Method of recording in a disk memory and disk memory system
First Claim
1. A method of writing and reading numerical information in a mass memory comprising a plurality of disk units (3), each disk unit being capable of containing one or a plurality of disks (7), said mass memory being controlled by at least one disk controller, each word of numerical information comprising a plurality of bits and being associated with a logical address, characterized in that at the time of the transfer of information to or from disk units (3), the bits making up one word of information are transmitted simultaneously, each bit being allocated to a disk unit associated with the position of said bit in said word, in order to be written or read synchronously with the other bits of the same word at a physical address which is a univocal function of the logical address of said word of information, said physical address defining, for each disk unit, the effective location where said bit will be written or read, that is, defining the disk of said unit, in the case where the unit includes more than one disk, a number of a track of said more than one disk and the location of said bit on said track, said method being further characterized in that for writing a block of information, that is, a sequence of words of information associated with a block address and arriving at each disk unit in the form of a sequence of bits associated with the same block address, each bit of said sequence is first temporarily recorded in a memory associated with said each disk unit, and then physically recorded on a disk of said unit and in that for reading a block of information from said disk, a reverse operation is performed, said method being further characterized in that before transferring to said disk the sequence of numerical information transmitted from said memory associated with said disk unit, longitudinal error detection or correction bits (Kli-Kyi) are calculated and added to said sequence, and in that before writing into the memory the sequence of numerical information coming from said disk, an operation of detecting longitudinal error and correcting them if necessary is effected.
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Accused Products
Abstract
A method of recording numerical information in a plurality of disk units, in which the bits of each word of numerical information are transmitted simultaneously, each bit being allocated to a unit associated with the weight of that bit in that word, and a memory system for implementing the method, including a main controller (2) provided with a selector enabling the distribution and synchronization of the information signals.
221 Citations
48 Claims
- 1. A method of writing and reading numerical information in a mass memory comprising a plurality of disk units (3), each disk unit being capable of containing one or a plurality of disks (7), said mass memory being controlled by at least one disk controller, each word of numerical information comprising a plurality of bits and being associated with a logical address, characterized in that at the time of the transfer of information to or from disk units (3), the bits making up one word of information are transmitted simultaneously, each bit being allocated to a disk unit associated with the position of said bit in said word, in order to be written or read synchronously with the other bits of the same word at a physical address which is a univocal function of the logical address of said word of information, said physical address defining, for each disk unit, the effective location where said bit will be written or read, that is, defining the disk of said unit, in the case where the unit includes more than one disk, a number of a track of said more than one disk and the location of said bit on said track, said method being further characterized in that for writing a block of information, that is, a sequence of words of information associated with a block address and arriving at each disk unit in the form of a sequence of bits associated with the same block address, each bit of said sequence is first temporarily recorded in a memory associated with said each disk unit, and then physically recorded on a disk of said unit and in that for reading a block of information from said disk, a reverse operation is performed, said method being further characterized in that before transferring to said disk the sequence of numerical information transmitted from said memory associated with said disk unit, longitudinal error detection or correction bits (Kli-Kyi) are calculated and added to said sequence, and in that before writing into the memory the sequence of numerical information coming from said disk, an operation of detecting longitudinal error and correcting them if necessary is effected.
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4. A method of writing and reading numerical information in a mass memory comprising a plurality of disk units (3), each disk unit being capable of containing one or a plurality of disks (7), said mass memory being controlled by at least one disk controller, each word of numerical information comprising a plurality of bits and being associated with a logical address, characterized in that at the time of the transfer of information to or from the disk unit (3), the bits making up one word of information are transmitted simultaneously, each bit being allocated to a disk unit associated with the position of said bit in said word, in order to be written or read synchronously with the other bits of the same word at a physical address which is a univocal function of the logical address of said word of information, said physical address defining, for each disk unit, the effective location where said bit will be written or read, that is, defining the disk of said unit, in the case where the unit includes more than one disk, a number of a track of said more than one disk and the location of said bit on said track,
said method being further characterized in that for writing a block of information, that is, a sequence of words of information associated with a block address and arriving at each disk unit in the form of a sequence of bits associated with the same block address, each bit of said sequence intended for being recorded in the corresponding disk unit is first inscribed, at an address in memory which is a univocal function of the block address and of the place of the bit in said sequence of bits, into a direct access memory associated with said disk units, and when said sequence of bits has been entirely inscribed into said memory, the numerical information then contained in said memory is read in sequence and transmitted in series in order to be recorded on a track of one of the disks of said unit, said disk and said track of said disk being determined as a function of said block address, the memory address of the first bit transmitted being determined as a function of the number of the first sector of said track encountered by the recording head, the sequential reading of said memory being effected in accordance with a cyclical sequence, and in that for reading a word of information associated with a given logical address, the bits comprising this information beginning at the set of memories associated with said disk units at memory addresses which are a function of the logical address, are synchronously read immediately, if the information is present in the set of memories or, in the contrary case, after retranscription into each memory of the entirety of the numerical information contained on the track associated with said logical address, said retranscription being effected beginning at the first sector of said track encountered by the reading head.
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5. A method of writing and reading numerical information in a mass memory comprising a plurality of disk units (3), each disk unit being capable of containing one or a plurality of disks (7), said mass memory being controlled by at least one disk controller, each word of numerical information comprising a plurality of bits and being associated with a logical address, characterized in that at the time of the transfer of information to or from the disk units (3), the bits making up one word of information are transmitted simultaneously, each bit being allocated to a disk unit associated with the position of said bit in said word, in order to be written or read synchronously with the other bits of the same word at a physical address which is a univocal function of the logical address of said word of information, said physical address defining, for each disk unit, the effective location where said bit will be written or read, that is, defining the disk of said unit, in the case where the unit includes more than one disk, the number of a track of said more than one disk and the location of said bit on said track, and
further characterized in that each bit of said word of information is first temporarily recorded in a memory associated with said disk and then is physically recorded on a disk of said unit, and in that for reading a word of information from said disk, a reverse operation is preformed, and further characterized in that before recording onto a disk track the block of numerical information transmitted beginning at the memory associated with a disk unit, longitudinal error detection or correction bits (K1i -Kyi) are calculated and added to said block of numerical information, and in that before writing into the memory the numerical information coming from one track, an operation of detecting longitudinal errors and correcting them if necessary is effected.
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13. A memory system, including a plurality of disk units (3) connected to the exterior via first lines (D1, A1, C1) for transmitting data, address and control signals, characterized in that said disk units (3) are controlled by a main controller (2) cooperating via second lines (D2, A2, C2) for transmitting data, address and control signals with a plurality of disk controllers (4), each of which controls one disk unit (3) containing one or a plurality of disks (7), and in that said main controller (2) includes means (21, 23, 25, 29, 30) for synchronizing a simultaneous transfer of bits forming each word of information to be written or read in said disk units (3) and means for commanding said disk controllers (4) to write or read simultaneously, each disk controller (4) thus validated being able to process, for each word of information, a single bit of said word of information and to transmit or receive said bit via a line (8) connected to the main controller,
said memory system being further characterized in that said main controller including means (21, 25, 26, 31) for determining, based on a logical address associated with a word of information to be read or written, a logical disk address being a logical disk number, a logical track number and a complementary address, said logical disk address being transmitted to each disk controller via said lines, and means for giving the order to read or write to said controllers via said lines, and in that each disk controller (4) includes means for writing the information received over its line into the associated disk unit (3), at a physical address which is a univocal function of the logical disk address and means for reading in this disk unit the information recorded at said physical address and for transmitting said information over the line.
Specification