JPS588066B2 - floppy disk storage device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a floppy disk storage device that can stably drive floppy disks regardless of the type of removable storage medium (hereinafter abbreviated as diskette).

The most commonly used floppy disk storage device has a soft sector diskette.

Figure 1 shows a hard sector type diskette, where 11 is a disk medium, 12 is a disk medium, and 12 is, for example, 32 disks on the same circumference.
The sector holes 13 arranged in equal parts are only one index hole provided between certain adjacent sector holes 12.

Note that the soft sector type diskette has only the index hole 13 shown in FIG. 1 and does not have the other holes 12.

The drive device optically detects and processes the sector holes and index holes described above.

The hard sector type drive device has a physical sector/index separation circuit, and based on the fact that the index hole exists in the middle of the pitch of the evenly arranged sector holes, the index is located at the origin of the diskette rotation angle in the timing window. It gives

When a soft sector type diskette is installed in a drive device of this type, an index output signal is not generated, but a signal corresponding to the index is generated at the sector signal output terminal, and single sharing is impossible.

Also, since soft sector drive devices assume diskettes with only index holes,
Hard sector diskettes with isolation circuits such as those described above cannot be used.

An object of the present invention is to eliminate such drawbacks and provide an apparatus that can share a soft sector type diskette and a hard sector type diskette.Examples thereof will be described below.

Figure 2 shows the index sector detection logic circuit of a floppy disk storage device.
is a retriggerable monostable multibibreak that is triggered by a negative transition on the T terminal signal, producing a positive pulse on Q.

Q outputs the inverted signal.

AG1 to AG4 are AND gates, and RG1 is an OR gate.

HIS is the photoelectric detection power signal, (2)NX is the index signal output, and SEC is the physical sector signal output, and these also serve as the names of the respective output terminals.

G1 and G2 are each monostable multi-bibreak MML
The output signals G1 and G2 of MM2 are signals with opposite phases.

HS is the output signal of gate AG1.

The relationships among these signals are shown in FIGS. 3 and 4.

Also, monostable multi-bibreak MM1, gate AG1,
Part A consisting of AG2 has the function of separating a physical index signal and a physical sector signal from a HIS signal obtained from a hard sector type diskette as shown in FIG.

Next, the operation will be explained.

FIG. 3 shows the operation of the circuit of FIG. 2 when a hard sector diskette is used.

As shown, the pulse width TG1 of the monostable multivibrator MM1 is triggered by the green signal after the signal HIS, and Ts/2<
TG1<Ts-Tw relationship is satisfied.

However, T8 is the period of the HIS signal, and Tw is the pulse width of the signal HIS.

As a result, only the physical index signal can pass through gate AG2, and this signal passes through gate RG1.
Output to INX terminal.

Further, the physical index signal does not pass through gate AG1, and the index signal and sector signal are separated.

The monostable multivibrator MM2 is circuit B for determining the diskette type (soft sector type or hard type), and as shown in Figure 3, the pulse width TO2 of the monostable multivibrator MM2 is selected to be larger than Ts. As long as a hard-sector diskette is installed, the monostable multivibreak MM
2 is retriggered and the signal G2 is held high so that the isolated sector signal HS is connected to the gate AG4.
It passes through and is output to the SEC terminal.

FIG. 4 shows operating waveforms when a soft sector type diskette is installed.

In this case, the signal HIS contains only an index signal and its repetition period is much longer than Ts.

Therefore, no signal passes through gate AG2, and signal H
All IS passes through AG1.

In this case, the signal HIS passes through the gate AG3, so it is output to the INX terminal via the gate RG1, and is output as an index signal.

Also, there is no output at the SEC terminal.

As is clear from the above embodiments, according to the present invention, one device can be used for both hard sector and soft sector diskettes.

In addition, since it is possible to know which format of diskette is installed depending on the presence or absence of the SEC signal, not only is there no inconvenience in operation, but this can also be used to differentiate diskette formats depending on the purpose of the disk file. This makes it possible to use a new method such as using the SEC signal as the identification signal, which is advantageous in practice.

[Brief explanation of drawings]

FIG. 1 is a schematic configuration diagram of a hard sector type floppy disk storage medium (diskette), FIG. 2 is a wiring diagram of the main parts of a floppy disk drive device according to an embodiment of the present invention, and FIG. 3 is a hard sector type floppy disk storage medium (diskette). Figure 4 is a signal waveform diagram explaining the operation when a sector type diskette is installed.
FIG. 4 is a signal waveform diagram illustrating the operation when a sector type diskette is installed. A...Signal separation circuit, B...Discrimination circuit, AG, 3, AG4...AND gate.

Claims (1)

[Scope of Claims] 1. A circuit that takes as input a detection signal based on a hole provided in a hard sector diskette or a soft sector diskette and separates a physical sector and a physical index signal, and takes as input the detection signal. A floppy disk storage device comprising a circuit for determining a diskette format, and a logic circuit for determining an index and a sector signal in the detection signal from the outputs of both circuits. 2 The diskette type determination circuit is configured using a multi-by-break circuit having a predetermined time constant, and only in the case of hard sector type diskettes, the required index is determined by obtaining a continuous logic level 1 (or O) signal. 2. A floppy disk storage device according to claim 1, wherein the floppy disk storage device is capable of outputting sector signals.