JPS60217560A - Disk device - Google Patents

Abstract

PURPOSE:To control a data write command signal with flag data which indicates whether data corresponding to each data track number is allowed to be written or not by storing the flag data in a storage means and outputting the data according to the number of the track where a head is positioned. CONSTITUTION:The flag data FD which indicates whether writing is allowed or not as to every data track is stored in the ROM16 of a protecting means 14. A positioning means 12 generates a signal to position the head on a track #0. The head is positioned on the target track through a head control means 13 with a step signal SC, direction signal DC, and side select signal SS from the means 12. Simultaneously, the signals SC and DC are inputted to a counter 15 and the address signal of the track is inputted to the ROM16 to output the FD, which is inputted to the means 13 through an AND circuit 17 to write data on the target track with a write command signal W.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field of the Invention] The present invention relates to a disk device, and more particularly to a disk device having a function of determining whether or not data can be written to each data track.

[Prior art]

Generally, a disk device uses a disk as a recording medium,
a write/read head that is positioned on a predetermined data track of the disk based on a positioning signal output from a positioning control means; and a data write that instructs writing of data to the data track via the read/write head. and data reading means for instructing reading of data from the data track via the write/read data track.

However, in a conventional disk device configured as described above, an attempt is made to write data over a data track on which data has already been written, and the contents of the already stored data may be destroyed.

For this reason, it is known to affix an aluminum foil sticker 2 to the disk 1 to prevent writing, as shown in FIG. However, when attaching the aluminum foil sticker 2 to the disk 1 to prevent writing as in the first conventional technique, even if it is preferable to prohibit writing to all data tracks, it is possible to Not only is it not possible to prohibit writing only to the data trunk, but if a data track for writing and a data track for reading coexist, even the data track for reading can be prohibited from being read by the aluminum foil seal 2. In order to be
There is a drawback that data cannot be read.

Therefore, as shown in FIG. 2, there is also known a system that prohibits writing only to arbitrary data trunks. In the case of this second prior art, the data processing device 3 uses WRIT, which means that writing is prohibited on the disk device 4.
By outputting the E PROTECT signal WP, writing of data to the disk is prohibited. Here, the WRITE PROTECT signal wp is generated within the data processing device 3 by a microprogram or hardware. In addition, the WRI TEPRO
The TECT signal wp can also be applied directly to the disk device 4 from an external source other than the data processing device 3 via an external switch.

However, in the case of this second prior art, each time the disk device is started, the write/read head is moved, and the trunk number where the head is located is changed, the data processing device 3 side Processing on the data processing device 3 side is necessary because the program or hardware needs to check the destination trunk number, determine whether data can be written to the data track, and control the WRITE PROTECT signal wp accordingly. The disadvantage is that it becomes complicated. In addition, if a malfunction occurs in the processing flow on the data processing device 3 side, WRITE P
The ROTECT signal WP may not be properly transmitted to the disk device 4, and as a result, data already written on the disk may be destroyed.

[Summary of the invention]

The present invention has been made in view of the drawbacks of the above-mentioned prior art.Flag data indicating whether data can be written to each data track number is stored in a storage means, and on the other hand,
By configuring the flag data to be output in accordance with the number of the data track on which the head is located, the data write command signal is controlled by the flag data.

〔Example〕

Embodiments of the present invention will be described below with reference to FIGS. 3 to 5. Note that in the following description, the head will be described as being used only for writing.

In the figure, reference numeral 11 denotes data writing means, and the data writing means 11 outputs a write command signal W indicating execution of writing and a data signal representing the content to be written.

Further, 12 is a positioning control means for controlling the positioning of the head, and the positioning control means 12 specifies whether the target data trunk to be written by the head is on the front side or the back side of the disk 511)E 5ELE'C
A function to output a T signal ss, and a DIRE function that specifies whether the target data trunk exists inside or outside of the disk in the radial direction from the current position of the head.
It has a function of outputting a CT-1ON signal DC and a function of outputting a 5TEF' signal sc that commands head movement. Said 5IDE 5ELECT signal ss! :DI
A positioning signal is formed by the RECTION signal DC and the 5TEP signal 3C.

13 moves the head to the target data trunk,
and head control means for controlling the head to write data to the data trunk.

Here, the head control means 13 receives the 5TEP signal SC from the positioning control means 12 and the DI-RECTI signal SC.
The ON signal DC and the 5IDE 5E-LECT signal SS are inputted, and the data signal to be written is inputted from the data writing section 11, and the protection means 14
The write command signal W is input to the head, and the head is controlled to execute writing.

The protection means 14 is 5TE of the positioning control means 12.
P signal SC, IRECTION signal DC and 5IDE
5ELECT signal SS is inputted, and a write command signal W from the data writing section 11 is also inputted.

Here, the protection means 14 is composed of a counter 15, a ROM 16 as a storage means, and an AND circuit 17 as a write control means, as shown in FIG.

The counter 15 receives the 5TEP signals SC and D.
I RECTION signal DC is input, and the 5TEP
By counting the signal SC, the target data track on which the head is to be positioned, that is, the data trunk number, is detected, and the result is output as a 7-bit signal A. The count 15 is the same as the above 5.
Each time the TEP signal SC is counted, the D I REC
In response to the T I ON signal DC, the count value is amplified by 1 or counted down by 1, but if the count value is 0, it does not count down, and if the count value is, for example, 76, it does not count up. It has become. Thus, the counter 15 constitutes a track position detecting means.

Further, the 7-bit signals A and 5 are stored in the ROM 16.
An address signal that specifies the location of a target data track is input, which is an IDE 5 ELECT signal SS. On the other hand, the ROM 16 stores in advance flag data consisting of signals rlJ and rOJ indicating whether or not writing is possible for each data trunk number, and the signal "
1".

When the address signal is input, "0" is output as flag data FD in accordance with the target data trunk number specified by the address signal. Here, "1" indicates that writing is possible, and "0"
indicates that writing is not possible.

Further, the data write command signal W and the flag data FD are input to the AND circuit 17.

The disk device according to this embodiment is configured as described above, and its operation will be explained next.

First, flag data FD indicating whether or not writing is possible for each data track is stored in the ROM 16 of the protection means (step S1).

Next, the disk device is activated (step S2).

Then, the positioning control means 12 outputs the 5TEP signals SC and D.
I RECTION signal DC and 5IDESELECT
Initialization processing is performed in which the signal SS is appropriately activated and the head is positioned at the 0th track. As a result, O is automatically set in the counter 15.

Next, the positioning control means 12 outputs the 5TEP signal SC corresponding to the target data track and the DI RECT signal SC.
In order to output the ION signal DC and the 5IDESE-LECT signal SS, the head is controlled by the head control means 13 and positioned at the target data track (step S3).

Along with this, the 5TEP signal sc and DI REC-
The T I ON signal DC is input to the count 15, and the address signal specifying the position of the target data track is input to the ROM 16, so the ROM 16 outputs flag data FD for the data track number corresponding to the address signal. do.

Here, if the flag data FD is rlJ (step S4), the write command signal W is directly outputted to the head control means 13 via the AND circuit 17, so that the head control means 13 receives the write command. The signal W can also be used to control the plow head to write data to the target data track (step 35).

On the other hand, if the flag data FD is rOJ (step S4), the write command signal W is output from the AND circuit 1.
7, therefore, it is not input to the head control unit 13, and data writing is not executed (step 6).

〔Effect of the invention〕

As explained above, according to the present invention, flag data indicating whether or not data can be written to each data track number of the disk is stored in the storage means, and the flag data is stored in the storage means according to the number of the data track where the head is located. Therefore, every time the target data trunk to which data is to be written is changed, the microprogram or hardware on the data processing device side checks the destination trunk number and outputs the data. The process of determining whether writing is possible is omitted. This not only simplifies the processing on the data processing device side, but also ensures that even if a malfunction occurs in the processing on the data processing device side, the data has already been written.
The situation where the existing data is destroyed is avoided.

[Brief explanation of the drawing]

1 and 2 show a disk device according to the prior art, FIG. 3 is a block diagram of a disk device according to the present invention, FIG. 4 is a block diagram detailing a part of FIG. 3, and FIG. The figure is a flow diagram showing the operation of the present invention. DESCRIPTION OF SYMBOLS 11... Data writing means, 12... Positioning control means, 14... Protection means, 15... Counter, 16
...ROM, 17...AND circuit (double write control means). In addition, in the figures, the same reference numerals are used for the same or equivalent parts. Figure 1 Figure 2 Figure 3 Di4W Procedural amendment (M4 1, Indication of the case Patent application No. 59-Q72164 2, Name of the invention Disk device 3, Person making the amendment Representative Hitoshi Katayama Department 4 Agent 5 , Column 6 for detailed explanation of the invention subject to amendment, Contents of amendment (1) rROM16J on page 7, line 6 of the specification is rl
Correct with x8 bit ROM1 6J. (2) Insert the following sentence after "(Step 6)" on page 10, line 13 of the specification. After taking the logical product with W, the write command signal W is transmitted to the head control means 13, but if the device has a special write prohibition signal, the flag data FD cannot be directly input manually to this write prohibition signal. Also, the ROM 16 is used to store information regarding whether writing is permitted or prohibited for the target track.
However, a RAM may also be used, or a jumper wire corresponding to each write-protection trunk may be connected to a power supply, and the voltage supplied from the power supply may be used as a write-protection signal, or an equivalent method may be used. It may be a combinational circuit having the following functions. Furthermore, flag data FD is set for each trunk, but if multiple trunks are combined into one block,
The flag data FD may be set for each block. ``That's all.'' Showa year, month, day 2, name of the invention, disk device 3, person making the amendment) 5. Column for detailed description of the invention to be amended. 6. Contents of the amendment (1) In the 19th line of page 6 of the specification, the phrase "may be executed" is amended to read "may be executed."that's all

Claims (1)

[Claims] A disk comprising a head that is positioned on a predetermined data track of the disk based on a positioning signal constituted by a positioning control means, and a data writing means that commands writing of data to the data trunk via the head. In the apparatus, a storage means for storing flag data indicating whether or not data can be written corresponding to each data track number and outputting the flag data for each data track number at which a head is positioned; 1. A disk device comprising: write control means for controlling a data write command signal output from the data write means to instruct whether or not to write data based on flag data output from the data write means.