Abstract: The disclosed apparatus includes a cylindrical shaped surface that synchronously rotates with a tape reel. Reflective material is patterned on this surface to form first, second and third tracks of bits running parallel to each other around the surface. A pair of light beams are aligned with the first and second tracks when a file protect reel is inserted in the tape reel, whereas the same pair of light beams are aligned with the second and third tracks when the tape reel does not have a file protect ring inserted therein. A light sensing circuit converts the portion of the light beams that is reflected from the aligned tracks into a pair of logic signals representative thereof. When the tape is moving in a predetermined direction, another circuit sets a bit in response to the logic signals as an indicator of which tracks are aligned with the light beams. Subsequently, the logic signals and the bit are used to indicate the amount of tape that is unwound from or wound onto the tape reel.

Abstract: The disclosed tape transport mechanism includes within a cabinet, a pair of tape reels, a read/write head, a capstan, a first vacuum column, and a second vacuum column. Each of the vacuum columns have an elongated body, an open end for receiving magnetic tape from a respective one of the tape reels, and a closed end. The first vacuum column is positioned substantially perpendicular to the second vacuum column; and the open end of the second vacuum column is positioned spaced apart from the closed end of the first vacuum column. Further, the capstan is positioned at the open end of the first vacumm column; and the read/write head is positioned along the body portion of the first vacuum column. Each of the vacuum columns lie along a respective one of the cabinet's sides, and no direction changing tape rollers lie anywhere between the vacuum columns.