Abstract: A method and apparatus for maximizing the data storage capacity of a floppy diskette. The present invention provides a format that reduces the inter-sector gap between adjacent sectors on each track to eight bytes. The storage space gained from the reduction in gap size is used to add additional sectors to each track on the diskette, thereby providing a total of twenty-one sectors per track. Because the gap between sectors is reduced to such a small size, the disk controller may not be able to process the data from one sector before the adjacent sector is to be read. Therefore, sectors are arranged on each track in a 2:1 interleave arrangement, such that one sector separates consecutively-numbered sectors. Additionally, to increase performance, the end of the last sector on each track is offset from the beginning of the first sector on the next track by four sectors.

Abstract: An improved method is disclosed for placing continuous media data in a memory storage disk that will increase the disk operating efficiency and increase the number of users in a service round.

Abstract: In a multitrack recording arrangement in which information may be recorded in or reproduced from a plurality of adjacent tracks simultaneously and in which the plurality of adjacent tracks are longitudinally partitioned into segments referred to as tape frames, each tape frame being formed of a plurality of laterally adjacent track segments referred to as track frames, each tape frame is assigned to one of a plurality of channels, one channel of information being recorded in each n-th tape frame.

Abstract: A method is described which provides various new data storage system capabilities by using data storage structures within industry standard (or other pre-existing) formats used with data recording devices employing removable media. The data storage structures used by the present method comprise formats which contain regions previously marked as "contents of this region are not of interest" or marked as "no data was recorded within this region". These data storage structures are thus transparent to present data recording devices so as not to disrupt their data processing functions. However, the data storage structures are available to be used by new data recording devices (or old devices that have been updated) so that new data embedded therein may be used to enhance the functionality of the system which utilizes the data storage structures.

Abstract: A storage control system with auxiliary storages includes a system information generator which determines an optimum process data length and gap value to minimize switching between cylinders or tracks in reading/writing of data based on device information obtained from a specified auxiliary storage. Based on the determined optimum process data length and gap value, a data area generator secures a data area on the specified auxiliary storage. The system information generator determines the process data length and the gap value so that the process data length is less than the size of a track in the specified auxiliary storage and satisfies either of the following conditions: (a) Size of a track can be divided by the process data length; or (b) Sum of the process data length and the gap value is a value obtainable by multiplying the track size by an integer.

Abstract: A method is described which provides various new data storage system capabilities by using data storage structures within industry standard (or other pre-existing) formats used with data recording devices employing removable media. The data storage structures used by the present method comprise formats which contain regions previously marked as "contents of this region are not of interest" or marked as "no data was recorded within this region". These data storage structures are thus transparent to present data recording devices so as not to disrupt their data processing functions. However, the data storage structures are available to be used by new data recording devices (or old devices that have been updated) so that new data embedded therein may be used to enhance the functionality of the system which utilizes the data storage structures.

Abstract: A method and apparatus of reproducing and recording data stored in a plurality of tracks of a memory. A recording and reproducing head reproduces data from at least one of a plurality of tracks of a disk-shaped recording medium. The reproduced data is stored in a memory and rewritten. Data is read out of the memory and controllably supplied to a recording operation of the recording and reproducing head so that data of every track read out from the memory is recorded on the disk-shaped recording medium. In a preferred embodiment, the reproduced data is stored, rewritten read out from the memory in response to an index signal representing a starting portion of a track and then recorded on a magnetic floppy disk.

Abstract: The invention relates to a disk track emulation system and method, whereby, when a disk device is replaced by a new disk device having a disk track with a data format different from that of the conventional device, a program in a conventional host device can be used as it is, in the same way as in the conventional disk device, without reforming the program. To maintain the a compatibility, using the characteristic that the data format is divided by a unit called a cell having a constant number of bytes, and writing, into a home address area and a count area in the new data format, cell position data with the new data format, and compatible cell position data with respect to the conventional data format in which the compatibility should be maintained.

Abstract: Disclosed is a circuit for detecting an unrecorded portion of a recording medium, which has a window counting portion (10) for receiving an input signal, for recognizing if the input signal comes from an unrecorded portion of the recording medium and for counting a predetermined time to generate a window signal. The circuit also has a sync signal generator (20) which is enabled by the window signal, in which, if the number of pulses of the input signal equals or exceeds a predetermined number, the generator recognizes that the current input signal comes from a data region of the recording medium and therefore generates a sync signal. If the number of pulses of the input signal is less than the predetermined number of pulses, the generator recognizes that the current input signal is due to noise from an unrecorded region of the recording medium, and therefore does not generate the sync signal.

Abstract: This method provides new data storage capabilities that are implemented within the industry standard formats of mountable media data recording devices. The new data storage structures are written into regions presently marked on the mountable media as "contents of this region are not of interest" or marked as "no data was recorded within this region". These data storage structures are transparent to present data recording devices and do not disrupt their data processing functions. However, the data storage structures are available to new data recording devices so that new data embedded therein is used to enhance the functionality of the system which utilizes these data storage structures. The types of embedded data may include ECC (error correction codes), tape position information, audit information, security information, mount history, media defect history, authentication notation, generation-identification notation, etc.

Abstract: A data recording system for recording in a CD-ROM or similar recording medium a data file containing data such as compressed audio and video data and an index file containing index data for searching the individual data of the data file. The data stored in the data file are recorded in a CD-ROM in three hierarchical stages, i.e., titles, scenes and shots or chapters, scenes and clips. The index file has a hierarchical format associated with that of the data file in order to manage the data of the data file in consecutive stages.

Abstract: A system for detecting the servo sectors of a rotating magnetic disk solely from read pulses representative of information read on the disk. Each servo sector has a first or intersector gap, an automatic gain control data zone, a second gap, and a track data zone. Sector pulses indicative of the servo sectors are generated when all these gaps and zones are detected. Preferably, for the production of a write enable signal, the sector pulses thus produced are further compared with window pulses obtained by imparting a prescribed delay to the sector pulses. Writing on the disk is enabled when the sector pulses agree in time with the window pulses.

Abstract: A method and apparatus for accurately locating targeted append points in a tape drive. The effects of interlayer slip (ILS) are eliminated and smaller IBGs are possible thus providing increased data capacity for a given tape cartridge. A coarse tachometer count is used in combination with the read dataflow to accurately locate the proper append point even with a small IBG size. The appended data are assured to be written using the proper tape velocity which virtually eliminates improper write appends and read temporary errors previously caused by ILS effects. The solution also guarantees that customer data previously written to the tape are not accidentally overwritten.

Abstract: A method for duplicating data on a rotating magnetic disk in sectors on concentric tracks so that the sectors are aligned with each other from track to track and referenced to an index mark. The index mark is sensed as the disk rotates. The time elapsed between sensed index marks is counted to define the angular displacement of the disk. A magnetic head is moved successively to the tracks on the disk. Data to be duplicated is recorded in sequence, sector by sector, on the respective tracks beginning at different offsets from the index mark such that recording begins with the next sector encountered after the head arrives at the respective tracks.

Abstract: Digital signal processing (DSP) employing a differential mean calculation automatically distinguishes sections of blank tape from program material (such as music or voice) on cassette tapes. Blank tape produces a negligible differential mean value while program material produces substantial differential mean values. Thus, each differential mean is compared to a threshold so that a cassette player can be commanded to fast forward through a blank section of tape. A music envelope detector insures that low amplitude music signals are not detected as blank.

Abstract: A record storage format conversion method and a system which is capable of mitigating a load imposed on the memory by decreasing the number of accesses to the memory for finding out a CKD record of concern upon format conversion of the CKD records into FBA records while allowing the capacity of a memory required for holding the track data to be decreased. All gaps inclusive of inter-record gaps and inter-field gaps are deleted from variable length records of one track recorded in a variable length format employed in an external storage device of a general-purpose computer. The track data thus obtained is divided into management units each of a predetermined size corresponding to an integral multiple of the size of the fixed length block of the fixed length record.

Abstract: Apparatus and method are provided to increase the capacity of spiral track data storage disks while improving the reliability of access to sectors on the disk by permitting previously unusable sectors immediately following a band boundary to be reliably accessed. In accordance with the present invention, an optical drive controller is provided having a clock for generating a clock signal with a frequency of f.sub.N and a cycle slipper for generating a slipped clock signal with a frequency of f.sub.N-1 from the clock signal. The controller also includes a device for enabling the slipper when an optical head is positioned opposite a sector in a band N-1 during a seek operation to a target sector in band N, and for disabling the slipper when the optical head is positioned opposite the end of the last sector in band N-1. Thus, identification information pertaining to sectors in band N-1 is processed at a data transfer rate of f.sub.N-1 and the data transfer rate is switched to f.sub.

Abstract: A method and system for accurately reading and storing data as multiple data blocks on a removable data storage medium mounted within a data storage system. Each data block includes an initial acquisition data character and multiple diverse synchronization characters/bursts and adjacent data blocks are separated by a unique interblock gap character. A multimodal interblock gap character detection circuit is provided which may operate in a normal mode of operation or a stringent mode of operation, wherein an enhanced degree of certainty is required for detection of the interblock gap character. A predicted time window of occurrence for a next interblock gap character is generated in response to detection of an initial acquisition data character and at least one synchronization character within a data block. Additionally, a global clock count signal based upon multiple track outputs is generated each time a resynchronization burst is encountered.

Abstract: An apparatus and method for generating an index pulse by a data storage tape drive. The tape drive is controlled by a flexible disk controller. A multi-track tape is formatted into multiple data segments per track with erased areas between segments. A digital data signal from the tape signal processor is sampled to detect a lapse in data. Then, the analog data signal is continuously monitored to detect the reappearance of data. When filtered analog signal peaks exceed a fixed threshold, a pulse is generated from the tape drive to the flexible disk controller. In an alternative embodiment, to further protect against false triggering, index pulse generation is suppressed during most of each erased area between segments. In another embodiment, index pulse generation is suppressed if an erased area exceeds a length threshold, such as at the end of the tape. In still another embodiment, index pulse generation is suppressed if digital data reappears without triggering the analog monitoring circuit.

Abstract: A method for storing data onto a magnetic tape from one or more sources includes providing a first temporary storage area for temporarily holding data and a second temporary storage area for temporarily holding housekeeping information. The first temporary storage area contains a predetermined number of data holding areas of fixed size. A quantity of data to be stored is read into the first data holding area of the first temporary storage area. Housekeeping information identifying the data held in the first data area and its location therein is formulated and written into the second temporary storage area. The process is repeated until the first storage area is full or there is no more data to store. The contents of the first and second temporary storage areas are then written onto the tape as a single unit. The procedure is repeated as necessary until the tape is full or all of the data to be stored has been written onto the tape.

Abstract: An arrangement for recording an information signal in a track (T.sub.0, T.sub.1, . . . ) on a record carrier (1), includes an input (20) for receiving the information signal, signal processing circuitry (21) for processing the information signal such that it can be recorded in the track, counting device (23) for counting and for generating an array of subsequent different count signals and for supplying the count signals to an output (24), recording apparatus (25, 26, 27) having at least one recording head (26) for recording the processed information signal in a track on the record carrier, and for recording the count signals in a track on the record carrier and a transport apparatus (34,35) for transporting the record carrier with a certain transport velocity (v.sub.t) in a longitudinal direction of the record carrier.

Abstract: A plurality of data sequences having patterns distinguishable from informational data are recorded as a servo mark portion of servo information on a disk. Upon decoding a predetermined number of these data sequences, a determination is made as to whether an accurately located servo mark has been detected. The detected servo mark provides a reference from which the beginning of recorded servo burst data can be located, thereby enabling all of the servo burst data to be read. The presence of defects does not inhibit the detection of the servo mark.

Abstract: A digital recording and reproducing system, in which frames are recorded in a track on a record carrier. The frames alternate with interframe gaps. The interframe gaps as recorded in the track on the record carrier have a variable length.

Abstract: Information bearing signals are recorded in one of a plurality of record formats on one record medium, such as a magnetic tape, magnetic disk, optical disk, and the like. The format selected may be commanded or based upon record lengths, in bytes. When the record length equals or exceeds a predetermined number of bytes, then one record is recorded in each signal block of the record format. When the record length is less than the predetermined number, then a second format is used which inserts several of the records in one of the signal blocks. The signal block and its packets respectively contain indications of formats such that any one of several formats may be used on one record medium and in one signal block having a plurality of variable length packets. Logical indicators, such as format marks, tape marks, and the like, may separate formats used on the storage medium.

Abstract: A dedicated servo disk is encoded with a plurality of bit frames. Each bit frame is positioned between synchronizing bits. Each bit frame contains a first and second portion in timed succession and a plurality of servo bits are arranged in first and second distinct patterns. A bit frame can contain an intermediate code bit with a plurality of intermediate code bits and quadrature position signals used to form the unique track address. The track address is repeated throughout the associated servo track. The dedicated servo disk is used in an servo address system.

Abstract: In a rotating disk drive for storing and retrieving data used by a host system computer, a narrow gap is provided within a data sector format for each concentric data track of the drive. This gap may be normally located at the end of the track, in a speed tolerance buffer region following the last sector. In the event a media defect is detected which otherwise falls within a NAR area for a particular sector, this gap may be shifted to the beginning of the data track, thereby shifting all of the sectors and their NAR areas backward by the width of the gap. The media defect otherwise falling into the NAR area of a particular sector then falls harmlessly into a data field of a preceding sector, and this preceding sector may then be read and mapped out of service by insertion of a spare sector within the physical track without any loss of user data storage capability.

Abstract: A dual mode disk controller is disclosed for use between a host processor and its storage medium for controlling data transfer to and from the storage medium. The data is formatted on the medium in two distinct formats, one capable of bulk fast transfers useful in a swapping operation, and the other capable of periodic slower transfers as is acceptable for file retrieval. The disk controller is designed having a small fast buffer memory for accepting information from the storage medium. File transfer data is transferred immediately without host CPU intervention, to a larger cache memory. The host CPU accesses the fast buffer memory periodically to retrieve swap transfer data while only accessing the larger cache memory when it needs to retrieve the file formatted information.

Abstract: Block pattern detection circuitry for the read subsystem of a streaming tape drive system comprises a state machine, a pattern decoder, a tape mark detector, a block/gap filter, a block/gap meter, a verify count section, and a block read/verify section. The incorporation of a hardware state machine within the block detect circuitry permits the application of historical detect data in the interpretation of present detect data. This provides more certain pattern recognitions. Also, state data is fed back to the block/gap filter allowing precise block boundary triggers which are used by position capture circuitry and the drive controller to effect more precise re-try positioning. The use of the block/gap filter increases the detect circuitry's immunity to noise. The advantage is enhanced where the block/gap filter uses stochastic thresholding, which is also advantageously employed by the tape mark detector.

Abstract: A method of and apparatus for generating and protecting hard sector pulses using the read/write heads of the disk drive without using any external transducers is disclosed. Each track of the disk is pre-formatted with a pattern of a burst of data followed by a short erased gap repeated around the track once per sector. The data bursts are converted to digital pulses which are used to trigger a monostable as long as the read/write heads are positioned over data. The lack of an output signal from the monostable is used to detect the erased gaps. At the end of the erased gap, a sector marker pulse is generated. Various protection signals are also generated. The high capacity hard sectored computer disk drive system disclosed herein utilizes a hard disk which rotates at a speed of approximately 2750 r.p.m. The data received from the host computer for storage on the hard disk is converted to 2,7 RLL coding prior to being written onto the disk.

Abstract: In a helical-scan tape recorder, a digital signal having a series of M identification words of N bits each is generated. One of the N-bit words is a discrimination word identifying a particular combination of the other N-bit words. The M words are organized into J groups of I words each (where J.times.I=M) and recorded with an information signal at spaced intervals within each of a series of sectors defined along each track of a recording tape so that the word groups are interleaved with the information signal and each of the recorded sub-blocks can be traced substantially simultaneously by a transducer head during a search mode. At least one of the word groups includes data bits identifying distinct, but mutually closely related items of information and discrimination bits which identify the data bits. During search mode, distribution bits can be detected with the data bits of the same word group to allow the closely related items of information to be displayed.

Abstract: A digital video signal reproducing apparatus comprises a reproducing circuit for reproducing a digital video signal from a recording medium, where the recording medium is time-sequentially recorded with the digital video signal having a signal format in which a header signal is added to each of divided picture element data groups which are obtained by dividing a picture element data group in terms of a predetermined unit, the picture element data group is obtained by subjecting an analog video signal to a digital pulse modulation at a sampling frequency such that a product of a number of picture element data in one scanning line and an effective number of scanning lines in one picture of a standard television system is exceedingly close to 2.sup.18 but less than 2.sup.

Abstract: Digitally encoded information is stored on a data track in an improved format characterized by a leader field followed by a data field and a trash gap at the end of the data field. On a rotatable disk storage medium, the leader field has a randomly selected starting point which may change each time a new set of data is recorded on the track. The leader field contains encoded control information which signals the beginning of the ensuring data field. The trash gap may contain spurious data remaining from a previously recorded set of data and is maintained shorter than the leader field at all permissible rotational speeds of the disk to prevent spurious data on the trash gap from being erroneously recognized as valid leader field control information.

Abstract: This invention relates to the recording and reproducing of digital data on magnetic tape and, more particularly, to increasing the effective data recording density via reducing the lengths of the interblock gaps. The tape is stopped and started with moderate accelerations, in distances which are generally greater than the interblock gap length. In a particular form of the invention, when the tape is to be stopped at the end of a data block, it is stopped in a distance greater than the gap length, reversed and brought to rest with the record/reproduce head on the interblock gap. When the tape is to be started, it is first reversed for a short distance, and then driven in the desired direction such that it is up to normal operating speed at the end of the interblock gap. The interblock gap length may be substantially shorter than the distance required to stop and start the tape. The effective data recording density is increased through this interblock gap length reduction.

Abstract: A recording system is provided for a picture information file device having a keyboard, a 2-dimension scanning device, a magnetic tape device, a display device, and a microprocessor. When registering new picture information, a retrieval title to which a delete mark is attached is searched. The length of the picture information recorded at the position represented by this retrieval title is compared with the length of the new picture information to be recorded. If the new picture information to be recorded is shorter, the new picture information is recorded in the deleted picture information area. If the new picture information is longer, another retrieval title with a delete mark attached thereto is searched and the same comparison is made.

Abstract: A magnetic tape recorder is removably secured to an electronic digital information processing apparatus of the portable type for storing digital information and audio information. The digital information stored in the magnetic tape recorder is let out from the magnetic tape recorder in response to commands introduced through a keyboard means included in the electronic digital information processing apparatus and is displayed on a digital display secured on the electronic digital information processing apparatus. In a preferred form, another keyboard means is removably associated with the electronic digital information processing apparatus, whereby many kinds of information can be stored in the magnetic tape recorder.

Abstract: Method and apparatus for dividing a track on a magnetizable information storage disc into sectors by writing sector identification information into the track. In order to optimize the storage capacity of a track on a magnetizable information storage disc the track is first filled with information bytes in response to the occurrence of the leading edge of an index pulse (a) derived from the disc in such manner that a predetermined number of bytes fill a portion (ix) of the track, followed alternately by sector identification bytes and further bytes defining the data field of the relevant sector in portions SK and DT respectively until the final group of sector identification bytes has been written into portion SKn, followed by further bytes into portion z until the leading edge of the next index pulse occurs.

Abstract: A positioning system for a magnetic tape system that utilizes a multiple record recording format wherein positioning data that marks the beginning of record segments, the beginning of the tape medium, and the ending of the tape medium are pre-recorded at one-fourth of the bit density of work data so that positioning data may be more accurately read at a higher tape speed during a record seek mode of operation. The system also includes detector circuitry that is enabled only upon detecting positioning data and that identifies the positioning data as an inter-record mark signal, beginning of tape signal, or an ending of tape signal. A tape drive controller is responsive to the detection circuitry for controlling the speed and direction of the magnetic tape.

Abstract: A data-recording device wherein a plurality of tracks are concentrically provided on the recording surface of a rotatable magnetic recording medium. A plurality of sector-starting positions are arranged on the respective tracks at a given circumferential interval to detect the extent to which the magnetic recording medium has been rotated, and one sector-starting position among the sector-starting positions of the respective tracks is used as a point at which the writing or reading of data is to be commenced.

Abstract: A control unit for supervising operation of data transmission to and from a data storage device such as a disk storage device, has a stored program for the unit, and a random access memory sufficient to store an entire block of data received from the data storage device. In one arrangement, the control unit works in conjunction with external data processing apparatus, and the control unit controls interchange of data between the data processing apparatus and the data storage device. The external data processing apparatus has a reduced memory capacity requirement, because of the control unit, and delays caused by static timing requirements are minimized. When the data storage device is a disk storage device, reading is performed without delay, using the first available sector of the disk in a given track.

Abstract: Apparatus and method for controlling a reel-to-reel tape drive so that its performance characteristics are optimized to best suit the operational mode or availability of a host system by modifying tape speed adaptively according to predetermined conditions sensed during processing of data (i.e., while the tape is in motion). For example, tape might initially be fed at a high speed suitable for archiving; but if more than a predetermined number of "backhitches" (overruns of the interblock gap, IBG) occur during processing of a preselected number of successive blocks of data, the host will cause tape speed automatically to be reduced to a lower rate. This lower rate will enable the tape to stop in the IBG and is therefore suitable for intermittent processing.Preferably, before reducing speed during write operations, appropriate signals are generated at the host to command an increase in the IBG from a normal distance to a larger distance if backhitches exceed said preselected number.

Abstract: High tape acceleration rates are achieved in an unbuffered, capstanless tape drive system by a tape motion control apparatus employing separate drive motors for each reel of a reel-to-reel tape transport. Tape moves from one reel past a read/write head and a tape tension sensor to the other reel, there being no tachometer in the tape feed path. A tachometer on one reel shaft provides a large number of pulses per revolution which pulses are counted by a counter; and a tachometer on the other reel shaft provides only one pulse per revolution, which pulse gates out the count then accumulated in the counter for actuating means to provide motor acceleration currents of a magnitude corresponding to said accumulated count according to a predetermined servo algorithm for controlling rotation of both reels. A tape radius constant corresponding to the actual length and thickness of tape in the system is calculated during initial wrap of tape onto the takeup reel.

Abstract: Each data record portion on a record member includes preamble signals for synchronizing recording apparatus with respect to data signals recorded in juxtaposition to the preamble signals. A plurality of beginning of data indicators are interleaved in the synchronizing signals for providing a plurality of independent but coacting beginning of data location pointers. Enhanced apparatus includes means responsive to any one of the location pointers to ensure a reliable start of data indication.

Abstract: Apparatus and a method for controlling the reading and writing operation of a peripheral storage system such that a magnetic recording medium, having small defective areas in the magnetic surface at which data cannot be reliably recorded may be used. Each data track on the magnetic recording medium has a reserve capacity which is used as a special gap. The recording medium is initialized such that the distance from a point of origin to a surface defect in each track is recorded in a header area in each track. The apparatus and method herein described cooperate with this initialized magnetic recording medium so as to control the format of data recorded onto the magnetic recording medium such that any defect in the recording medium will not affect a reading or writing operation of the storage system.

Abstract: A system wherein a magnetic tape is divided into a plurality of data storage blocks, each of which is preceded by a unique block marker. A phase encoder and phase decoder associated with the read/write head are connected by a data control circuit to a computer. As the head scans the block marker, the phase decoder supplies the computer with the block marker data via the data control circuit. Immediately after a predetermined block marker has been read, the computer provides the data control circuit with a write-signal and makes available a byte of parallel data to be written on the tape. The data control circuit includes an erase latch activated by the ongoing transition of the write-signal for providing the phase encoder with an erase-signal which causes the first byte on the magnetic tape following the block marker to be an erased gap.