a bi-directional offset based on the calibration data.

Abstract: A method of performing printhead maintenance firing in an ink jet printer that has a printhead carrier that carries an ink jet printhead, the ink jet printer having a waste ink receptacle, includes the steps of decelerating the printhead carrier from a first velocity after printing print data; and controlling a firing of the printhead during the decelerating in accordance with maintenance data so that ink droplets ejected from the printhead during the decelerating are received by the waste ink receptacle.