JPS6318577A - Control system for medium drive device by cpu - Google Patents

Abstract

PURPOSE:To read a recording medium recorded in a conventional density in plural recording density floppy disk devices and to maintain the compatibility of a software by disposing a switching circuit for selectively switching and connecting a medium drive device to any of first and second medium control circuits. CONSTITUTION:When a medium change signal holding circuit is provided, and the first medium is loaded in the drive device, a CPU 2 controls the drive device through the first medium control circuit 3 and when the second medium is loaded, the CPU 2 controls the drive device through the second medium control circuit 6. When the loaded medium is exchanged with other medium, the output of the medium change signal indicating that from the drive device is recognized by the CPU 2 through the second medium control circuit 6, and as a result, even when the medium change signal is reset, if the CPU 2 tries to control the drive device through the first medium control circuit, a medium change signal holding circuit functions to hold the medium change signal without being rest in the first medium control circuit 3.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a control system for a medium drive device using a CPU (Central Processing Unit).
The present invention relates to a control system for a floppy disk device used as an auxiliary storage device in an electronic computer system.

[Conventional technology]

Conventionally, as a system that can selectively reproduce any recording medium recorded at different recording densities using the same floppy disk device, for example, Japanese Patent Laid-Open No. 60-87
There are known systems, such as the system described in Publication No. 405, that change the rotational speed of the floppy disk, the write current value to the magnetic head, the characteristics of the read signal, etc. using a switching signal according to the recording density of the disk to be reproduced. It is being According to this, two types of recording media recorded at two different recording densities (conventional density I, conventional density ■) as shown in Table 1 below can be selectively played back by the same floppy disk device. It becomes possible to do so.

Table 1 When a floppy disk device is used as an auxiliary storage device in an electronic computer system, a floppy disk control circuit is required to control the floppy disk device.

Regarding a floppy disk control circuit when using a floppy disk device that can reproduce a recording medium recorded at any of a plurality of recording densities with the same floppy disk device, the above-mentioned known example is used. Although this is not disclosed in the above, it is easily possible to do so by adopting a circuit configuration as shown in FIG. This will be explained below as a conventional technique.

In FIG. 9, 101 is a system bus of a computer system using a floppy disk device. 10
3 is a floppy disk controller (hereinafter referred to as FDC) for controlling the floppy disk device; for example, (7) FDC-LS I manufactured by NEC Corporation
, μPD765Ac, etc. may be used. 104 is FD
A direct memory access controller (hereinafter referred to as DMA) is used to transfer data at high speed between the C103 and a memory (not shown) connected to the system bus 101.
controller). FDCl 03, DMA
The system controller 104 and bus 102
Connected to bus 101. 106 is a data separator circuit for separating the signal 107 read from the Flo Novi Disk Device (hereinafter referred to as FDD) 105 into a data signal and a clock signal, and the FDC 103 is a data separator circuit for separating the signal 107 read from the Flow Novi Disk Device (hereinafter referred to as FDD) 105 into a data signal and a clock signal. signal 109
connected by.

110 is a write data signal that sends data to be written to FDD 105, and 111 is the rotational output signal of FDDIO5.
N, F for turning off, moving the head, switching, etc.
DD control output signal, 112 is FDD I O5
The FDD control input signal receives track position information and signals indicating the status of the FDD 105 from the FDD 105 .

The input boat 113 is an FDD input from the FDD 105.
The output port 115 is for receiving the signal 114 which the FDC 103 cannot directly receive among the control input signals 112, and the output port 115 is for receiving the signal 114 which the FDC 103 cannot directly receive among the control input signals 112.
3 outputs a signal 116 that cannot be directly controlled.

117 is an FDD interface for connecting signals for controlling these FDDs 105 to the FDD 105, and is usually composed of a receiver and a driver.
34 floppy disk control signals 11 between
Connected at 8.

When using a floppy disk device capable of reproducing a recording medium recorded at any one of the plurality of different recording densities described above, the floppy disk control signal 118 is used.
A switching signal for switching the recording density is output from the output boat 115 through 116 into the FDD.
In the IO5, the rotation speed, the value of the write current, the characteristics of the read signal, etc. are changed based on this switching signal.

This switching signal is also input to the data separator circuit 106, and the data separator circuit 106 operates at a data transfer rate corresponding to each recording density.

In order to increase the capacity of floppy disk devices, recording media capable of recording at even higher recording densities have appeared. density FDD) has been proposed and known.

Table 2 In these high recording density FDDs, in order to increase the recording density, the data transfer rate is, for example, twice as high as the conventional one in the case of high recording density ■, and ten times as high as that of the conventional one in the case of high recording density ■. There is.

The data transfer rate available with FDC is typically 5Q
It is technically impossible to use the FDC to control a high recording density floppy disk device (high recording density FDD>) as described above.

Therefore, as a high recording density floppy disk control circuit for controlling these high recording density FDDs that transfer data at high speed, a hard disk controller for controlling a fixed magnetic disk device is used instead of an FDC. (hereinafter referred to as IDC).

In this case, the configuration of the high recording density floppy disk control circuit may be as shown in Figure 1O.
In this case, the FDCIO 3 in FIG. 9 is replaced with an HDC 119, and the data separator circuit 106 is replaced with a data separator circuit 120 for high recording density.

The clock generation circuit 121 supplies clocks to the HDC 119 and the data separator circuit 120 for high recording density. The HDC 119 and the high recording density data separator circuit 120 are connected by a high recording density read signal 122 and a high recording density data separator circuit control signal 123.

Similar to the conventional density floppy disk control circuit, the signals that control the high recording density FDD 125 are
The interface 126 is connected through a high density floppy disk control signal 127.

Consider the case where this high recording density FDD 125 is connected to a computer system using a conventional floppy disk device as shown in FIG. 11(a).

Here, in FIG. 11, 12B is a conventional density floppy disk control circuit, 129 is a conventional density floppy disk device control signal, and 130 and 131 are both controlled by a floppy disk control circuit 128. Conventional density floppy disk drive, FDDI
, FDD2 (the case where two are connected is shown as an example). High recording density FDDI25 that can be used with high recording density in the computer system shown in FIG. 11(a)
When connected, a configuration as shown in FIG. 11(b) is obtained.

Here, 132 is a high recording density floppy disk control circuit that transfers data at high speed, 133 is a high recording density floppy disk device control signal, and 134 and 135 are all connected to the high recording density floppy disk control circuit 132. High recording density FDD1 and high recording density FDD2 (-
As an example, the case where two are connected is shown).

This makes it possible to use recording media recorded at high recording density in computer systems, but conventional density FDDs (11130, FDD (2) 131 and high recording density FDI) g134, high recording density FDD f2+13
Since it is necessary to have a separate electronic computer system for each of 5 and 5, problems remain in terms of cost, installation space, and ease of imitation.

Therefore, by using an FDD (hereinafter referred to as a multiple recording density FDD) that can be selectively used for both high recording density disks and conventional density disks, we have created the configuration shown in FIG. 11(c). Multiple recording density FDD (1) 1
38, Multiple recording densities FDD f2) 139 allows the use of recording media recorded at either high recording density or conventional density, but it is not possible to transfer data at the high speed mentioned above. Since the format of the recording medium is different between the HDC that is possible and the FDC used in conventional floppy disk control circuits, the conventional
By controlling the floppy disk control circuit 128 in the computer system shown in FIG. 1(a), F D D f
l) The software used for the 130, FDD (211jl) could no longer be used with the computer system shown in FIG. 11(c), and it was impossible to maintain software compatibility.

In other words, the multiple recording density FD shown in FIG. 11(c)
The multiple recording density floppy disk control circuit 136 for D (138, 139) and the floppy disk control circuit 128 for the conventional density FDD (130, 131) shown in FIG. 11(a) are technically different. Therefore, the software for both CPUs had to be different.

[Problem that the invention seeks to solve]

Therefore, the present invention provides a floppy disk control circuit for conventional density FDDs and a multi-recording density floppy disk ft control circuit for multi-density FDDs, which are, as a practical matter, a common control circuit when viewed from the CPU. The problem to be solved is to make it possible to have compatibility by making the software for the re-control circuit by the CPU common by devising the circuit configuration so that it can be handled as described above. It is marked as a point.

Accordingly, it is an object of the present invention to provide a CPU-based control system for a medium drive device that enables the above-mentioned operations.

Means for Solving Problem C] In order to achieve the above object, the present invention provides a method for a medium recorded at any of a plurality of different recording densities.
a medium drive device that accepts and drives this and enables reproduction thereof; and a first medium recorded at a first density among the plurality of different recording densities is reproduced by the drive device; a first medium control circuit for performing control; and a first medium control circuit for performing control when a second medium recorded at a second density among the plurality of different recording densities is reproduced by the drive device. a second medium control circuit; a switching circuit that selectively connects the medium drive device to one of the first and second medium control circuits; CPU connected to each
(central processing unit);
When a medium is loaded, the CPU controls the drive device through the first medium control circuit, and when a second medium is loaded, the CPU controls the drive device through the second medium control circuit. In a CPU-based control system for a medium drive device, a medium change signal holding circuit is provided, and improvements are made to the control program in connection with the management of the track position of the head on the medium in the medium drive device. .

[Effect]

In the medium drive device, when the loaded medium is replaced with another medium, a medium change signal indicating this is outputted from the drive device by the CPU via the second medium control circuit. Even if the medium change signal is recognized and the medium change signal is reset as a result, the next time the CPU attempts to control the drive device through the first medium control circuit, the medium change signal is In the circuit, the medium change signal holding circuit functions as if it were held without being reset. Further, by means of the control program, the first medium control circuit manages the trunk position of the head on the medium in the medium drive device, and the second medium control circuit temporarily manages the trunk position of the head on the medium in the medium drive device. At that time, the current head position is memorized, the seek is performed to perform the desired processing, and after the processing is completed, a control operation is performed to return the head to the starting track position, and the second medium control circuit As such, head track position management itself is not performed.゛Thus,
It is possible to avoid confusion when the first medium control circuit and the second medium control circuit independently manage the track position of the same head.

〔Example〕

Hereinafter, one embodiment of the present invention will be described in detail with reference to the drawings.

FIG. 1 is a block diagram showing the configuration of an embodiment of the present invention. In the same figure, ■ is the system bus of the computer system, 2 is the central processing unit (hereinafter referred to as CPU) of the computer system, and 3 is the CPU through the system bus l.
A first floppy disk control circuit 4 controls a conventional density floppy disk device connected to a floppy disk device connected to the conventional density floppy disk device. A disk device control signal for controlling the device; 5 is a multi-recording density floppy disk device capable of selectively reading both a recording medium recorded at a conventional density and a recording medium recorded at a high recording density; 6 is a second flow for controlling the multi-recording density floppy disk device 5 when reading a high recording density recording medium;

7 is a high recording density floppy disk device control signal for controlling the multiple recording density floppy disk device 5 at high recording density; 8 is a floppy disk to which the floppy disk device control signal 4 is connected; 9 is a floppy disk device control signal control circuit for controlling the floppy disk device control signal 4; IO is a conventional density floppy disk device control signal;
12 is a switching signal generation circuit for generating a switching signal 13 for switching between conventional density and high recording density;
4 is a floppy disk device control signal switching circuit that switches between the conventional density floppy disk device control signal lO and the high recording density floppy disk device control signal 7 according to the instruction of the switching signal 13; 15 is a floppy disk device control signal switching circuit; Conventional density floppy disk drive side switched output by circuit 14? This is a multiple recording density floppy disk device control signal consisting of either signal 11 signal 10 or high recording density floppy disk device control signal 7.

When the CPU 2 managing the system bus 1 reads a recording medium recorded at conventional density by the multi-density floppy disk device 5, it does this by controlling the first floppy disk control circuit 3.

Under normal conditions, the switching signal generation circuit 12 generates the switching signal 13 such that the floppy disk device control signal switching circuit 14 connects the conventional density floppy disk device control signal IO to the multiple recording density floppy disk device control signal 15. is occurring. For this reason, the first
By controlling the floppy disk control circuit 3, the CPU 2 can use the multi-recording density floppy disk device 5 in a state in which a recording medium recorded at a conventional density can be read.

Next, a case will be described in which the multiple recording density floppy disk device 5 reads a recording medium recorded at a high recording density.

First, the CPU 2 controls the switching signal generation circuit 12 to generate a switching signal 13 so as to switch the switching circuit 14 to the side used at high recording density. This switching signal 13 is supplied to a floppy disk device control signal control circuit 9 and a floppy disk device control signal switching circuit 14.

The floppy disk device control signal switching circuit 14 includes:
When the switching signal 13 is input, high-density floppy
The disk drive control signal 7 is connected to the multi-density floppy disk drive control signal 15.

Further, the floppy disk device control signal control circuit 9 receives the floppy disk device control signal 4 through the floppy disk device control signal connection terminal 8 from the floppy disk device control signal 4 for conventional density floppy disks when viewed from the first floppy disk control circuit 3. - Control so that the disk device looks the same as if it were connected as a multi-recording density floppy disk device 5. The details will be described later.

This enables the CPU 2 to read a high recording density recording medium in the multiple recording density floppy disk device 5.

A specific example of the configuration of the second floppy disk control circuit 6 is shown in FIG. In the figure, a hard disk controller 16 (hereinafter referred to as HDC) performs various controls B for the floppy disk device 5. For example, μPD7261AD manufactured by NEC Corporation is used for this purpose. 18 is a high recording density data separator circuit corresponding to reading of a recording medium recorded at high recording density, and receives data 19 read from the multiple recording density floppy disk device 5 through the floppy disk device control signal switching circuit 14. The data is separated into black and white data and sent to the HDC 16 through the signal line 20.

The clock generation circuit 17 supplies clocks to the HDC 16 and the high recording density data separator circuit 18. 21 is HD
C16 outputs various control signals necessary when the multi-recording density floppy disk device 5 is used at a high recording density. This includes, for example, head selection, a signal instructing head movement, write data, and the like.

Further, numeral 22 inputs various signals from the multi-recording density floppy disk device 5. This includes, for example, a signal indicating the status of the multi-recording density floppy disk device 5, an index signal which outputs a pulse every time the multi-recording density floppy disk device 5 rotates the recording medium once, and the like.

23 is an output port for outputting a signal 24 which is a signal for controlling the multi-recording density floppy disk device 5 and cannot be directly controlled by the HDC 16.

This includes, for example, a signal that instructs the motor to turn 0N10FF.

25 is an input port for inputting a signal 26 which cannot be directly received by the HDClG among the signals outputted by the multiple recording density floppy disk device 5. This includes, for example, a disk change signal indicating that a recording medium has been physically exchanged with another medium in the multi-density floppy disk device 5. These floppy disk device control signal switching circuits 14
The signal connected to is the high recording density floppy disk device control signal 7.

Usually, a floppy disk controller (hereinafter referred to as FDC) is used to control a floppy disk device. However, the data transfer rate that can be used with FDC is less than 500 kbit/sec, and in high-density floppy disk devices that record data at high recording density, the data transfer rate can reach from IMbit/sec to 5 Mbit/sec. FDC cannot be used. For this purpose, an HDC whose control signal structure is similar to that of an FDC is used.

However, there is a difference in the format of recording media between FDC and HDC, and a recording medium written using FDC cannot be read using HDC. Conversely, a recording medium written using HDC cannot be read using FDC.

FIG. 3 shows an example of the format of a recording medium used in the HDC 16.

In the figure, reference numeral 27 is an index signal, and the circumference of the recording medium from one index signal 27 to the next index signal 27 is one track. A trunk is divided into units called sectors and managed.

1 sector is a sink 34, an ID address mark 28 representing the start of the D area indicating the attribute of the sector, a track #29 that stores the track number, a head #30 that stores the head number, and a sector number. Sector #31, ■ DTM area CRC (Cyclic Re
4CRC3 that stores the dundancy check)
2. tlD-pAD 33 indicating the end of the IDfiJI area, sink 34, data address mark 35 indicating the start of the data area, data 36 which is the area for recording data.
, ECC (Error Check) is used to detect and correct read errors when reading data 36.
and Correct ) 37, DATA-PAD3 B indicating the end of the data area, and a gap (3) 39 between sectors to absorb deviations in writing position due to rotational fluctuations, and furthermore, a gap (3) 39 indicating the beginning of one track. At the end, there is a gap (114G) and a gap (4
) 41 exist.

Next, floppy disk device control signal switching circuit 1
An example of the configuration of No. 4 is shown in FIG. Conventional density 70 TPI disk drive control signal 10 has an output signal and an input signal. The output number δ is the data to be written, and the motor is ON.
There are signals for instructing /OF, signals for moving and selecting a magnetic head, signals for selecting a floppy disk device, etc.

Input signals include signals indicating the status of the floppy disk device, read data, and when the magnetic head is at track 0.
There are signals indicating that the recording medium is at the position of the recording medium, signals indicating that the recording medium has been replaced, etc.

FIG. 4(a) shows an example of a switching circuit for the output signal of the conventional density floppy disk device control signal 1O.A terminal 42 is connected to the output signal of the conventional density floppy disk device control signal 10. Further, the output signal of the high recording density floppy disk device control (No. 3 7) is connected to the terminal 43. The switching signal 13 is also connected to the terminal 44.

In floppy disk devices, a single floppy disk control circuit normally controls a plurality of floppy disk devices by means of a daisy chain connection.

For this reason, a terminating resistor is required for the output signal of the floppy disk control circuit, and the resistor 45 corresponds to this. However,
Necessary if not only the floppy disk device control signal connection terminal 8 but also a conventional density floppy disk device is connected to the first floppy disk control circuit 3, and a terminating resistor is connected. do not have.

46 is a line receiver of the type that inverts the signal, and is usually of the Schmitt trigger type.

Terminal 42. Terminal 43. The reason why only the signal input from terminal 42 among the signals input from terminal 44 is inverted is because the floppy disk drive control I signal 4 is normally an active low signal.

The circuit 47 is a two-man powered data selector which outputs either the human powered signal A or the signal inputted to the input B to the output Y in accordance with the select signal S.

Here, when the select force S is high level (“1”), the signal input to input B is output to output Y, and when the select force S is low level (“O”), the signal input to input A
This outputs the signal input to the output Y.

48 is a line driver with inverted output (active
A signal selected by the circuit 47 is output to the terminal 49 as low), and the multiple recording density floppy disc device 5
connected to.

Further, FIG. 14(b) is an example of a switching circuit for the input signal of the conventional density floppy disk device control signal IO. A multi-recording density floppy disk device control signal from the multi-recording density floppy disk device 5 is connected to the terminal 50 .

51 is a line receiver, and an inverted signal is input to input I of the selector circuit 52. The selector circuit 52 outputs the signal input to the input I to either the output O1 or the output 02 according to the select signal S. Terminal 55 is an input signal for high recording density floppy disk device control signal 7, and terminal 56 is connected to switching signal 13. In addition, the output 01 of the selector circuit 52 is passed through the line driver 53 as an inverted output to the terminal 54.
It is output to the conventional density f0.7 PI disk device control signal 10.

FIG. 14(c) shows an example of the configuration of the selector circuit 52. 2 AND gates 59.60 and 1 inverter 5
8, and when a high level (“1”) signal is input to the select input (S) 63, the input 157
The signal input to input +57 is output to (02) 62, and if a low level (“0”) signal is input to select input (S) 63, the signal input to input +57 is output (
01) Output to 61. The output that is not selected by the select input (S) 63, for example, output (01)
When the input signal of input (1) 57 is output to 61, the output of output (02) 62 always maintains a low level.

Next, a method of moving a magnetic head (not shown) on the disk in the multiple recording density floppy disk device 5 will be explained.

In a floppy disk device, the operation of moving the magnetic node to the desired track position on the disk is called seek. Normally, when a computer system is started up, the magnetic head is first moved to the outermost track O position,
Thereafter, a seek to the target track is performed using this track 0 as a reference.

The FDC and HDC have an internal track counter for counting track numbers, and automatically move the magnetic head to a designated track.

By the way, in the embodiment of the present invention shown in FIG.
When reading a recording medium recorded at a conventional density using a multi-density floppy disk device 5, the FDC of the first floppy disk control circuit 3 also reads a recording medium recorded at a high recording density. When this is performed in the multiple recording density floppy disk device 5, it is performed by the HDC 16 of the second floppy disk control circuit 6, but the magnetic head on the disk in the multiple recording density floppy disk device 5 is currently A problem arises in managing which track is located.

That is, the track position management of the magnetic head on the disk in the multi-density floppy disk device 5 is performed both on the side of the first floppy disk control circuit 3 and on the side of the second floppy disk control circuit 6. If an attempt is made to do this without permission, confusion will occur and it will become virtually impossible to manage the trunk position of the magnetic head.

- Therefore, in the present invention, the track position is managed by the FDC of the first floppy disk control circuit 3, and the second floppy disk control circuit 6 does not manage the track position. Instead, according to the procedure shown in FIG. 5, the magnetic head is moved to the target track, ie, seek is performed whenever the need arises.

By doing this, there is no need to modify the software for controlling the first floppy disk control circuit 3.

Please refer to FIG. The HDC 16 of the second floppy disk control circuit 6 sets 0 in the square counter (step 64), and then seeks toward the outer circumference one track at a time until the magnetic head reaches the track 0 position (step 65).・The operation of performing an out operation (step 66) and adding 1 to the count (step 67) is repeated.

Whether the magnetic head has come to the track O position is determined by a signal indicating that the magnetic head having the width of the multi-recording density floppy disk device control signal 15 is output from the multi-recording density floppy disk device 5 and is at the track O position. This is done by checking.

When the magnetic head reaches the position of track 0, a desired processing operation is performed (step 68). The desired processing operation here refers to data reading including seeking, data recessing, and the like. For example, when reading data, the HDC 16 seeks to the target track and reads the data, and the HDC 16 seeks to the position of track O.

When the desired processing is completed, a step-in operation is performed in which the magnetic head is sought one track at a time toward the inner circumference until the counter reaches O (step 69), and 1 is subtracted from the counter (step 71). Repeat the action. When the counter reaches 0 here, the seek season is over (
Step 72).

In other words, when the CPU 2 uses the multi-density floppy disk device 5 to read a recording medium recorded at a high recording density, it first memorizes the current position of the magnetic head and then performs a seek operation. After the process is completed,
The magnetic head is returned to the position of that track.

By causing the second floppy disk control circuit 6 to perform seek in this way, the first floppy disk control circuit 3 allows the second floppy disk control circuit 6 to
It becomes possible to control the multi-recording density floppy disk device 5 in exactly the same way as if it were not connected, and therefore there is no need to modify the software.

Next, in the multiple recording density floppy disk device 5,
When the recording medium is replaced, the multiple recording density floppy disk device 5 outputs a signal indicating this. How to handle this signal according to the present invention will be explained.

The timing of the signal indicating the replacement of the recording medium is set to 6th.
This timing diagram, shown in Figure 1, is for multiple density floppy
5 is a timing chart as an example of a signal outputted by the disk device 5 as a multi-recording density floppy disk device control signal 15. FIG.

In FIG. 6, when the CPU 2 selects the multi-density floppy disk device 5 for reading data or writing data, 73 indicates the first floppy disk control circuit 3 or the second floppy disk device 5. -Drive-5el output from the disk control circuit 6
The ect signal is seen on the multi-density floppy disk device control signal 15 and is an active low signal.

74 is the time since the multiple recording density floppy disk device 5 was selected last time, that is, Drive-S elect
Disk-Change signal output from the disk device 5 when the recording medium is replaced after the t signal 73 is input until the next multi-recording density floppy disk device 5 is selected. is seen on the multi-density floppy disk device control signal 15, and is an active low signal.

Further, 75 is a DCHG-Reset signal for resetting the output [)1ll(-Change signal 74, which is output from the first floppy disk control circuit 3 or the second floppy disk control circuit 6. .

The timing will be explained below.

In FIG. 6, it is assumed that the recording medium has been replaced at the point where the vertical dotted line is drawn (timing 76.82). First, when the multiple recording density floppy disk device 5 is selected (timing 77), before that Because the recording medium is replaced in (timing 76), Disk-Cha
nge signal 74 is output (timing 78).

In this state, when the DCHG-Reset signal 75 is output, at the rising edge (timing 79), the Disk-C
The hang signal 74 is reset and no longer output.

Also, from the input of the previous Drive-S select signal 73 (timing 77) to the current Drive-S select signal 73
If the recording medium is not replaced before the input of the select signal 73 (timing 81), D 1
The sk-Change signal 74 is not output.

Also, the Drive-5 select signal 73 is input (timing 80) and the Disk-Chang
While the e signal 74 is being output (timing 83),
Dis if DCHG-Reset signal 75 is not input.
The k-Change signal 74 remains output.

The signal output when such a recording medium is replaced is used to improve processing speed in a computer system using a floppy disk device.

When this recording medium is replaced, the signal output from the multiple recording density floppy disk device 5 is also controlled in the floppy disk device control signal control circuit 9 in the embodiment of the present invention. , is controlled by the circuit shown in FIG.

This is because the signals that are output when this recording medium is replaced are inputted separately to the first floppy disk control circuit 3 and the second floppy disk control circuit 6. This is because there is a risk of malfunction.

For example, in the multiple recording density floppy disk device 5 by the floppy disk control circuit 3 of Kintei 1,
Assume that data is read from a recording medium recorded at a conventional density. Next, the recording medium is replaced, and then the second floppy disk control circuit 6 reads data from the recording medium recorded at high recording density in the multiple recording density floppy disk device 5.

At this time, a signal indicating that the recording medium has been replaced is output from the multiple recording density floppy disk device 5. Now, suppose that the second floppy disk control circuit 6 has learned the signal indicating that the recording medium has been replaced, and has reset it because it is no longer used.
Next, when the first floppy disk control circuit 3 attempts to read data from the recording medium recorded at the conventional density in the multiple recording density floppy disk device 5 without replacing the recording medium, From the point in time when the floppy disk control circuit 3 selects the multiple recording density floppy disk device 5, even though the recording medium has been replaced, the signal indicating this has already been sent to the second floppy disk control circuit 3. Since it has been reset by the circuit 6, a signal indicating that the recording medium has been replaced is not outputted, so that the first floppy disk control circuit 3 makes an erroneous determination. To prevent this, a circuit as shown in FIG.
It is provided in the floppy disk device control signal control circuit 9 shown in the figure.

This will be explained below. In FIG. 7, reference numeral 84 denotes a signal FD-Drive for selecting the multiple recording density floppy disk device 5 output from the first floppy disk control circuit 3.
-5elsct signal and is an active high output.

85 indicates that the recording medium from the multiple recording density floppy disk device 5 input to the first floppy disk control circuit 3 has been replaced.
This is the k-Change signal and is an active high output. 86 is a signal output from the first floppy disk control circuit 3, which is an FD for resetting the FD Disk-Change signal indicating that the recording medium output from the multiple recording density floppy disk device 5 has been replaced. -DCHG -Re5et signal and active high output.

FD-Drive-5 select signal 84.
FD-Disk-Change signal 85. FD-
The DCHG-Reset signal 86 is part of the signals connected to the floppy disk drive control signal control circuit 9 by the conventional density floppy disk drive control signal IO in FIG. 87 is HD-Drive-5els for selecting the multiple recording density floppy disk device 5 output by the second floppy disk control circuit 6;
ct signal, which is an active high output, and is connected by the high recording density floppy disk device control signal 7.

Further, 88 is a signal D indicating that the recording medium output from the multiple recording density floppy disk device 5 has been replaced.
The isk-Change signal is an active high output and is connected to the floppy disk drive control signal switching circuit 14 through the conventional density floppy disk drive control signal 10.

89 is a D type flip-flop circuit.

The operation of the circuit shown in FIG. 7 that controls the signal indicating that the recording medium has been replaced will be explained with reference to FIG. 8.

In FIG. 8, reference numeral 90 is an HD-Disk-Change signal that is manually input to the second floppy disk control circuit 6 and indicates that the recording medium from the multiple recording density floppy disk device 5 has been replaced. Active high output. Reference numeral 91 denotes a signal output from the second floppy disk control circuit 6, which is used to reset the signal indicating that the recording medium output from the multiple recording density floppy disk device 5 has been replaced.
-D CHG -Re5et signal and active high output.

HD-Disk-Chsnge signal 90. HD-
Although not shown in FIG. 7, the DCHG-Re5et signal 91 is connected to the floppy disk device control signal switching circuit 14 and the second floppy disk through the high recording density floppy disk device control signal 7 in FIG. This is a signal that is input/output to/from the control circuit 6. 92 is the Q output of the D type flip-flop 89 in FIG.

First, assume that the recording medium is replaced in the multiple recording density floppy disk device 5 at timing 201. Then,
At timing 203, the first floppy disk control circuit 3 controls the FD in order to read the recording medium recorded at the conventional density in the multiple recording density floppy disk device 5.
-Drive -5elsct signal 84 is output (timing 203).

At this time, since the recording medium is replaced at timing 201, the FD-Disk-Change signal 85 is outputted through the OR gate 96 and the AND gate 95. In this state, the FD-DCHG-Reset signal 86
When the FD-Disk-Change signal 85 is input, the FD-Disk-Change signal 85 is reset. 'This means that the FD-DCHG-Reset signal 86 is sent from the conventional density floppy disk device control No. 13 IO to the floppy disk drive.
Since the signal is input to the multi-recording density floppy disk device 5 through the disk device control signal switching circuit 14, as explained in FIG. This is because it will be reset.

Next, at timing 202, the recording medium is replaced, and then at timing 209, the second floppy disk control circuit 6 attempts to read the recording medium recorded at a high recording density in the multiple recording density floppy disk device 5. The HD-Drive-5 select signal 87 is output.

Then, at timing 202, since the recording medium has been replaced, an HD-Disk-Change signal 90 is output. At this time, the CK multiplied signal of the D type flip-flop 89 is input through the AND gate 94, and the output Q
(92) becomes high level (timing 206).

In this state, the second floppy disk control circuit 6
- When the DCHG-Reset signal 91 is output (timing 207), the HD-Disk -Change signal 90
is reset in the same manner as described above.

Next, the first floppy disk is loaded without replacing the recording medium.
It is assumed that the disk control circuit 3 reads a recording medium recorded at a conventional density in the multiple recording density front disk device 5.

Similarly to the above, the first floppy disk control circuit 3 outputs the FD-Drive-5 select signal 84. At this time, the multiple recording density floppy disk device 5 does not output a signal indicating that the recording medium has been replaced, but the Q output 9 of the D type flip-flop 89
2 is high level, OR gate 96, AND
FD-Disk-Change through gate 95
Signal 85 is output (timing 211).

When the FD-DCHG-Reset signal 86 is input in this state (timing 212), the FD-Drive
-3elect signal 84 is also input, so NAND
An active low signal is output through the gate 93 and input to the CLr1 input of the D-type flip-flop 89, the Q output 92 is cleared and becomes low level (timing 213), and the FD-Disk-Change signal 85 is reset and output. It will no longer be done.

As described above, according to this embodiment, an electronic computer system having a conventional density floppy disk control circuit can be
When connecting a multi-density floppy disk device that can read both a high-density recording medium that transfers data at high speed and a recording medium recorded at a conventional density, it is possible to record at a conventional density. Since the conventional floppy disk control circuit can be used as is when reading the recorded recording medium, the installation space can be reduced and the floppy disk control circuit can be used to control multiple recording density floppy disk devices. No special circuit is required to read out recording media recorded at conventional densities, which reduces costs and allows for multi-density floppy disks.
When reading a recording medium recorded at a conventional density using a disk device, it is possible to use a conventional floppy disk control circuit, which provides excellent operability. , it is possible to read a recording medium recorded at a conventional density in a multi-density floppy disk device, and software compatibility can be maintained.

〔Effect of the invention〕

According to the present invention, when controlling a multiple recording density floppy disk device that is capable of reading both a recording medium recorded at a high recording density and a recording medium recorded at a conventional density,
The conventional density floppy disk control circuit connected to the computer system can be used as is to read the conventional density floppy disk, which saves installation space and is easy to operate. No changes are required to the software that controls the control circuit.
It has the advantage that it can be used as is.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing the configuration of an embodiment of the present invention, FIG. 2 is a block diagram showing the configuration of the second floppy disk control circuit 6 in FIG. 1, and FIG. 3 is a high recording density recording medium. An explanatory diagram showing an example of the configuration of the format, Fig. 4 (a
), (b) is a circuit diagram showing an example of the configuration of the floppy disk device control signal switching circuit 14 in FIG. 1, FIG. 4(c) is a circuit diagram showing an example of the configuration of the selector in FIG. 4(b), FIG. 5 is a flowchart showing the flow of seek processing according to the present invention, FIG. 6 is a timing diagram of a signal indicating recording medium replacement, and FIG. 7 is a timing chart of a signal indicating recording medium replacement according to the present invention. A circuit diagram showing the control circuit,
Figure 8 shows the control circuit 9 of No. 13 showing the replacement of the recording medium.
9 is a block diagram showing the configuration of a conventional floppy disk control circuit, FIG. 10 is a block diagram showing the configuration of a high recording density floppy disk control circuit as a conventional technology, and FIG. 11 ( Figure 11 (a) is a block diagram showing the configuration of an electronic computer system using a conventional floppy disk device, and Fig. 11 (b) shows the configuration of an electronic computer system using a high recording density floppy disk device as a conventional technology. Block diagram, FIG. 11(c) is a block diagram showing the configuration of an electronic computer system using a multi-recording density floppy disk device as a conventional technology,
It is. Explanation of symbols 3...first floppy disk control circuit, 5...
Multiple recording density floppy disk device, 6... Second floppy disk control circuit, 8... Floppy disk control signal connection terminal, 9... Floppy disk device control signal control circuit, 12. ... Switching No. 13 generation circuit, 13... Switching signal, 14... Floppy disk device control signal switching circuit Agent Patent attorney Akio Namiki 112 Figure $1581

Claims (1)

[Scope of Claims] 1. A medium drive device capable of accepting and driving a medium recorded at any of a plurality of different recording densities and reproducing the same; When a first medium recorded at a first density among recording densities of
a second medium control circuit for controlling when a second medium recorded at a second density of the plurality of different recording densities is reproduced by the drive device; , a switching circuit that selectively connects the medium drive device to one of the first and second medium control circuits, and a CPU connected to each of the first and second control circuits via a bus. central processing unit);
When the first medium is loaded into the drive, the CP
U controls the drive device through the first medium control circuit, and when a second medium is loaded, the CPU controls the drive device through the second medium control circuit. In the drive device control system, when the medium loaded in the medium drive device is replaced with another medium, the second control system controls the drive device to output a medium change signal indicating the exchange of the loaded medium with another medium. Even if the CPU recognizes the medium change signal through the medium control circuit and resets the medium change signal as a result, the next time the CPU attempts to control the drive device through the first medium control circuit, the medium change signal will not be activated. A control system for a medium drive device using a CPU, characterized in that the first medium control circuit is provided with a medium change signal holding circuit that holds the signal without being reset. 2. A control system for a medium drive device using a CPU according to claim 1, wherein the first medium control circuit manages the track position of a head on a medium in the medium drive device; Each time a need arises, the media control circuit temporarily stores the current head position, then performs a seek to perform the desired processing, and after completing the processing, returns the head to the starting track position. A control system for a medium drive device using a CPU, characterized in that a control operation is performed.