A system for testing hard disks includes a hard disk testing device and a computer. The display sub-systems that utilize the selection by panning and zooming of a portion of the acquisition record for viewing are supplied with the acquisition record portion of interest, and with an associated horizontal position value that originates with trigger interpolation and that may be subsequently modified by panning. As a result, the individual effectors possess decision-making ability and, for purposes of this invention, may be referred to as intelligent effectors.