JPS59136860A - Disk controller - Google Patents

Abstract

PURPOSE:To increase an address space which can be used to other programs by putting many secondary control programs on the same address and then selecting these programs in accordance with the disk attribute. CONSTITUTION:An attribute memory part 2 reads and stores the attribute of a disk. Based on the stored disk attribute, a control program selecting part 13 selects a secondary control program 4 in response to each disk. Then the writing and reading are carried out to the disk based on the selected program 4. Here the programs 4 corresponding to each disk attribute are put on the same address. In such a way, an address space which can be used to other programs is increased.

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial Field of Application 9) This invention relates to a control device for a floppy disk.

(Conventional structure and its problems) Conventionally, floppy disk drives have a single-density recording method (FM
), the number of recording bytes per sector was mainly 128 bytes, but in recent years not only FM but also double density recording (MFM) has been widely used, and Various recording length formats are used, including 128 bytes, 256 bytes, 512 bytes, and 1024 bytes. Therefore, when accessing two or more types of disks with different recording densities and recording lengths using a disk control device that supports each of the above formats, it is necessary to know in advance what format the disks to be accessed are recorded in, and to do so. It is necessary to perform access according to attributes.

A conventional disk control device will be explained with reference to FIGS. 1 and 2.

FIG. 1 shows a conventional disk control device, where 1 is an attribute storage section that stores the attributes of a file, 7 is an access control program section, 3 is an access control program (main control program) common to each attribute, and 4 is an access control program section common to each attribute. an access control program (sub-control program) corresponding to each attribute, 5 a recording density selection unit that selects the recording density when accessing the disk;
6 is each disk drive (hereinafter abbreviated as FDD).

The operation of the conventional disk control device configured as described above will be explained.

The disc has an index track, and the recording format of the index track is FM with 1 sector per sector.
It is uniformly specified as 8 bytes. Further, attributes such as the recording density and recording length of the disc are written on the index track 1, and by reading it, the attributes of the disc can be known. When accessing a disc, first set the recording density selection unit 5 to FM, and
The attributes of the disk are read from the index track in the format of 128 bytes per sector and stored in the attribute storage section 2. In subsequent accesses to the disks, accesses such as writing and reading are performed by the sub-control program 4 corresponding to each disk, depending on the stored disk attributes. Each sub-control program is FM, 1 sector for 128 bytes, FM, 1 sector for 256 bytes,
MFM for part-time work.

They are made to correspond to each disk format, such as 256 bytes per sector, MFM, 512 bytes per sector, etc. A conventional example of the access control program section 7 is shown in FIG. The access control program unit 7 consists of a main control program 3 that can be used in common even if the recording format of the disc changes, and a sub-control program 4 that corresponds to the recording format of each disc. There are often two or more types of sub-control programs 4. The sub-control program 4 includes a basic access control program 3 for the disk, such as a write program 8, a read program 9, a comparison program 10, and an initialization zologram 11. In the past, each side control program 4 was placed on a different address, so as the number of sub-control programs 4 increased, it became more difficult to accommodate more types of disk access. The problem is that the longer the program runs, the more address space is required, which reduces the address space available for other programs. Furthermore, when moving from the main control program 3 to the sub-control program 4, the address to be moved to differs depending on the attributes of each disk even when moving to the same writing program.

The same applies when moving from the main control program 3 to other programs such as the read program 9 and the comparison program 10.1. By this, the main control program 3
Another problem is that the processing when moving from the program to the sub-control program 4 becomes complicated.

(Object of the Invention) The present invention solves the problems of the disk control device described above, and by locating a large number of sub-control programs on the same address, the address space can be used for other programs. It is an object of the present invention to provide a disk control device that allows for the expansion of the main control program and the easy processing of moving from a main control program to a sub-control program.

(Structure of the Invention) The present invention includes an attribute storage unit that reads and stores attributes of recorded information on a disc, an access control program unit that has two or more types of access control programs according to the attributes of each disc, and an access control program unit that stores information in the attribute storage unit. a control program selection section that selects an access control program from the access control program section based on the attributes of each disk; and a control program selection section that selects an access control program corresponding to each small attribute from the access control program section; By locating the access control program at the same address, the address space available for other programs is expanded, and the main control program This allows the process of moving from the program to the sub-control program to be easily performed.

(Description of Embodiment) FIG. 3 shows an embodiment of the present invention, in which 1 is a host processing device;
2 is an attribute storage unit, 3 is a main control program common to each attribute, 4 is a sub-control program corresponding to each attribute located on the same address, 5 is a recording density selection unit, and 6 is an FD
It is D. 7 is an access control program section including a main control program 3 and two or more types of sub-control programs 4; 13 is a sub-control program section corresponding to each disk based on each attribute of the disk stored in the attribute storage section 2; This is a control program selection section that selects the program 4.

The operation of the disk control device of this embodiment configured as described above will be explained. The process up to reading and storing the disk attributes in the attribute storage section 2 is the same as a conventional disk control device. After the storage, when accessing the disk, the control program selection unit 13 selects the sub-control program 4 corresponding to each disk based on the stored disk attributes, and depending on the selected sub-control program, the control program selection unit 13 selects the sub-control program 4 for each disk. Write and read. As in this embodiment, sub-control programs 4 corresponding to the attributes of each disk are provided at the same address, and individual control programs such as a write program 8, a read program 9, a comparison program 10, an initial read program 11, etc. By providing these on the same address, the process of moving from the main control program 3 to the sub control program 4 can be performed in common for all attributes, making it easier to create the main control program 3. It is also possible to shorten the length of the program. Furthermore, unlike conventional disk control devices, the sub-control programs are not located in different address spaces, but are all located at the same address and are selected and used in the control program selection section 3 13. Even if the number of sub-control programs 4 is increased, the address space used for other programs will not be reduced.
Compared to the i-control device, more address space can be used for other programs.

(Effects of the Invention) The present invention positions the sub-control programs of the disk control device at the same address, and selects the sub-control program in the control program selection section according to the disk attributes stored in the attribute storage section. By using this, it is possible to handle many types of disk attributes with a small address space, and furthermore, moving from a main control program to a sub-control program is possible regardless of each attribute, as long as the program operates in the same way. Since all the data needs to be moved to the same address, the creation of the main control program is easy and short, making it possible to create an excellent disk control device that has the effect of freeing up a large amount of address space for use by other programs. be.

[Brief explanation of the drawing]

FIG. 1 is a block diagram and lock diagram of a conventional disk control device, and FIG. 4 is a diagram showing an example of the configuration of an access control program section according to the present embodiment. 1... Upper processing device, 2... Attribute storage unit, 3...
Main control program, 4... Sub-control program, 5...
・Recording density selection section, 6... Disk drive (FDD
), 7... access control program section, 8... writing program, 9... reading program, 10
...Comparison program, 11...Initialization program,
12... Floppy disk device, 13... Control program selection section.

Claims (1)

[Claims] In a disk control device that controls access such as writing and reading information to a disk by a host processing device, an attribute storage unit that reads and stores attributes of recorded information from the disk and an access control program corresponding to the attributes of each disk are the same. an access control program section having two or more types of addresses; and a control program selection section for selecting an access control program according to each attribute based on the attributes of each disk stored in the attribute storage section. and a recording density selection unit that selects a recording density when accessing a Dinuku according to each attribute.