Disk Drive Access Mechanism Zero Stop
Original Publication Date: 1985-Feb-01
Included in the Prior Art Database: 2005-Feb-18
This article describes a method of establishing a reference stop for a diskette drive head access mechanism. When a diskette drive is powered on, a command is given to step the access mechanism through its full travel to track 0. A physical stop is provided at a fixed distance past track 0 to limit access mechanism travel. If the access mechanism is at an intermediate position at power-on, then it will step to the rear until the zero stop is reached. The stepper motor will then slip phase as further steps are attempted. After the number of steps equating to full travel are given, then the motor is energized on phase 1 and the carriage is at track 0. In this implementation, the access mechanism zero stop is provided as part of the motor assembly, as shown in the figure.