JPH077326B2 - Flexible disk drive interface controller - Google Patents

Description

The present invention relates to an interface of a large-capacity external storage device, and more particularly to a flexible disk drive interface control device suitable for connection with a conventional flexible disk controller.

[Conventional technology]

A conventional host computer, such as personal computer 20, is
As shown in the figure, a flexible disk controller 21 is provided inside the flexible disk 22.
Is configured to be able to read and write data. Dedicated drive software 23 is applied to the flexible disk controller 21.

In the personal computer 20 having such a configuration, for example, a hard disk
When connecting the 24, the user purchased the hard disk controller 25 and the drive software 26 dedicated to the hard disk controller 25 and switched to the flexible disk controller 21 to connect to the personal computer 20.

As described above, in the conventional device, when connecting the personal computer and the storage medium other than the flexible disk, the flexible disk controller 21 and the drive software 23 therefor cannot be used at all, and the drive controller for the storage medium and the same Since dedicated drive software must be connected, the user's burden is heavy, and there is a problem in that a space for installing these must be prepared in the personal computer, and the personal computer becomes large.

In order to deal with such a problem, it has been proposed to provide a flexible disk drive interface control device between the flexible disk controller and a storage medium other than the flexible disk to connect them.

An example of this flexible disk drive interface control device is disclosed in JP-A-58-97103. In this publication, a comparatively small capacity storage medium such as a bubble memory or an IC memory is considered.

[Problems to be solved by the invention]

The prior art described above does not consider a large-capacity storage medium, and has a problem in processing when the storage capacity of one flexible disk (1 Mbyte in the case of an 8-inch double-sided double-density disk) is exceeded.

Further, the specific circuit of the flexible disk drive interface device is not disclosed, and there is a problem that this cannot be easily implemented.

The object of the present invention is to eliminate the above-mentioned problems of the prior art,
A flexible disk drive interface control device using a large-capacity storage medium that can be controlled as a conventional flexible disk drive without changing the hardware and software of the flexible disk controller of the host system.

[Means for solving problems]

In order to achieve the above object, the present invention provides an interface between a flexible disk drive interface section having a signal interface specification and a connector specification equivalent to a flexible disk drive and a large capacity external storage device for controlling a large capacity storage medium. In a flexible disk drive interface control device having a face and a flexible disk designating section, the flexible disk drive interface section is a format for a mass storage medium and a designated flexible disk format (8 inch, 5.25 inch, There are various types such as single density, double density, double track, number of sectors / track, number of bytes / sector, etc.).

[Action]

The flexible disk drive interface control device has a flexible disk drive interface section that operates in a hardware and software exactly equivalent to a conventional flexible disk drive in terms of hardware and software with respect to the flexible disk controller of the host system. Based on an instruction from the flexible disk controller, the large-capacity external storage device is controlled such as reading and writing. At that time, when considering the large-capacity storage medium as an equivalent flexible disk media aggregate in which a plurality of flexible disk media are gathered, the flexible disk media such as the corresponding flexible disk media number or the name of the corresponding flexible disk media. A specific physical address area (cylinder number, track number, sector number, etc.) to be read or written in the large-capacity storage medium in the large-capacity external storage device based on the instruction data from the flexible disk designating section for designating the identification means Physical position data). Therefore, by controlling the flexible disk controller, the host system can handle a large-capacity storage medium in exactly the same procedure as a conventional flexible disk drive, and the entire storable data area of the large-capacity storage medium can be handled. Can be used.

〔Example〕

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

FIG. 1 is a block diagram showing an embodiment of the present invention.
Flexible disk drive interface controller
1 (hereinafter, referred to as FDD / F controller) is a flexible disk controller 3 (hereinafter, referred to as FDC) of the host system 2.
Is called), the large-capacity external storage device 4 is controlled for reading and writing. that time,
The physical address area of the mass storage medium is determined based on the instruction data from the flexible disk designating unit 5 (hereinafter referred to as FD designating unit).

An optical disc is assumed here as a large-capacity storage medium. The FDI / F control device 1 includes a microprocessor unit (MPU) 6, an optical disk controller (ODC) 7 for controlling a large-capacity external storage device (optical disk drive) 4, a flexible disk drive interface unit 8 (hereinafter, FDI / F unit). Called), buffer memory (RAM) 9, FDDI /
It comprises a fixed memory (ROM) 10 in which software for controlling the F controller 1 is stored, and the FD designating section 5.

The buffer memory 9 is provided to absorb the difference between the data transfer rate of the FDC 3 and the data transfer rate of the optical controller 7. If the data transfer rates of the two are exactly the same, it is basically unnecessary. is there.

The fixed memory (ROM) 10 is also basically unnecessary if the MPU 6 is a one-chip type (I / O, ROM, RAM are built in the MPU).

The FD designating section 5 can be designated by the ten keys (0 to 9) if the number of the flexible disk medium is designated. If the name of the flexible disk medium is used, it can be input using a normal character keyboard. From this FD designating part 5, the host system 2
It is also possible to specify the type of flexible media handled by FDC3 (8 inch, 5.25 inch; single density, double density, double track; sector number / track; byte number / sector, etc.).

In addition, the hardware and software of the host system 2 are modified to incorporate the FD designating unit 5 into the host system 2, and the data such as the number, name, and type of the corresponding flexible disk medium are directly input to the MPU 6 of the FDC I / F controller 1. May be transmitted.

FIG. 2 is a circuit diagram showing a specific example of the main part of the FDC I / F unit 8.

First Flexible Disk Controller (FDCI) 11
Is used as a format-only FDC, and the second flexible disk controller (FDCII) 12 is used as a read / write-only FDC. Here, an existing FDC (for example, FDC μPD 765A manufactured by NEC Corporation) is used.

Next, the write clock signal (WCLK signal) and the window signal (WINDOW signal) input to the two FDCs 11 and 12 will be described with reference to FIG.

The WCLK signal is a carry output signal t of a counter (eg, TTL IC 74 LS 161) 13 that counts the 8 MHz clock p.
To use. The counter 13 has count input terminals A, B, C set to 0 and D set to 1, so that the initial value is 8.
When the clock p is input, it is counted as 9, 10, 11, 12, 13, 14, and when the next clock p is input and becomes 15, the carry output signal t is output. The carry output signal t is input to the load terminal via the inverter 14. As a result, the counter 13 returns to the initial value 8 again.

The counter 13 counts the 8 MHz clock p and outputs the count value as Q _A (q), Q _B (r), Q _C (s), and Q _D. Since the count value (initial value) set in the counter 13 is 8 (because the count input terminals A, B, C are 0 and D is 1) from Q _D , 1 is always output. The carry signal t is output when Q _A , Q _B , Q _C and Q _D are all 1. Therefore, the carry output signal t is generated at a repetition frequency of 1 MH.

This WCLK signal is a signal that becomes a clock signal and a data signal of a bit serial data train (pulse train) in the case of modulation in the MFM mode.

The window signal is a signal that separates the bit serial data train (pulse train) into a clock signal component and a data signal component. The D latch (eg, TTL IC 74 LS 74) 15 divides the Q _C signal by half. Has been generated. For the window signal, read data (RDAT
It can also be generated from the VFO circuit (variable frequency oscillation circuit) 16 using the A) signal. When synchronization with the write clock signal of the flexible disk controller 3 of the host system 2 cannot be achieved, it is better to use the window signal created by the VFO circuit 16.

Next, at the time of reading data from the large-capacity external storage device 4 or writing data to the storage device 4,
The operation of FDC I 11 will be described with reference to FIGS. 2 and 4.

The index signal (INDEX signal) input to the FDCs 11 and 12 shown in FIG. 2 is a signal generated once per revolution of the flexible disk drive. What is the rotation speed of the drive of the mass storage device 4? However, there is a trade-off with the track format, and it is difficult to make them perfectly match. Therefore, here, the index signal is generated by software (internal timer of MPU6).

The first FDC I 11 is a format-dedicated FDC, and its data pattern output signal (WDATA signal) c is controlled by the MPU 6 according to the track format pattern k of the flexible disk 7 (see FIG. 4) and the INDEX signal (I
It is output in synchronization with D).

Write enable signal (WE) output from the first FDC 11
b is a signal indicating whether the WDATA signal c is valid, SYN
The C signal d is a signal indicating the timing of reading data. FDC I 11 is a format-only FDC, so flexible disk media track format k
The WDATA signal c is output with a data pattern according to the above.

Next, the read and write operations of this embodiment will be described.

(1) Read operation (when the host system 2 reads data from the large-capacity external storage device 4) First, the data of the large-capacity external storage device 4 is read by the optical disk controller 7 based on the specified data input from the FD specifying unit 5. It is assumed that a predetermined amount is read and stored in the RAM 9. During the read operation, the data is transferred from the RAM 9 to the FDD I / F unit 8 through the data bus.

Now, during the read operation, the data flow is FDD I /
Since it goes from the F section 8 to the host system 2, the second FDC II
12 is in the write mode for the host system.
When using the second FDC II 12 as a write mode,
As the data pattern to be output, the ID data is read in synchronization with the SYNC signal g in accordance with the track format k, and the data (WDATA signal) f is written together with the synchronization signal (SYN) in the sector of the matched ID data.

The WDATA signals f and c are switched by the first selection circuit (first multiplexer) 17 according to the WE signal e of the second FDC II 12 and output to the host system 2 as read data (READ DATA). It

The READ DATA sent to the host system 2 is the first FDC I
The hatched area of WDATAc of 11 is C II of 2nd F
The data string is replaced with WDATAf.

Therefore, according to this embodiment, the FDD I / F control device 1 can read the data of the large capacity external storage device 4 in the same data format as the flexible disk drive.

(2) Write operation (when the host system 2 writes data to the large-capacity external storage device 4) Since the data flow goes from the host system 2 to the FDD I / F control device 1, the second FDC II 12 The read mode is set for the host system 2.

Using the second FDC II 12 as read mode,
As for the data pattern to be input, first, the ID data therein is read in synchronization with the SYNC signal j according to the track format k. Then, the data (RDATA signal) transmitted following the sector of the matched ID data is read together with the synchronization signal (SYN). The RDATA signal is a data signal switched by the second selection circuit (second multiplex) 18 according to the WRITE ENABLE signal output from the FDC 3 of the host system, and is the WD of the first FDC I 11.
The ATAc hatching area is the WRIT from the host system 2.
The data string is replaced with E DATA.

The data string is separated into a clock signal component and a data signal component by the window signal in the second FDC II 12, and the data signal component is temporarily stored in the RAM 9 through the data bus. Then, the data signal component is
It is stored in a predetermined physical address area of the mass storage device 4.

In other words, the WDATAc remains unchanged from the host system 2.
Since it is output to FDC II 12, according to this embodiment, the same data format as the flexible disk drive can be converted to FDC without any format conversion.
By inputting to the I / F control device 1, data can be written to the large capacity external storage device 4.

According to this embodiment, as is clear from the above description, the FD
The I / F control device 1 converts the data read from the same large-capacity storage medium into a flexible disk track format that can be controlled by the FDC 3, according to the contents of the FD designating unit 5, the buffer RAM 7, and the fixed memory ROM 10. Then, it can be provided to the host system 2. In that case, the buffer
It is desirable that the RAM can store data for one track.

The signal bus between this capacity external storage device and the FD I / F controller is a standardized signal bus (GPIB, ST506, ESDI,
It is self-evident that more versatility is achieved by using SCSI, VME, multi-bus, etc.).

〔The invention's effect〕

According to the present invention, various excellent effects as described below can be expected.

(1) The FDD I / F controller uses a large-capacity external storage device.
It can be operated exactly equivalent to a conventional flexible disk drive, and moreover, the FD designating section can designate an arbitrary position (physical address) of the mass storage medium as a data area of the flexible disk medium.

(2) By using two existing FDCs, one of them as a format-only FDC and the other one as a read or write-only FDC, the compatibility with the FDC of the host system is improved, and the FDC I The hardware and software load of the / F controller is reduced.

(3) The same mass storage medium can be provided to the host system as a flexible disk of any track format depending on the contents of the software of the FDC I / F control device.

(4) The entire data area of the mass storage medium can be provided to the host system as a plurality of flexible disk media.

[Brief description of drawings]

FIG. 1 is a block diagram showing an embodiment of the present invention, FIG. 2 is a circuit diagram showing a concrete example of the main part of a flexible disk drive interface portion, and FIG. 3 is a diagram showing the write clock signal of FIG. FIG. 4 is a timing chart showing a window signal generation procedure, FIG. 4 is a timing chart for explaining the read and write operations of FIG. 2, and FIG. 5 is a block diagram when a hard disk device is added to a conventional host computer. . 1 ... Flexible disk drive interface controller 2 ... Host system 3 ... Flexible disk controller 4 ... Large-capacity external storage device 5 ... Flexible disk designator 6 ... Microprocessor unit 7 ... Optical disk controller 8 ... Flexible disk drive interface 9 Buffer memory 10 Fixed memory 11 First flexible disk controller 12 Second flexible disk controller 16 VFO circuit 17 First selection circuit 18 ... Second selection circuit

Claims (3)

[Claims] 1. A flexible disk drive interface unit and an interface with a large-capacity external storage device,
In a flexible disk drive interface control device including a flexible disk designating section, the flexible disk drive interface section formats the large-capacity external storage device and the flexible disk media format designated by the flexible disk designating section. And the flexible disk designating unit identifies the plurality of flexible media when the large capacity storage medium of the large capacity external storage device is equivalently regarded as a plurality of flexible disk media. A flexible disk drive interface device, characterized in that means (number, name, media format, etc.) can be input to specify an arbitrary area of the mass storage medium. 2. The flexible disk according to claim 1, wherein the external specifications of the flexible disk interface section have signal interface specifications and connector specifications equivalent to those of an actual flexible disk drive. Drive interface control device. 3. The flexible disk drive interface section has two existing flexible disk controllers (FDC), one of which is a dedicated FDC for flexible disk format and the other one is a dedicated FDC for reading or writing data. The flexible disk drive interface control device according to claim 1, wherein the flexible disk drive interface control device is used as a device.