JP2839729B2 - FDD control method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to an FD having different storage densities.
The present invention relates to an FDD control method suitable for use in a personal computer having an FDD (floppy disk drive) capable of accessing a (floppy disk).

[0002]

2. Description of the Related Art In recent years, with the advance of semiconductor technology, microprocessors, peripheral control LSIs, memory LSIs, etc. have been supplied at very low cost. You can now build. In addition, the development of input / output devices has been remarkable, and in particular, 3.5-inch floppy disk devices frequently used as external file devices of this kind have been increasing in density year by year. In parallel with this, some FDDs (floppy disk drives) have been developed which can handle a plurality of types of media with one unit.

[0005] By the way, a 3.5-inch FDD used as a standard in the field of this type of personal computer is:
It supports 2DD media with a storage capacity of 1 MB, 2HD media for overseas of 2MB, or 2HD media for 1.6MB for domestic use (hereinafter referred to as 2-mode FDD).

In order to access the above-mentioned 1 MB and 2 MB (1.6 MB) media, the rotation speed of the FDD motor is set to 300 rpm for overseas use and 36 rpm for domestic use.
The control was performed by switching the data transfer rate as a fixed rotation speed of 0 rpm. That is, the firmware does not perform any control on the number of motor revolutions, and executes access control on 2DD media and 2HD media by changing only the data transfer rate.

In order to perform this control, firmware
The data transfer rate currently set in the DC (floppy disk controller), the data transfer rate to be set in hardware by the next access to the first FDD, and the next access to the second FDD Thus, a flag for storing three pieces of information of the transfer rate to be set in the hardware is set in the work memory, and the control is performed using the flag as an internal flag.

[0006]

In the above-described conventional two-mode FDD, it is possible to control access to each medium only by switching the data transfer rate.
However, since the control of the motor rotation speed is not performed only by switching the data transfer rate, 2H recordings having different recording densities are not performed.
D media cannot be accessed.

The present invention has been made in view of the above circumstances. By adding a flag for controlling the number of rotations of the motor to the conventional two-mode FDD control flag, it is possible to access 2HD media having different recording densities. It is an object of the present invention to provide an FDD control method for realizing a so-called three-mode FDD control.

[0008]

SUMMARY OF THE INVENTION The present invention relates to a personal computer in which an FDD (floppy disk drive) supporting a plurality of media having different recording densities is connected to a main body CPU via an FDC (floppy disk controller). Means for setting parameters in the main body memory when first trying to access for the type determination, and setting the data transfer rate to start the trial in the main body built-in memory, and taking into account the motor rotation stabilization wait, Means for setting a parameter different from the above set value for an internal flag in which a parameter of the motor rotational speed set in the FDC is set, wherein the main body CPU accesses the specific sector in accordance with each of the above parameter settings. To check the validity of the access, and Wherein the retry determining the data transfer rate as well as the parameters of the motor speed should be tried next is Te.

[0009]

The three-mode FDD is an FDD that can access three types of 2HD media (1.6 MB / 2 MB) having different storage densities from 2DD media. 2-mode FD
In the case of D, the data transfer rate is changed by writing to the register, and access to different types of media has been realized. On the other hand, in the 3 mode FDD, in order to access 2HD media having different storage densities, the storage density is changed by switching the number of rotations of the FDD motor in addition to switching the data transfer rate, thereby realizing the access. At this time, the setting of the motor rotation speed to the hardware is executed by writing to the register in the same manner as the setting of the data transfer rate. As a result, the three-mode FD
D can be supported, and an inexpensive system can be constructed.

[0010]

Embodiments of the present invention will be described below in detail with reference to the drawings. FIG. 1 is a block diagram showing an embodiment of the present invention.

In the figure, reference numeral 1 denotes a main body CPU,
Be the control center of the system. 2 is BIOS-ROM
A program for controlling each input / output device connected to a system such as a floppy disk device is stored, and the main body CPU 1 reads out and executes the program.

Reference numeral 3 denotes a main memory in which an operating system (OS) and application programs are stored, and a free area is used as a working area. Flags and the like appearing in the following description are assigned to this area.

Reference numeral 4 denotes a floppy disk controller (referred to as FDC). This FDC4 is the main CPU
1 and the FDD, and performs format control independently of the main body CPU 1.

Reference numeral 5 denotes a floppy disk drive (F
DD), two drives are connected, and media having different recording densities of 2DD and 2HD are loaded in each of the drives. Hereinafter, this FDD is referred to as a three-mode FDD 5. Reference numeral 6 denotes a system bus to which the above-described control blocks 1, 2, 3, and 4 are commonly connected.

FIGS. 2 and 3 are diagrams cited for explaining the operation of the embodiment of the present invention. FIG. 2 is a diagram showing an access process for 2HD media (2 MB).
5 is a flowchart showing the operation of the embodiment of the present invention.

In FIG. 2, reference numeral 11 denotes a time wait, and the type of the FD is unknown due to the insertion of the medium, and the current motor speed is not known. Reference numeral 12 denotes a time area to be accessed, which is an access attempt using parameters at the time of 2DD media access.

Reference numeral 13 denotes waiting for time, and the next 2HD
(2 MB) Waiting for the motor rotation stabilization time, which is performed because the motor rotation speed at the time of access based on media parameters is different from that at the time of 2DD media access. Reference numeral 14 denotes an access time area, which is an access attempt using parameters at the time of 2HD (2 MB) access.

In FIG. 3, reference numeral 15 denotes a step for determining a trial start parameter. When the type of the FD is not known, a data transfer rate and a motor rotation speed when an access trial is first performed are determined.

Reference numeral 16 denotes a step of setting parameters in the hardware. The data transfer rate at the time of access and the motor rotation speed are set in the hardware W, and the motor rotation stabilization time when the motor rotation speed changes. Execute the wait.

Reference numeral 17 denotes a step for determining parameters for the next trial. When the access trial is not completed normally, the data transfer rate and the motor rotation speed for the next trial are determined. Hereinafter, the operation of the embodiment of the present invention will be described with reference to the drawings.

First, the general operation will be described. 3 mode FDD
Reference numeral 5 denotes an FDD capable of accessing three types of 2HD media (1.6 MB / 2 MB) having different storage densities from 2DD media. In the case of the two-mode FDD, the data transfer rate is changed by writing to a register, thereby realizing access to different types of media. On the other hand, in 3 mode FDD, 2HD with different storage density
In order to access the media, the storage density is changed by switching the number of rotations of the FDD motor in addition to switching the data transfer rate, thereby realizing the access. At this time, the setting of the motor rotation speed to the hardware is executed by writing to the register in the same manner as the setting of the data transfer rate.

A specific combination of the transfer rate and the motor speed at the time of media access is 300 Kbps / 360 rpm for 2DD media, and 2H for domestic use.
500 kbps / 360 rpm for D media,
500kbps / 3 for 2HD media for overseas
00 rpm. For this reason, in the access processing of the three-mode FDD, it is necessary to make the information regarding the motor rotation speed exist in the work memory 3 and control the access processing based on this information. As the information on the motor rotation speed, it is necessary to store the motor rotation speed set in the hardware at the time of the next access. Therefore, an internal flag for storing this information needs to exist in the work memory 3. . When changing the motor rotation speed of the three-mode FDD 5, after setting the motor rotation speed for the FDC 4, if the motor does not have a certain set time, the motor will not be stable at the specified rotation speed, Immediately after the switching of the number of revolutions, a state occurs in which the medium cannot be normally accessed. Therefore, when the motor speed is changed,
Since it is necessary to access the media after a motor rotation stabilization wait time until the rotation of the motor is stabilized, information on the current motor rotation speed is also stored in the work memory 3 so that the current hardware setting and When switching to a different rotation speed, wait for a motor rotation stabilization wait time. Hereinafter, the operation of the above embodiment will be described in detail.

FIG. 2 shows an example of the operation when a medium is inserted into the three-mode FDD 5 and the medium is accessed, and FIG. 3 is a flowchart showing the operation of accessing the medium by the three-mode FDD 5. Is as described above.

The main unit CPU 1 receives the FD from the previous access.
Type of media inserted in D5 (2DD, 2HD
If (1.6 MB) or 2HD (2 MB) is known, access is executed at the same transfer rate and motor rotation speed. However, new media FD
Since the type of the medium is not known when inserted into D5, the parameter for the first access attempt to determine the type of the medium is set in the internal flag (step 15 in FIG. 3).

At this time, since the number of rotations of the motor at the time of the next access is unknown, an internal flag storing information on the number of rotations of the motor currently set in the FDC 4 so that the motor rotation stabilization wait is reliably performed. , Rotation speed data different from the set value is stored. For this reason, after setting the data transfer rate and the motor rotation speed for the FDC 4 (step 16 in FIG. 3), it is determined that the motor rotation speed has been switched by the internal flag relating to the motor rotation speed, and the motor rotation stabilization time waiting process is performed. Step 11 of FIG. 2 performed.

Then, the medium is accessed (step 12 in FIG. 2). Here, when the access is performed with the correct parameters, the access to the medium is normally completed and the processing is completed by one trial. However, if the access is made with different parameters and the operation is abnormally terminated, the data transfer rate and the motor rotation speed to be tried next are set (step 17 in FIG. 3).

At this time, if the data transfer rate for the next trial is 500 kbps, if the FDD type is set to domestic (1.6 MB), the motor speed is 360 rpm, and overseas (2 MB) Is set to 300 rpm.

Then, the data transfer rate and the motor rotation speed are set again for the FDC 4. At this time, when the motor rotation speed is switched, it is necessary to wait for the motor rotation stabilization time again (FIG. 2). Step 13). After that, access to the medium is executed according to the parameter to be tried next (step 14 in FIG. 2).

[0029]

As described above, according to the present invention, it is possible to access 2HD media having different recording densities by adding a flag for controlling the motor rotation speed to the conventional 2 mode FDD control flag. Control of so-called three-mode FDD can be realized, and an inexpensive system can be constructed.

[Brief description of the drawings]

FIG. 1 is a block diagram showing the configuration of an embodiment according to the present invention.

FIG. 2H illustrates the operation of the embodiment shown in FIG. 1;
The figure which shows the access processing state with respect to D media (2MB).

FIG. 3 is a flowchart for explaining the operation of the embodiment shown in FIG. 1;

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Main body CPU, 2 ... BIOS-ROM, 3 ... Main memory,
4: Floppy disk controller (FDC), 5:
Floppy disk drive (FDD), 6 ... system bus.

Continuation of the front page (58) Field surveyed (Int.Cl. ⁶ , DB name) G06F 3/06

Claims (1)

(57) [Claims] An FDD (Floppy Disk Drive) supporting a plurality of media having different recording densities is an FD.
Main unit C via C (floppy disk controller)
In the personal computer connected to the PU, means for setting parameters for the first access attempt for determining the type of media in the main memory, and setting a data transfer rate at which the trial is to be started in the internal memory of the main unit. , And considering the rotation stabilization of the motor,
Means for setting a parameter different from the set value for the internal flag in which the parameter of the motor rotation speed set in the main CPU is set. The main body CPU accesses a specific sector in accordance with each of the parameter settings. FD which checks the validity of the access, determines the data transfer rate to be tried next and the parameters of the motor speed based on the result, and retry.
D control method.