Abstract: A method of reading multimedia information which is capable of realizing optimal data access in consideration of the type and content of data to be accessed and the relationship to other data during access. The method involves reading first and second information from a storage medium, multiplexed with each other, where response time guarantee is of relatively higher importance for the first information and reliability is of relatively higher importance for the second information. Management of the read time is performed on both the first and second information. A plurality of processing methods are pre-defined as error countermeasure methods for the case where an error occurs in information read out when reading the first or second information in units of predetermined amounts. When reading information, one of the plurality of error countermeasure processing methods is selected and set for use.

Abstract: An apparatus for recording and/or reproducing a data signal on or from a disk shaped recording medium having a special track in which control information is prerecorded. The apparatus reproduces the control information at first when the disk is mounted therein, and stores the reproduced control information in a memory. A rotation control cirucit for controlling the rotation of the recording medium is supplied with a control signal based on the control information read out of the memory and controls the rotation of the medium such that the linear velocity of the rotation is of a predetermined constant value according to the control information.

Abstract: A method of reducing the DC component in a digital information signal comprised of a plurality of 8-bit data words by converting each of the 8-bit data words to a 10-bit data word, comprises the steps of: selecting the 10-bit data words having a sequence of no more than two bits both at the logic level "1" or "0" from both boundaries of the 10-bit data words; classifying the selected 10-bit data words into a first group consisting of 10-bit data words having five logic level "1" bits, a second group consisting of 10-bit data words having six logic level "1" bits, and a third group consisting of 10-bit data words having four logic level "1" bits, with the third group being formed by inverting the 10-bit data words in the second group; and further assigning the 8-bit words alternately to the 10-bit words in the second and third groups when such 8-bit words correspond to previously assigned 10-bit words having six logic level "1" bits and assigning the remaining 8-bit words to the 10-bit words in the first group