Abstract:
A data storage apparatus in which an interface for a pre-existing floppy disc and another interface for a large-capacity floppy disc compatible with the pre-existing floppy disc are provided and can be operated effectively independently of each other. A disc sort discriminating circuit discriminates the type of the disc loaded on the apparatus to send the results of discrimination to a controller. The controller is responsive to the results of discrimination to control a FDD interface which is an interface for the pre-existing floppy disc and an IDE interface which is an interface for the large-capacity floppy disc. The interface pertinent to the type of the loaded disc is controlled to perform a recording/reproducing operation corresponding to the accessing, while the interface pertinent to the type of the non-loaded disc is controlled to return a disc-absent response to a host computer.

Description:
BACKGROUND OF THE INVENTION  
         [0001]    1. Field of the Invention  
           [0002]    This invention relates to a data storage apparatus and, more particularly, it relates to a data storage apparatus on which can be loaded or unloaded plural sorts of recording mediums.  
           [0003]    2. Description of Related Art  
           [0004]    A data storage device used as a peripheral for a compute, such as a floppy disc drive device, usually has a sole interface with a host computer.  
           [0005]    For example, a floppy disc drive device for driving a conventional 3.5-inch floppy disc having a recording capacity of 1 or 2 megabyte, has a so-called floppy disc drive (FDD) and has communication over this FDD interface with a host computer. Within the host computer is enclosed a floppy disc controller (FDC) for controlling the floppy disc drive device via FDD interface. This FDD interface lends itself to cost reduction in suppressing the data transfer speed and in limiting the control function. By storing a system file in a conventional 3.5-inch floppy disc and by loading the 3.5-inch floppy disc having the system file stored therein in advance at the time of starting of the host computer, the host computer can be started on the basis of the system file stored in the 3.5-inch floppy disc.  
           [0006]    To the host computer is connected, besides the floppy disc drive device, a CD-ROM driving device, for example, via an interface other than and more intelligent than the FDD interface, such as IDE (intelligent drive electronics) interface. However, the host computer is configured not to be started by an equipment connected thereto by an interface other than the FDD interface.  
           [0007]    Meanwhile, there is a demand for a large-capacity floppy disc drive device larger in recording capacity and higher in transfer rate than the conventional 3.5-inch floppy disc. Moreover, since the 3.5-inch floppy disc is used worldwide, the driving device for the large-capacity floppy disc desirably can be used not only for a conventional large-capacity floppy disc but also for the 3.5-inch floppy disc. Moreover, the host computer desirably can be started on the basis of a system file having the conventional FDD interface and which is recorded on the conventional 3.5-inch floppy disc. For the large capacity floppy disc, an interface other than the FDD interface which is an intelligent high transfer rate FDD interface, is desirably employed.  
         SUMMARY OF THE INVENTION  
         [0008]    It is an object of the present invention to provide a data storage device capable of having communication with a host computer impeccably even if it has plural interfaces.  
           [0009]    The present invention provides a data storage apparatus on which is detachably loaded one of plural types of the recording mediums, including a plurality of interfaces provided in association with different types of the recording mediums for connection to an external control device, means for discriminating the type of a loaded recording medium and control means which, when a command is supplied via one of the interfaces from the external control device, discriminates whether or not the interface coincides with the type of the loaded recording medium. The control means performs an operation corresponding to the command if the interface coincides with the type of the loaded recording medium. The control means sends the information specifying the absence of the loaded recording medium via the interface to the external control device.  
           [0010]    FDD or IDE interface is among said plural interfaces.  
           [0011]    According to the present invention, plural types of interfaces each associated with plural types of the recording mediums are provided and the type of the loaded recording medium is discriminated to control the operation of the associated interface to switch automatically the operation or response of the interfaces responsive to the loaded recording medium to permit appropriate processing responsive to the accessing from the host computer.  
           [0012]    Also, if the interface associated with the loaded recording medium is allowed to perform the usual operation, while the interface not associated with the loaded recording medium is allowed to make a response which the interface makes in the absence of the recording medium, the host computer can perform the operation similar to that if the data storage apparatus is connected to the associated with the interface. In particular, if an accessing request is sent from the host computer to the recording medium of the type different from the type of the loaded recording medium, a response to the effect that there is no loaded recording medium is returned to the host computer, so that a sole data storage apparatus can be used as plural apparatus without imposing any large load on the user.  
       
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0013]    [0013]FIG. 1 is a block diagram showing an example of a disc drive device embodying the present invention.  
         [0014]    [0014]FIG. 2 shows an example of a large-capacity floppy disc and a pre-existing floppy disc.  
         [0015]    [0015]FIG. 3 shows another example of a large-capacity floppy disc.  
         [0016]    [0016]FIG. 4 is a block diagram showing an example of a computer-side structure.  
         [0017]    [0017]FIG. 5 is a flowchart for illustrating the operation of confirming the possible presence of a disc and of discriminating the disc type.  
         [0018]    [0018]FIG. 6 is a flowchart for illustrating bootstrap processing at the time of system startup of the computer.  
         [0019]    [0019]FIG. 7 is a flowchart for illustrating the operation on accessing request to a large-capacity floppy disc.  
         [0020]    [0020]FIG. 8 is a flowchart for illustrating accessing request to a pr-existing floppy disc.  
     
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS  
       [0021]    Referring to the drawings, preferred embodiments of a data storage device according to the present invention will be explained in detail.  
         [0022]    [0022]FIG. 1 shows an example of a disc drive device  10  embodying the present invention. It is assumed that at least two sorts of the floppy discs  1 A and  1 B, as shown in FIGS. 2A and 2B, are usable in the disc drive device  10  shown in FIG. 1. Specifically, FIG. 2A shows a conventional floppy disc  1 A holding a disc  2 A of a high recording density mode (upper order mode) having a large recording capacity, while FIG. 2B shows a floppy disc  1 B of a standard recording density (lower order mode) having the recording capacity on the order of, for example, 2 Mbyte. In FIGS. 2A and 2B, write protectors  5 A,  5 B denote a writing enabling state and a writing inhibiting state when holes are closed or opened, respectively. Specifically, a hole  6  in FIG. 2B denotes a pre-existing floppy disc  1 B. Also, in FIG. 2A, a hole  7  provided at a predetermined position other than the write protector  5 A or the hole  6  in FIG. 2B indicates the upper order mode floppy disc  1 A for high density recording.  
         [0023]    For identifying the upper order mode high capacity floppy disc, a light reflecting member  8  shown in FIG. 3 may be provided, or possible presence of a cut-out or difference in reflectance may be used as identification means. If plural sorts of the upper order mode are prescribed due to difference in the recording capacity, plural sorts of the upper order mode may be discriminated based on the combination of presence and absence of plural holes.  
         [0024]    Reverting to FIG. 1, there are built into a magnetic head  11  for recording/reproducing data on or from floppy discs  1 A or  1 B a head chip  2  for the low order mode floppy disc  1 B and a head chip  13  for the upper order mode floppy disc  1 A. A motor  14  runs the floppy discs  1 A,  1 B in rotation. A controller  15  controls the operation of the entire disc drive, such as movement control of the magnetic head  11 , and is responsive to mode signals (signal representing the upper order mode or the lower order mode) to change over the rpm of the motor  14 , recording/reproducing circuit or the interface. A detection signal from a sensor  16 , adapted for mechanically or optically detecting the sorts of the floppy disc  1 A or  1 B is sent via a disc sort discriminating circuit  17  as the aforementioned mode signal to the controller  15 . It can be discerned whether the floppy disc  1 A or the floppy disc  1 B has been loaded based in position on whether or not the mode signal is sent to the controller  15 .  
         [0025]    The recording/reproducing system, connected to the head chip  12  for the lower order mode, includes an amplification circuit  21 , a modulation/demodulation circuit  22 , a formatting/deformatting circuit  23 , an error processing circuit  24 , a buffer memory  25  and an FDD interface  26 . The recording/reproducing system, connected to the head chip  13  for the upper mode, is made up of an amplification circuit  31 , a modulation/demodulation circuit  32 , a formatting/deformatting circuit  33 , an error processing circuit  34 , a buffer memory  35  and an IDE interface  36 .  
         [0026]    Referring to FIG. 4, an illustrative structure of a computer system, to which is connected the disc drive device  10  according to the present invention, is explained.  
         [0027]    Referring to FIG. 4, a host computer  100  includes a CPU  70 , a ROM  82 , a RAM  74 , an FDC  75 , an FDD interface  76 , an IDE interface  77 , a SCSI interface  78 , an IDE interface  83  and an HDD  85  having an IDE interface  84 , these being interconnected over a bus  71 . In the ROM  82  are included a basic input/output system (BIOS)  79  and a bootstrap loader  73 .  
         [0028]    To the SCSI interface  78 , FDD interface  76  and to the IDE interface  77 , there are connected an SCSI interface  81  of a SCSI device  80 , a FDD interface  10  of the disc drive device  10  and an IDE interface  36  of the disc drive device  10 , respectively.  
         [0029]    In the system shown in FIG. 4, the CPU  70  operates at the time of system startup such as power up or resetting of the host computer  10 , in order to check the possible connection of an external storage device. The CPU  70  then operates on the basis of a bootstrap loader  73  in a startup ROM  72  to load the system file from the floppy disc or the hard disc.  
         [0030]    The operation of the CPU  70  at the system start is explained.  
         [0031]    During startup of the host computer, the CPU  70  operates on the basis of, for example, BIOS  79  of FIG. 4, in order to perform reliability tests or initialization. The control right of the CPU  70  is then transferred to the bootstrap loader  73  stored in the startup ROM  72 . The CPU  70  then is operated on the basis of the bootstrap loader  73  to perform bootstrap processing shown in FIG. 5.  
         [0032]    The CPU  70  first discriminates at step S 91  whether or not the FDD  10  is connected in circuit. If the result is YES, processing transfers to step S 92  and, if otherwise, to step S 96 . At step S 92 , the CPU  70  discriminates, based on the possible supply of the mode signal from the disc sort discriminating circuit  17 , whether or not the floppy disc  1 A or  1 B has been loaded in position. That is, if the mode signal has been supplied via controller  15 , FDD interfaces  26 ,  76  and the CPU bus  71 , the CPU  70  decides that the floppy disc  1 A or  1 B has been loaded in position, and proceeds to step S 93 . If there is supplied no mode signal, the CPU  70  decides that the floppy disc  1 A or  1 B has been loaded in position, and proceeds to step S 96 .  
         [0033]    At step S 93 , the CPU  70  decides whether or not bootstrapping is possible based on the information stored in the floppy disc  1 A or  1 B loaded on the FDD  10 . That is, if it is the conventional floppy disc  1 B that is loaded on the FDD  10 , and the system file is recorded on the floppy disc  1 B, the CPU  70  decides that bootstrapping is possible. The CPU  70  judges that the system file has been recorded on the floppy disc  1 B by controlling the magnetic head  11  via FDC  75 , FDD interfaces  76 ,  26  and the controller  15  to read out the information from a predetermined recoding position of the floppy disc  1 B to retrieve the information once stored in the buffer  25  via FDD interface  26  and so forth.  
         [0034]    If the system file has been recorded in the floppy disc  1 B, the CPU  70  proceeds to step S 94  to send a command of reading out the system file from the floppy disc  1 B via the FDD interface  76  to the FDD  10 . This sends the system file read out from the floppy disc  1 B to the host computer  100  via FDD interface  76  so as to be retrieved by the RAM  74 . The CPU  70  then shifts from the operation which is based on the bootstrap loader  73  to the operation which is based on the system file retrieved into the RAM  74 .  
         [0035]    If the system file has not been recorded in the floppy disc  1 B, the CPU  70  proceeds to step S 95  to indicate on a monitor, not shown, that the system disc is not in operation.  
         [0036]    If the CPU  70  judges at step S 91  that the FDD  10  is not connected in circuit, or if the CPU decides at step S 92  that the floppy disc  1 A or  1   b  is not loaded in position on the FDD  10 , the CPU proceeds to step S 96  in order to judge whether or not the HDD  85  is connected in circuit. If the HDD  85  is connected in circuit, the CPU proceeds to step S 97  and, if otherwise, to step S 100 . In the latter case, the system has not been started up.  
         [0037]    Also, when the CPU  70  proceeds to step S 97 , it decides whether or not bootstrapping is possible. Specifically, the CPU judges whether or not the system file has been recorded on the hard disc, not shown, of the HDD  85 . If the system file has been recorded, the CPU  70  proceeds to step S 98  to retrieve the system file from the hard disc tot the RAM  74 . The CPU  70  then operates based on the system file. If at step S 97  there is recorded no system file on the hard disc such that bootstrapping is not possible, the CPU  70  proceeds to step S 99  to display the effect that there is no system file on a monitor, not shown.  
         [0038]    As the interface for a high recording density (upper order mode) disc of the disc drive device of FIG. 1, an extended IDE interface (EIDE interface), SCSI or IEEE (institute of Electrical and Electronics Engineers) 1394 standard interface, may be used in place of the above-mentioned IDE interface.  
         [0039]    If, in the disc drive device  10  having compatibility between the upper order mode floppy disc  1 A and the lower order mode floppy disc  1 B, recording/reproduction is to be performed on or from the floppy disc  1 B of the lower order mode, an accessing request is made for recording/reproduction from the external host computer  100  to the FDDIF  28 , and the possible presence of the floppy disc  1 B of the lower order mode is discriminated by the sequence of operations which is to be explained subsequently. If it is found that there is the disc, data is recorded from the host computer  100  or data is reproduced from the floppy disc  1 B.  
         [0040]    Specifically, during recording, recording data are stored via FDDIF  26  in the buffer memory  25  and thence sent to the error processing circuit  24  for generation and appendage of e.g., CRC. The resulting data is sent to the formatting/deformatting circuit  23  for conversion to data of a format having a sector structure suited to the recording on the pre-existing floppy disc  1 B. The formatted data is sent to the modulation/demodulation circuit  22  for digital modulation, such as modified frequency modulation (MFM), and is amplified by the amplification circuit  21 , from which it is routed to the head chip  12  for the lower order mode for recording on the floppy disc  1 B.  
         [0041]    During reproduction, the operation is the reverse of that during recording. That is, data reproduced by the had chip  12  from the floppy disc  1 B is amplified by the amplification circuit  21  and processed with digital demodulation by the modulation/demodulation circuit  22 . It is further deformatted by the formatting/deformatting circuit  23  and checked for errors in the error processing circuit  24 . The resulting data is sent via buffer memory  25  and FDDIF  26  to the host computer  100 .  
         [0042]    For recording/reproduction on or from the upper order mode floppy disc  1 A, an accessing request for recording/reproduction is made from the external host computer  100  to the IDEIF  36 . The possible presence of the floppy disc  1 A of the upper order mode is discriminated by the sequence of operations as later explained. If the floppy disc  1 A of the upper order mode is found to be present, data is recorded on the floppy disc  1 A or data recorded on the floppy disc  1 A is reproduced.  
         [0043]    Specifically, during recording, the data is stored via IDEIF  36  in the buffer memory  35 , from which data is sent to the error processing circuit  34  for generation and appendage of the parity or error correction codes. Output data of the error processing circuit  34  is sent to the formatting/deformatting circuit  33  for conversion to data of the format having the sector structure suited to recording on the upper order mode floppy disc  1 A. The formatted data is sent to the modulation/demodulation circuit  32  for digital modulation, such as MFM. The modulated data is amplified by the amplification circuit  31  and sent to the head chip  13  for the upper order mode for recording on the floppy disc  1 A.  
         [0044]    During reproduction, the operation is the reverse of that during recording. That is, data reproduced by the head chip  13  from the floppy disc  1 A is amplified by the amplification circuit  31  and processed with digital demodulation by the modulation/demodulation circuit  32 . It is further deformatted by the formatting/deformatting circuit  33  and checked for errors in the error processing circuit  34 . The resulting data is sent via buffer memory  35  and FDDIF  36  to the host computer  100 .  
         [0045]    If the floppy disc  1 A or  1 B is inserted into the disc drive device of FIG. 1, the possible presence of the hole  7  in FIG. 2 is detected by the detector  16 . The dis type is discriminated, that is, it is discriminated whether the disc inserted is the upper order mode floppy disc  1 A or the lower order mode floppy disc  1 B. The results of detection are sent as a mode signal to the controller  15 . Based on this mode signal, the controller  15  selects one of the IDEIF  36  or FDDIF  26 . On the other hand, the host computer  100  can make accessing requests to an optional one of plural interfaces provided in the disc drive device  10 . Thus, it may be an occurrence that an accessing request be made from the side of the host computer  100  to the disc drive device  10  without the user not being aware which of the floppy discs  1 A and  1 B has been loaded on the disc drive device. In this case, it is up to the disc drive device  10  to make some response to the request from the host computer  100  by whichever one of the interfaces of the disc drive device  10 . Specifically, the interface which is accessible on insertion of the floppy disc  1 A or  1 B performs data recording/reproduction and a response is made to a request for other invalid interfaces to the effect that there is no corresponding floppy disc.  
         [0046]    The operational sequence in the controller  15  for doing this control is explained with reference to FIGS.  6  to  8 .  
         [0047]    [0047]FIG. 6 is a flowchart for illustrating the operation of checking the possible presence of the disc and as to the disc type. It is noted that the controller  15  performs the operation of FIG. 6 at stated time intervals. In FIG. 6, the controller  15  checks at step S 41  whether or not the floppy disc  1 A or  1 B has been inserted. If the result is YES, the controller  15  proceeds to step S 42  and, if otherwise, it proceeds to step S 45 . Specifically, if the mode signal is supplied from the disc sort discriminating circuit  17 , the controller  15  judges that the floppy disc  1 A or  1 B has been inserted.  
         [0048]    If the controller  15  has proceeded to step S 45 , it sets the flags A and B to 0. If the controller  15  has proceeded to step S 42 , it decides whether the upper order mode floppy disc  1 A or  1 B has been inserted. If the disc is the upper order mode floppy disc  1 A, the controller  15  proceeds to step S 43  to set the flags A and B to 1 and 0, respectively. If the disc is the lower order mode floppy disc  1 B, the controller  15  proceeds to step S 44  to set the flags A and B to 0 and 1, respectively.  
         [0049]    [0049]FIG. 7 is a flowchart for illustrating the operation of the controller  15  when an accessing request has been made from the host computer  10  to the IDEIF  36  which is the above-mentioned upper order mode interface. Specifically, the flowchart shows the operation of the controller  15  when a command specifying an accessing request from the host computer  100  is sent via the FDDIF  26  to the controller  15 . If an accessing request has been made to the upper order mode floppy disc  1 A, the controller  15  checks at step S 51  whether or not the flag A specifying the presence of the upper order mode floppy disc  1 A is 1. If the result is YES, the controller proceeds to step S 62  to perform a recording/reproducing operation in meeting with the accessing request to the disc  1 A. That is, the controller  15  controls the motor  14  and the head chip  12  for the lower order mode in order to perform recording/reproduction in meeting with the accessing request. If the result of at step S 51  is NO, the controller  15  proceeds to step S 63  to advise the IDEIF  36  of the absence of the medium (floppy disc  1 A) to make a response to the host computer  100 . The response in this case includes displaying a message which reads: “There is no disc” or “there is no disc readied” on the host computer  100 .  
         [0050]    [0050]FIG. 8 is a flowchart or illustrating the operation of the controller  15  when an accessing request is made from the host computer  100  to the FDDIF  26  which is the lower order mode interface. At this time, the controller  15  checks at step S 61  whether or not the flag B specifying the presence of the floppy disc  1 B of the lower order mode is 1. If the result is YES, the controller  15  proceeds to step S 62  to perform a recording/reproducing operation corresponding to the accessing request for the disc  1 B. If the result at step S 61  is NO, the controller  15  proceeds to step S 63  to advise the FDDIF  26  that there is no medium (floppy disc) to make a response to the host computer  100 . As typical of the response in this case, a message to the effect that there is no disc or a message to the effect that there is no disc readied on a monitor of the host computer.  
         [0051]    In the above-described embodiment of the present invention, the FDDIF  26 , as an interface such as a pre-existing 3.5-inch micro floppy disc and an IDEIF  36  as an interface convenient for a floppy disc of the recording capacity of the order of tens to hundreds of megabytes, can be used on the same floppy disc device  10 . By the controller  15  monitoring the possible presence or types of the floppy discs  1 A and  1 B and monistically controlling accommodation to a pertinent interface, it is possible for the host computer  100  to recognize the respective interfaces as interfaces of different drives to return a response that there is a disc present only for the interface pertinent to the inserted floppy disc  1 A or  1 B or a response that there is no disc present for any other interface. The result is that connection is made to the disc drive device  10  supporting plural formats without changing the control system from the host computer  100 . Since the disc type is discriminated automatically, any operation other than the operation of inserting the floppy disc  1 A or  1 B is unnecessary to simplify the operation. Also, since a response to the effect that there is no disc is made even if the requested type of the floppy disc  1 A or  1   b  is not inserted responsive to the request from the host computer  100 , mistaken recognition occurs only on rare occasions to assure a user-friendly configuration.  
         [0052]    The present invention is not limited to the above-described configuration. For example, it may be applied to other data storage devices, such as a data storage device handling a floppy disc other than the 3.5-inch floppy disc.