User manual SEAGATE 53073H4 SPECIFICATIONS

[. . . ] Hard Disk Drive Specifications Models: 546106, 53073H4, 52049H3, 51536H2 P/N:1493/A This publication could include technical inaccuracies or typographical errors. Changes are periodically made to the information herein ­ which will be incorporated in revised editions of the publication. Maxtor may make changes or improvements in the product(s) described in this publication at any time and without notice. Maxtor ®, MaxFax ® and No Quibble Service® are registered trademarks of Maxtor Corporation. [. . . ] An interrupt is not generated to start the first buffer fill operation. Once the buffer is full, the drive resets DRQ, sets BSY, and begins command execution. If the drive is not already on the desired track, an implied seek is performed. The data loaded in the buffer is written to the data field of the sector, followed by the ECC bytes. Upon command completion, the Command Block registers contain the cylinder, head and sector number of the last sector written. The next time the buffer is ready to be filled during back-to-back Write Sector commands, DRQ is set and an interrupt is generated. If an error occurs, Write Sector operations terminate at the sector containing the error. The Command Block registers then contain the numbers of the cylinder, head and sector where the error occurred. The host may read the Command Block to determine the nature of that error, and on which sector it happened. A Write Long may be executed by setting the Long bit in the command code. The Write Long command writes the data and the ECC bytes directly from the sector buffer; the drive itself does not generate the ECC bytes. Restrict Write Long commands to PIO Mode 0. Write Verify Sector(s) Identical to the Write Sector(s) command, except that the requested sectors are verified immediately after being written. The verify operation reads (without transferring), and checks for data errors. Any errors encountered during this operation are reported. Write Sector Buffer Allows the host to overwrite the contents of the drive's sector buffer with a selected data pattern. Sets BSY, Sets up the sector buffer for a write operation, Sets DRQ, Resets BSY and Generates an interrupt. The host may then write up to 256 words of data to the buffer. Host write commands continue to be accepted and data transferred to the buffer until either the write command stack is full or the data buffer is full. The drive may reorder write commands to optimize drive throughput. 7­4 INTERFACE COMMANDS Write Multiple Performs similarly to the Write Sector(s) command, except that: 1. Several sectors transfer to the host as a block without intervening interrupts. DRQ qualification of the transfer is required at the start of the block, not on each sector. The block count consists of the number of sectors to be transferred as a block and is programmed by the Set Multiple Mode command, which must be executed prior to the Write Multiple command. When the Write Multiple command is issued, the Sector Count register contains the number of sectors requested -- not the number of blocks or the block count. If the number of sectors is not evenly divisible by the block count, as many full blocks as possible are transferred, followed by a final, partial block transfer. [. . . ] Also known as transition detect. SEQUENTIALACCESS The writing or reading of data in a sequential order such as reading data blocks stored one after the other on magnetic tape. This is contrasted to random access of information. R RANDOMACCESSMEMORY(RAM) Memory designed so that any storage location can be accessed randomly, directly and individually. This is contrasted to sequential access devices such as tape drives. SERVOBURST A momentary servo pattern used in embedded servo control systems usually positioned between sectors or at the end of a track. SERVOCONTROL A technique by which the speed or position of a moving device is forced into conformity with a desired or standard speed or position. READ To access a storage location and obtain previously recorded data. Usually implemented such that a dynamic flux amplitude will cause a proportional electrical output from the transducer. SERVOHEAD A magnetic head designed specifically for accurately reading servo data. SERVO PATTERN A readback signal that indicates the position of a head relative to a track. READGATESIGNAL A digital input signal which causes the drive circuitry to recover data. SERVOSURFACE A recording surface in a multi-surface disk drive that only contains control information which provides timing, head position, and trackfollowing information for the data surfaces. READ ONLY MEMORY (ROM) A form of memory which cannot be changed in formal operational modes. [. . . ]