JP3013355U - Floppy disk device - Google Patents

Abstract

(57) [Summary] [PROBLEMS] To provide a floppy disk device capable of switching the rotation speed of an external FDD that can rotate at both 360 rpm and 300 rpm according to a command from a host device. [Structure] A switching signal for the number of rotations of an external three-mode FDD4 is generated using a step pulse generation circuit and sent to the FDD4 through the same signal line as the step pulse. To distinguish the normal step pulse from the rotation speed switching signal, generate more pulses than the normal maximum step pulse number,
This is detected separately on the FDD 4 side and used as rotation speed switching information. Since the rotation speed switching signal is transmitted on the same line as the normal step pulse, the conventional interface can be used as it is.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a floppy disk device (FDD).

[0002]

[Prior art]

 Generally, there are two types of 3.5-inch floppy disks currently used in the market, a double-sided double-density disk (2DD) and a double-sided high-density disk (2HD). There are the following disks, which are roughly classified by formatting them so as to have various storage capacities by a word processor or a personal computer. (1) A disk with a capacity of 640 kilobytes at the time of formatting, which is obtained by formatting a 2DD disk. (2) A disk having a capacity of 720 kilobytes at the time of formatting, which is obtained by formatting a 2DD disc (hereinafter, a 640 kilobyte disc and a 720 kilobyte disc are collectively referred to as a 2DD disc). (3) A disk with a capacity at the time of formatting of 1.25 megabytes obtained by formatting a 2HD disk (hereinafter referred to as a 1.25MB disk). (4) A disc having a format capacity of 1.44 megabytes (hereinafter referred to as a 1.4MB disc) obtained by formatting a 2HD disc. 2 HD discs are widely used in Japan for personal computers, etc. 1. The 25 MB disc is the mainstream. On the other hand, 1.44MB discs are the mainstream for personal computers and other devices that are widely used overseas.

[0003]

[Problems to be solved by the device]

 In recent years, personal computers for overseas have started to spread in Japan. For 2DD discs, both domestic and overseas personal computers can be read and written by using the 720 kilobyte format, and data compatibility can be maintained. However, in the conventional FDD that uses a 2HD disk, many models can read and write only with a capacity of either 1.25 MB or 1.44 MB. The 2DD type and the 2HD type can be distinguished by the opening provided in the disc container, but the difference between the 2HD 1.44MB disc and the 1.25MB disc is that they both use the same 2HD floppy disc. Therefore, it cannot be detected by the disc type determination sensor. For this reason, the conventional external 3-mode FDD is equipped with a manual mode changeover switch. For 2D D type and 2HD 1.25MB type, the disk rotation is manually set to 360 rpm mode and 2HD 1. For the 44MB type, it was manually set to 300 rpm mode. Therefore, the FDD operation is troublesome. The host device side also needs 2DD, 2HD 1.25MB, and 2HD 1.44MB information. This information is the media ID data for disc identification written in the track zero of the disc during formatting. Alternatively, it can be obtained by reproducing information according to this. Also, for the 3.5-inch FDD built in the host device, the interface allows the host device to send the result of discrimination between the 1.25 MB type and the 1.44 MB type by a dedicated signal line. Although the disk rotation speed is automatically switched, the interface is not configured to send the disc determination result to the external FDD to the host device. As described above, the interface of the standard external floppy disk provided in the conventional host device is used for finely discriminating the type of medium or the format state of the medium. No signal line is provided. For this reason, as a result, a mode switching means by manual operation means is provided on the external FDD device side, or a mode other than the floppy disk interface signal line is separately switched. It becomes necessary to connect the signal line. However, in the former case, the operability becomes worse. In the latter case, the entire device becomes expensive, the required space becomes large, and the "system resource" for expanding the function, which is called the "expansion slot" of the host device, is wasted.

Therefore, an object of the present invention is to provide an information processing apparatus capable of automatically setting a mode suitable for a recording medium disc to be used.

[0005]

[Means for Solving the Problems]

 In order to achieve the above object, the present invention provides a disk rotation motor for rotating a plurality of types of floppy disks, and a disk rotation motor having a rotation speed switching signal input terminal. A motor drive circuit that is connected and that rotates the disk rotation motor to a plurality of rotation speeds in response to a rotation speed switching signal input to the rotation speed switching signal input terminal; and a floppy disk. To move the signal conversion head in the radial direction of the disk by including a signal conversion head for performing signal conversion by relative scanning movement of the disk, a read circuit connected to the signal conversion head, and a stepping motor. Head moving device, a step pulse input terminal for driving the stepping motor, the step pulse input terminal and the rotation speed switching signal input terminal. Connected to the maximum number of tracks of the plurality of types of floppy disks, but larger than the number of step pulses required to move the signal conversion head so that it can traverse all tracks. The rotation speed switching signal is formed by detecting that a rotation speed switching step pulse train consisting of a predetermined number of step pulses is inputted to the step pulse input terminal, and the rotation speed switching signal is driven by the motor. The present invention relates to a floppy disk device having a rotation mode determination circuit applied to the rotation speed switching input terminal of the circuit.

[0006]

[Operation and effect of the device]

 In the present invention, it becomes unnecessary to send a signal indicating the number of rotations suitable for the floppy disk used from the host device to the floppy disk device by a dedicated signal line. That is, since the means for sending the stepping pulse for moving the head is also used, and the rotation speed switching information is sent according to the number of step pulses that does not occur in normal head movement, the rotation speed switching information can be extremely easily transmitted. It can be sent and can be detected extremely easily. As described above, by providing the rotation mode determination circuit for determining the rotation speed switching information from the host device, it becomes unnecessary to manually perform the rotation mode switching on the floppy disk device side. Automation of rotation mode switching has been achieved, improving operability.

[0007]

First Embodiment Next, a computer system including a floppy disk device according to an embodiment of the present invention will be described with reference to FIGS.

FIG. 1 schematically shows the whole computer system. This computer system comprises a host device 1, a keyboard 2 as an input device, a display device 3, and an external FDD (floppy disk device) 4 as an information storage device (external storage device). The FDD 4 is connected to the host device 1 by the interface cable 5. The host device 1 has a built-in 3.5-inch FDD 6, and here an MS-DOS (operation system (OS)) made for NEC PC personal computer PC-9801 series is used. The operating system of Microsoft Corporation) and the floppy disk 7 in which the software for executing the mode switching is written are inserted.

FIG. 2 shows the inside of the host device 1 in principle, and has a CPU 8, a ROM 9, a RAM 10, a built-in FDD 6, a mode discrimination signal generating means 6a, and an FDC 11 for FDD.

The external FDD 4 is a 2DD type, 2HD 1.25MB type and 2HD 1. It is configured as a three-mode type that can use three 3.5-inch floppy disks of the 44 MB type. FIG. 3 shows the three-mode FDD 4 in principle, and has a turntable 22, a motor 23, and a motor control and drive circuit 24 as a rotating device for the floppy disk 21. The motor control and drive circuit 24 has a built-in rotation speed switching means and is configured to rotate the disk 21 in two steps of 360 rpm and 300 rpm. Further, the disk 21 is mounted on the turntable 22. When the disk is replaced, that is, when the disk is replaced, the disk is first rotated at 360 rpm. When the disk 21 is, for example, a 2 HD 1.25 MB type, it has 77 tracks concentrically from the outermost track zero T00 to the innermost track Tn. Regardless of the type of the disk 21, well-known media ID data is written in the track zero T00 after formatting.

A head moving device 26 is coupled to the signal converting magnetic head 25 for reading and writing data. The head moving device 26 comprises a stepping motor 27 and a lead screw mechanism 28 for converting this rotational movement into a linear movement of the head 25, and positions the head 25 on a desired track. A well-known control and drive circuit 29 for controlling and driving the stepping motor 27 is connected to the stepping motor 27.

The FDD 4 further includes a well-known read circuit 30, write circuit 31, track zero sensor 32, track zero detection circuit 33, VFO 34, write data input terminal 35, read pulse output terminal 36a, window signal output terminal 36b, and In addition to having a drive select signal input terminal 37, a track zero signal output terminal 38, a step pulse input terminal 39, and a step direction signal input terminal 40, a rotation mode determination circuit 42 as rotation speed switching detection means related to the present invention. Have. The FDD 4 has more input / output terminals (ports), interface circuits, sensors, control circuits, etc., but they are not shown because they are not directly related to the present invention.

The write circuit 31 is connected between the write data input terminal 35 and the head 25. The write circuit 31 is configured to switch the write current according to the change in the type of the disk 21. The read circuit 30 connected to the head 25 waveform-shapes the reproduction signal to form a read pulse including data and a clock. The read circuit 30 includes a well-known waveform filter, and the constant of this filter is switched by the position of the head 25 in the radial direction of the disk 21 and also by the change of the type of the disk 21. Switching of the write current and the filter constant depending on the type of the disk 21 is executed based on a well-known HD sensor (not shown) provided in the FDD 4. The setting of the write current and the filter constant of the 1.25 MB type of 2HD and the 1.44 MB type of 2HD are the same. A known VFO 34 connected between the read circuit 30 and the read pulse output terminal 36a and the window signal output terminal 36b outputs a window signal for separating the data pulse based on the read pulse obtained from the read circuit 30. When it occurs, the read data pulse is extracted at the same time. The track zero sensor 32 is composed of a combination of a photo interrupter and a photo coupler provided in a moving portion of the head moving device 26 in the radial direction of the disk, and an output indicating when the photo interrupter is positioned so as to correspond to the position of the track zero T00. Generate force. Since the accuracy of the output of the sensor 32 is not so high, this output is input to the track zero detection circuit 33, and the track zero is accurately detected by the well-known logic. In this example, the stepping motor control and drive circuit 29 supplies a signal indicating a predetermined excitation phase of the stepping motor to the track zero detection circuit 33. The predetermined excitation phase is a phase excited when the head 25 is phased to track zero. The output of the track zero detection circuit 33 is connected to the track zero signal output terminal 38. The drive select signal input terminal 37 is connected to the read circuit 30 and the write circuit 31.

The mode determination circuit 42 is connected between the step pulse input terminal 39 and the disc rotation motor control / drive circuit 24, extracts the mode determination step pulse, and outputs a motor rotation speed switching signal. Details of the mode determination circuit 42 will be described later.

FIG. 4 is an equivalent view showing a disc discriminating function in the host device 1, a stepping motor control function, and a function for designating a mode based on disc discrimination. The read data creating means 51 is connected to the read pulse output terminal 36a and the window signal output terminal 36b of the FDD 4 and creates parallel read data corresponding to serial read data pulses. The disc discriminating means 52 discriminates the disc type based on the data obtained by the demodulation operation in the data generating means 51. This determination method is as follows, for example. (1) The disk 21 mounted on the turntable 22 is rotated at an initial setting of 360 rpm, the head 25 is positioned at the track zero T00, and the media ID data written therein is read. (2) When the media ID data can be read, the read data is directly used as media information on the host side. (3) If the media ID could not be read in step (1) above, it is determined that the disc is a 2HD 1.44MB type disc other than the 2DD or 2HD 1.25MB type, and a mode switching command is issued. appear.

The mode switching command obtained from the disc discrimination result is sent to the access signal generating means 53. The access signal generating means 53 is configured to generate a head positioning access signal for positioning the head 25 on a predetermined track by a well-known method. In addition, a 100 track access signal generating means 53a is used as a mode switching access signal. Have equivalently. The 100-track access signal generating means 53a responds to a signal (mode switching command) indicating that the disc discriminating circuit 52 has detected a 2HD 1.44MB disc other than the 2DD type or 2HD 1.25MB type. A mode switching access signal for instructing to send 25 tracks for 100 tracks is generated.

The step direction signal generation circuit 54 connected to the access signal generation means 53 determines whether to step out or step in based on the relationship between the track on which the head 25 is currently located and the desired track to be positioned. The signal shown is formed and sent to the step direction signal input terminal 40 of the FDD 4.

The step pulse generation circuit 55 generates a step pulse corresponding to the difference between the desired track given by the access signal and the current track. In this embodiment, the head 25 is configured to move one track with one step pulse, and the number of tracks on the disk 21 is 80 in the case of a 1.44 MB disk. Therefore, when the head 25 is continuously sent from the innermost track to the outermost track on a 1.44 MB disc, 79 step pulses are generated sequentially with a predetermined period T. Further, when the step pulse generation circuit 55 receives the mode switching access signal, 100 pulses indicating that the head 25 is moved 100 tracks, which is larger than the maximum number of tracks, are arranged at a constant cycle T. A pulse train is generated as shown in the section t1 to t2 in FIG. This mode switching pulse train is sent to the step pulse input terminal 39 of the FDD 4 through the same signal line 56 as the positioning step pulse.

FIG. 5 is a block diagram showing the mode determination circuit 42 of FIG. 3 in detail. A retriggerable mono-multivibrator (MMV) 61 for detecting whether or not step pulses input to the step pulse input terminal 39 have a predetermined cycle T and are sequentially input is connected to the step pulse input terminal 39. . The output pulse width of the MMV 61 is set to Ta, which is slightly longer than the cycle T of the step pulse. Therefore, when retriggered within the time Ta, the MMV 61 continues to generate a high level output as shown at t1 to t3 in FIG. 6 (B). One input terminal of the AND gate 62 is connected to the MMV 61, and the other input terminal is connected to the step pulse input terminal 39. Therefore, the AND gate 62 passes the step pulse while the output of the MMV 61 is at the high level. A counter 63 connected to the AND gate 62 counts the step pulse passing through the AND gate 62. The reset terminal R of the counter 63 is connected to the reset MMV 64. The resetting MMV is connected to the retriggerable MMV and is triggered on the leading edge (eg, t1) of the output pulse to generate a reset pulse having a width less than the step pulse. Therefore, the counter 63 is reset at t1 in the example of FIG. 6 and starts counting clock pulses. This counter is provided with a 100-pulse output terminal 65 for detecting more than 79 pulses. An output pulse is generated from the output terminal 65 only when 100 pulses are counted, as shown at t2 in FIG. 6 (C). The output terminal 65 of the counter 63 can be changed to an arbitrary number of pulse output terminals of 80 or more. Since a maximum of 79 pulses are continuously generated during a normal seek, the counter 63 does not generate a high-level output pulse during a normal seek. This makes it possible to detect the step pulse as the mode switching information. The set terminal S of the flip-flop 66 is connected to the output terminal 65 of the counter 63, the reset terminal R is connected to the initialization circuit (reset circuit) 72, and a reset signal is supplied when the disk 25 is inserted or the power is turned on. . The output line 67 of the flip-flop 66 becomes a low level indicating the 360 rpm mode in the reset state and a high level indicating the 300 rpm mode in the set state as shown in FIG. 6 (D). The output line 67 is connected to the rotation speed switching signal input terminal 24a of the motor control and drive circuit 24 shown in FIG. The rotation speed of the motor 23 shown in FIG. 1 is switched from 360 rpm to 300 rpm as shown in FIG. 6 (E) at time t2 when the output of the mode determination circuit 42 is changed from low level to high level. The initialization circuit 72 is connected to a known disk sensor 71 for detecting the presence or absence of the disk 21. The initialization circuit 72 also outputs a reset signal when the power supply of the device is turned on.

[Operation] When the floppy disk 21 is mounted on the turntable 22 and the power switch of the FDD 4 is turned on, the motor 23 rotates. When a 2DD type or 2HD 1.25MB type formatted floppy disk is inserted as the disk 21 in the FDD 4 of FIG. 3, the motor 23 rotates at 360 rpm in accordance with the initial setting, so that the host device 1 is set to track zero T 00. When a read command is generated, the disc discriminating means 52 can discriminate between 2 DD type and 2 HD 1.25 MB type based on the media ID data of track zero. At this time, since it is not necessary to change the rotation speed of the disk 21, this speed is kept and the next operation is started.

When a 2HD 1.44 MB type formatted floppy disk is inserted as the disk 21 into the FDD 4, the disk 21 rotates at 360 rpm by default, so the host device 1 issues a track zero read command. However, the media discriminating means 52 cannot read the media ID data. Therefore, the disc discriminating means 52 discriminates that it is a 2HD 1.44 MB type and gives the result to the access signal generating means 53. As described above, the access signal generating means 53 commands the generation of the mode switching step pulse, and the step pulse generating circuit 55 continuously generates 100 pulses. The mode determination circuit 42 in FIG. 3 detects the 100 pulses, generates a mode switching signal, and the rotation speed of the disk 21 becomes 300 rpm. The host device 1 again issues a read command for track zero, reads the media ID data, and confirms the disc type. The 100 step pulse is also supplied to the stepping motor control and drive circuit 29, but the step pulse of a predetermined number or more is invalidated. Therefore, the head 25 does not move more than necessary.

As is apparent from the above, in the system of FIG. 3, automatic switching of the rotation speed is achieved without providing a manual switch for setting the rotation speed of the motor 23 at 360 and 300 rpm on the FDD 4 side. You can Further, the mode switching signal can be transmitted without providing a special line for the mode switching signal between the host device 1 and the external FDD 4. That is, the system can be configured using the existing interface, and the increase in the cost of the system can be suppressed.

[0023]

Second Embodiment Next, a system according to a second embodiment of the present invention will be described with reference to FIGS. However, in FIGS. 7 to 10, the same parts as those in FIGS. 1 to 6 are designated by the same reference numerals and the description thereof will be omitted. In the FDD 4a of the second embodiment, the disk sensor 71 is not connected to the initialization circuit 72 as shown in FIG. Therefore, the mode determination circuit 4a is not initialized even if the disk 21 is replaced. Therefore, the number of rotations when the disc 21 is inserted is indefinite. In order to deal with this point, as shown functionally in FIG. 7, the access signal generating means 53 of the host device 1 includes two 100 track access signal means 53a and 150 track access signal generating means 53b. Further, as shown in FIG. 7, part of the FDD 4a is modified. Next, each part will be described in detail.

The access signal generating means 53 in the host device 1 shown in FIG. 8 has 100 tracks for giving a rotation command of 300 rpm of the disk 21 and 150 tracks for giving a rotation command of 360 rpm. Access signal generating means 53b. The operation of the other parts in FIG. 8 is substantially the same as that in FIG.

The initialization circuit 72 a of FIG. 7 is not connected to the disk sensor circuit 71. Therefore, the initialization circuit 72a outputs the reset signal only when the power source of the FDD 4a is turned on. The mode decision circuit 42a shown in FIG. 7 operates in the normal seek mode for the 100 pulse trains and the 150 pulse trains sent based on the 100 and 150 track access signal generating means 53a, 53b of the host device 1. The pulse is discriminated and detected, and the setting of 300 rpm and 360 rpm is performed. FIG. 9 shows the mode decision circuit 42a of the second embodiment. The retriggerable MMV 61 of FIG. 9 has the same configuration as that of FIG. 5, and is connected to the step pulse input terminal 39. The clock input terminal CK of the counter 63a is connected to the step pulse input terminal 39, and the clear terminal CLR is connected to the retriggerable MMV61. The counter 63a has a cycle T and has a first output terminal 65 which generates an output pulse when counting 100 pulses which are continuously input and a second output terminal which generates an output pulse when counting 150 pulses. 68 and. The D-type flip-flop 66a at the subsequent stage of the counter 63a has a data input terminal D connected to the ground, a clock input terminal CK connected to the second output terminal 68 of the counter 63a, and a first input terminal of the counter 63a. Of the output terminal 65, a preset terminal PR connected to the initialization circuit 72a, and an output terminal Q connected to the output line 67.

The operation of the system of the second embodiment will be described below. When the power is turned on, a reset pulse is given to the clear terminal CL of the flip-flop 66a. Therefore, the flip-flop 66a is in the reset state, and the output terminal Q becomes the low level indicating the disk rotation of 360 rpm. The host device 1 reads the media ID data of track zero of the mounted disk 21. If it is read, it is judged that the disk 21 has a rotational speed suitable for this medium (disk), and the speed switching of the motor 23 of the FDD 4a is not executed. On the other hand, when the media ID data cannot be read, first, the host device 1 creates a first mode switching pulse train consisting of 100 step pulses, and the step pulse input terminal 39 of the FDD 4 a is connected to the step pulse input terminal 39 of FIG. It is given as shown in the section from t1 to t2. The mode decision circuit 42a of the FDD 4a detects 100 pulses by the counter 63a of FIG. 7, and generates a pulse at the first output terminal 65 of the counter 63a at t2 of FIG. 10C, which is the flip-flop 66a. It is given to the preset terminal PR, and this output terminal Q becomes high level at t2 as shown in FIG. When the flip-flop 66a is in the reset state before t3, the flip-flop 66a is set at t3 and the motor 23 rotates at 300 rpm from t3. As a result, it becomes possible to read the media ID data from the track zero of the disc.

After that, the disk 21 is replaced shortly before the time point t4 in FIG. 10, and if a 2 HD 1.25 MB type disk is inserted, for example, the rotational speed of this disk is the same as the previous setting state. Since it is 300 rpm, the host device 1 cannot read the media ID data. Therefore, the disc discriminating means 52 of FIG. 8 sends a signal to the access signal generating means 53 instructing to switch to a mode different from the conventional one. In response to this, a 150 track access signal is generated from the 150 track access signal generating means 53b, and the step pulse generating circuit 55 generates 150 pulses at a cycle T as shown by t4 to t6 in FIG. appear. The mode determination circuit 42a of the FDD 4a detects the 150 pulses by the counter 63a and generates a high level pulse from the second output terminal 68 at t6 to t7 in FIG. 10 (D). The flip-flop 66a reads the low level of the data input terminal D by using the leading edge of the pulse of FIG. 10 (D) as a clock, and the output terminal Q is changed to the low level at t6 as shown in FIG. 10 (E). Then, a command of 360 rpm is given to the motor control and drive circuit 24. When the disk 21 rotates at 360 rpm, the media ID data can be read, and then the data conversion is performed while keeping this rotation speed. Therefore, also in this embodiment, the same operational effect as in the first embodiment can be obtained.

The invention is not limited to the embodiments described above, for example a retriggerable MMV 61 can be constructed with a combination of a count and a latch.

[Brief description of drawings]

FIG. 1 is a block diagram showing a computer system of a first embodiment.

FIG. 2 is a block diagram showing a configuration of a host device of FIG.

FIG. 3 is a block diagram showing the external FDD of FIG.

FIG. 4 is a block diagram showing functionally divided means for generating a mode switching signal in the host device of FIG.

5 is a block diagram showing the mode determination circuit of FIG. 3 in detail.

FIG. 6 is a waveform diagram showing changes in the states of the respective parts in FIG. 5 and the disk rotation motor.

FIG. 7 is a block diagram showing a computer system of a second embodiment.

FIG. 8 is a block diagram functionally showing a host device according to a second embodiment.

9 is a block diagram showing in detail the mode determination circuit of FIG.

FIG. 10 is a waveform diagram showing each part of FIG.

[Explanation of symbols]

 1 Host device 4 External 3 mode FDD 42 Mode determination circuit

Claims (1)

[Scope of utility model registration request] 1. A disk rotation motor for rotating a plurality of types of floppy disks, and a rotation speed switching signal input terminal connected to the disk rotation motor and switching the rotation speed. In response to a rotation speed switching signal input to a signal input terminal, a motor drive circuit for rotating the disk rotation motor to a plurality of rotation speeds, and signal conversion by relative scanning motion of the floppy disk. A signal conversion head for performing the above, a read circuit connected to the signal conversion head, a head moving device having a stepping motor for moving the signal conversion head in the radial direction of the disk, the stepping motor A step pulse input terminal for driving the step pulse input terminal, is connected between the step pulse input terminal and the rotation speed switching signal input terminal, A series of floppy disks having a maximum number of tracks but having a predetermined number of step pulses greater than the number of step pulses required to move the signal transducing head to be able to traverse all tracks. Detecting that a rotation speed switching step pulse train is input to the step pulse input terminal to form the rotation speed switching signal, and the rotation speed switching signal to the rotation speed switching input terminal of the motor drive circuit. A floppy disk device having a rotation mode determination circuit for providing the same.