The present application discloses a memory circuit having a first data line configured to carry a first data line signal and a second data line configured to carry a second data line signal. The web-guiding structure includes an exterior surface having a pattern of recesses formed into the exterior surface, wherein the web of media travels past the web-guiding structure with a first side of the web of media contacting at least some non-recessed portions of the exterior surface of the web-guiding structure. The rotation speed estimation unit includes an error calculation unit that calculates an error related to rotation of the electric motor and an estimated corrected rotation speed calculation unit that calculates an estimated corrected rotation speed by taking the error as input and correcting the estimated rotation speed.