Zoned recording embedded servo disk drive having no data identification fields and reduced rotational latency

A zoned recording fixed-block architecture embedded servo disk drive comprising:

• a rotatable data recording disk having a plurality of generally concentric data tracks divided into a plurality of radially-spaced zones and a number of generally equally angularly-spaced servo sectors extending generally radially across the zones, each of the tracks in the plurality also having an index associated with it for signaling the beginning of the track and a number of data sectors but no identification (ID) regions containing information that uniquely identifies the data sectors, each of the tracks being divided into a number of identical track segments, each of the identical track segments consisting of n servo sectors and n data regions, each data region being located between circumferentially adjacent servo sectors, the n data regions being divided into m data sectors, where m may vary from zone to zone, at least one of the m data sectors being split into data sections by a servo sector;
• a recording head that reads information in the servo sectors and writes and reads user data in the data sectors and is movable across zones;
• a servo sector counter, responsive to the track index signal, for counting servo sectors as the disk rotates past the head;
• memory storage for storing track segment format information including, for each of the m data sectors within a segment, the data sector number from the start of the segment;
• a data sector counter coupled to the memory storage for counting data sectors, the data sector counter being preset by receipt of the track index signal;
• sector logic circuitry responsive to the count from the servo sector counter and to the count from the data sector counter for retrieving track segment format information from the memory storage and for locating, from the track segment format information and without use of ID regions, a data sector where user data is to be read or written;
• read/write circuitry coupled to the sector logic circuitry and to the recording head for causing the head to read or write at the located data sector;
• and
• wherein, after movement of the head from a first zone to a second zone, the data sector counter is preset by the stored data sector number corresponding to the data sector that immediately follows the first servo sector read by the head after the head is moved to the second zone;
• whereby the head may read or write in a data sector in the second zone prior to the data sector counter being preset by the track index signal in the second zone.