Abstract: An optical information storage medium (e.g., disk) has an arrangement of optically detectable marks in a uniform angularly offset, polar array wherein each mark carries timing, tracking and addressing information.

Abstract: A drive apparatus for an optical disc read system. An interface is provided to a host controller for reading out data on a compact disc. The read out data is converted from parallel to serial format, and transmitted with a clock stream to the host controller. Host controller commands are transmitted to the drive apparatus which recognizes the command as either allowable or non-allowable. The interface provides signalling to the host controller of drive error conditions, spin up/non-spin up conditions, and non-allowable command situations for the controller.

Abstract: Apparatus permits the use of a compact audio disc to provide digital data information other than audio signals without requiring a change of format of the audio disc and involving only minor changes to existing digital audio disc playback apparatus. Data signals are rearranged to permit searching of the data information in a fashion compatible with existing digital audio disc playback apparatus and maintaining consistency with respect to signal format and signal processing, such as error correcting and recording data format presently used in compact digital audio discs.

Abstract: Apparatus permits the use of a known optical compact audio disc for providing a larger memory capacity so that data other than audio data can be reproduced therefrom while maintaining consistency with respect to signal format and signal processing, such as error correcting methods and recording data formats and the like, by providing write clock signals and read-out clock signals for reading into and out two memories the main digital data signal by using a subdigital data signal that is recorded on the disc along with the main digital data and which is reproduced from the disc at the same time as the main data in order to provide addressing of the main digital data on a more accurate level and with finer resolution, and a control system searches a playback location of the main digital data based upon the subdigital data as read out from the buffer memory, in which subdigital data has been written by the write clock signal.

Abstract: Information is written in consecutively arranged sectors of a record carrier body, preferably an optical disc. The information is written interleaved into the record carrier body. The information is read directly after writing for the purpose of verification. An identifier, indicating a previously correctly inscribed sector is added to the information to be written in a sector. The added identifier enables the transfer of only the correctly written information during a read operation.