Last Wrap Detection for Tape Transport
Original Publication Date: 1982-Aug-01
Included in the Prior Art Database: 2005-Feb-09
A method commonly used in tape storage systems to detect the last wrap of tape wound on a machine reel during the unload operation involves the use of a light emitting diode, phototransistor and associated detection circuits. These detect presence of tape in the tape path by means of the tape interrupting a beam of light. An improved method proposed here uses hardware already present on the machine (namely, tachometers and associated circuitry) along with a new microcode algorithm to complete this function. A flow chart is illustrated in the figure.