Abstract: A sled motor controlling method for shifting the position of an optical pickup a CD-ROM drive is disclosed. According to the inventive method, the number of tracks from an initial position of a pickup to a target position are counted. A timer interrupt, of a timer inside the CD-ROM, is enabled for acceleration to and rotation at constant speed of a sled motor which moves the pickup. The ennoblement of the timer interrupt is based on a number of reference clock pulses which correspond to the number of tracks to be traversed. A determination is made whether the pickup is approaching the target position. If it is determined that the pickup is approaching the target position, a timer interrupt is enabled for deceleration of the sled motor. Then, all timer interrupts are disabled if it is determined that the pickup has reached the target position.

Abstract: A compact disk, a high-speed searching method of the compact disk, and a recording method which corresponds to the high-speed searching method is provided. The compact disk includes a lead-in area and e program area. The lead-in area contains table-of-contents information which includes the number of recording tracks recorded on the disk and address information relating to each track. The program area contains index-table information which includes index numbers and starting addresses for a plurality of programs recorded on the disk. Furthermore, the plurality of programs are recorded in the program area according to its corresponding index number. Specifically, the programs are recorded from the innermost circumference to the outermost circumference of the disk in a tree structure based on the index numbers.