Abstract: A device and process for determining the performance of a computer by determining the performance of its disc information storage system. The read-write heads of the storage system are moved by a coil and armature. There is current in the coil only during head travel. The device senses, externally of the electrical circuits within the computer and information storage system, the presence and direction of current within the coil. From this information the device may determine the amount of time and the percentage of total time the head is moving, the number of head movements, the average time or length of a head movement, and the relative time or length of individual head movements. These are negative indications of the time that no information transfer is occurring in the information storage system, and, therefor, of the efficiency of information placement on the discs in the storage units. The invention also includes the processes of doing these procedures.

Abstract: A device and process for determining the performance of a computer by determining the performance of its disc information storage system. The read-write heads of the storage system are moved by a coil and armature. The acceleration and deceleration of the arm as it is moved from one cylinder to another causes the frame and cabinet of the disc information storage unit to vibrate. The device senses one or both of these vibrations. From this information the device may determine the amount of time and the percentage of total time the head is moving, the number of head movements, the average time or length of a head movement, and the relative time or length of individual head movements. These are negative indications of the time that no information transfer is occurring in the information storage system, and, therefore, of the efficiency of information placement on the discs in the storage units. The invention also includes the processes of doing these procedures.