JPS62177619A - Interface device for connection of floppy disk - Google Patents

Abstract

PURPOSE:To attain connection even with the floppy disk FD device of different sizes by adding the drivers and buffers which undergo the wired OR connection to use them in place of the interface of the FD device to be connected externally. CONSTITUTION:When a request of connection is designated for an external FD by the signal (k) obtained by a switch, the selection signal is supplied to an FD driver #1 or #2 incorporated into a system by a driver selecting circuit 27. Then the outputs of the selection of a driver, the ON/OFF of a motor, etc. are inhibited. While the output of a buffer 22 is disabled and the output of a driver 24 is also inhibited. If the selection signal is supplied to the FD driver #2, for example, the signal sent from the driver #2 is turned into the signal (n) via a receiver 30 and supplied to an FD control circuit 26. The output is given to the external FD device through drivers 33 and 34. Then the driver selection signal and the motor ON/OFF signal are delivered to (j) via the driver 34.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field of the Invention] The present invention relates to a floppy disk connection interface device that allows a floppy disk device to be connected without having a dedicated connection interface in a system.

[Technical background of the invention and its problems]

Relatively small information processing devices such as personal computers and word processors use floppy disks as external storage. There are 8-inch, 5-inch, and 3.5-inch floppy disks.

By the way, 3.5 inch floppy disk drive (
There is a demand for converting between 5-inch media and 3.5-inch media in a global computer that has one or two built-in media. In this case, either an external floppy disk drive connection interface is provided in the system or another conversion device is used.

However, the former does not have a dedicated interface for connecting a floppy disk drive.
System cost l? This method is unfavorable in terms of performance, and the latter requires a conversion device, making it cumbersome to handle.

[Purpose of the invention]

The present invention has been made in view of the above circumstances, and has three, five
When converting (copying, etc.) between inch and 5-inch floppy disk media (8-inch is also possible), it is possible to easily connect to an external floppy disk device without having a dedicated interface for external floppy disk connection within the system. The purpose of the present invention is to provide a floppy disk connection interface device.

[Summary of the invention]

In order to achieve the above object, the present invention uses, for example, a printer interface, adds drivers/buffers that are wired OR connected to each of data, command, and status lines that serve as a connection interface with the main body, and connects a switch or a command. It controls the output of the driver/buffer in accordance with the connection mode designation (external floppy disk connection request) instructed by , and serves as an interface for an externally connected floppy disk device. This makes it possible to connect an external floppy disk without having a dedicated connection interface, and since floppy disk drives of different sizes can also be connected, copying between media of different sizes becomes easy.

[Embodiments of the invention]

Embodiments of the present invention will be described in detail below using the drawings. FIG. 1 is a block diagram showing an embodiment of the present invention. In order to actually employ this embodiment in a system such as a personal computer, a CPU (microprocessor), memory, and a control circuit group such as its input/output are required, but these components are not directly related to the gist of the present invention. It is omitted in the figure.

In the figure, 1 is a printer control circuit. In the embodiment of the present invention, this is a group of circuits that control the generally known Centro interface, and generates data and commands to be printed to the printer 7, and performs status checks. 2 is a pair of 3.5-inch floppy disk drives 12, 13.2 installed in the system. Alternatively, it is a floppy disk control circuit composed of a group of circuits that control an externally connected floppy disk drive 8.

Reference numeral 3 designates a bidirectional driver that serves as a data buffer output when a printer is connected, or a receiving buffer group for various status signals obtained from the external floppy disk drive 8 when connected. 4. When connecting a printer,
This is a driver to which commands issued from the system are sent to the printer 7, or a group of floppy disk drive sending signals is propagated when the floppy disk drive 8 is connected, and these are wired OR connected. A driver/receiver 5 serves as a printer status reception buffer when the printer 7 is connected, and serves as a sending driver for the floppy disk 8 when the floppy disk drive 8 is connected. 6 is a 25-pole D-sub connector for cable connection conforming to the Centro interface.

7 is a printer equipped with the above-mentioned Centro interface, 8 is a 5-inch floppy disk Kenfu 1-LJ+
It is a floppy disk device with a built-in J-4 song. Reference numeral 9 denotes an input/output cable for connecting a printer 7 or a floppy disk device 8 to the system, and a conventional printer cable can be used as is.

10 is the interface for the floppy disk drives 12 and 13 built into the system, and 1 is the connector. There are two connection methods, radial or daisy, both of which can be used. Note that 14 is a switch, which switches the connection of the Zolinta interface built into the system to either the printer device 7 or the external floppy disk device 8.

FIG. 2 is a block diagram showing FIG. 1 in more detail.

In particular, the internal structure of the system bead shown in FIG. 1 (within the broken line in FIG. 1) is shown. In the figure, 21 is a decoder that decodes various commands to be printed to the printer 7;
2 is a buffer for latching and outputting printer print data. Further, 23 is a de-11 printer 7hekoman r external output eggplant command◆ register, and 24 is a driver for outputting the command. 25 is a buffer for reading the status of the printer 7; Reference numeral 26 denotes a floppy disk control circuit that performs READ/ITE of data in the system and the external floppy disk device 8, and 27 a drive that performs switching control with the corresponding floppy disk drive (drive NO.) when the external floppy disk device 8 is connected. This is a selection circuit. 28 and 29 are signal output drivers to the floppy disk drives 12 and 13 built into the system, and 30 is a receiver for read data and other status signals output from the floppy disk drives 12 and 13. 31 is a conventionally well-known VFO circuit that separates read data into data and window signals.

32, 33, and 34 are a group of components added according to the present invention, and are a group of circuits used when the external floppy disk device 8 is connected. 32 is a signal receiving buffer from the externally connected floppy disk device 8, and its output is sent to the system built-in floppy disk drive 1.
The input signals of 2 and 13 are wired-ORed. 33
・34 is a driver that outputs to the floppy disk device 8. Reference numeral 35 denotes an inverting element, a so-called inverter, used when performing enable/demosol control to connect the external floppy disk device 8 to the system.

In the figure, A and B are connectors for the floppy disk drives 12 and 13 built into the system, and C
is a printer connection connector that complies with the Centro interface. Further, ① to ② are signal lines through which various signals are propagated, and each of them is explained in the operation description section.

The operation will be explained below. First, if a printer 7 compliant with the Centro interface is connected externally,
The printer connection mode is designated by signal K. C
When performing printer printing from the PU (not shown),
An operation designation is given to the pre/post control circuit 1 via the data bus (2), address bus (2), and read/write command (2).

The status of the cipher is read through the driver/receiver 5 by the signal ■, confirming that printing to the printer is possible, and then the print data is sent to the printer print data register (Fig. 2) and the offer 22) by the signal ■. set. Then, a print command is set in the command register 3 in response to the signal (2), and outputted to the printer 7 via the driver 4. Next, the signal printer status is checked via the driver/receiver 5. If the printer status (for example, printer, error, vapor end, printer select signal, etc. is included, and the details of this status are omitted as they comply with the Centro interface) are not abnormal, any printing was performed successfully. Show that.

Next, the operation of the two 3.5-inch floppy disk drives 12 and 13 built into the system will be explained. A READ or WRITE instruction is given to the floppy disk control circuit 2 by issuing respective signals, read/write signals, etc. from the CPU via the data bus (2) and the address (2). The signal is a floppy disk motor 0N10FF, )' live select signal, and a selection signal (for example, drive select and motor 0N10FF, etc.) to the drive FDD specified by the drive selection circuit 27 is output via the driver 28. The signal e sent to other floppy disk drives (12
or 13) control signals (e.g. write data).

(write gate, direction, step, etc.) are propagated and sent to the floppy disk drive (12 or 13) via the driver 29. Various signals (for example, read data, index, ready, write protect, etc.) sent from the floppy disk drive (12 or 13) are sent to the receiver 30.
The signal is input to the disk control circuit 26 via the controller.

The read data is separated into data and window signals by the VFO circuit 31 and input to the floppy disk control circuit 26.

It is assumed that the floppy disk connection connector 1 is connected to the floppy disk connector 1, except for the signal connection.

The operation of connecting an external floppy disk, which is a feature of the invention, will be explained below. First, when a request to connect an external floppy disk is specified by a signal (a command may be used) based on the switch 14, the drive selection circuit 27 selects a floppy disk drive 12.1 built into the system.
A selection signal is supplied to drive No. 3 (either drive No. 1 (12) or drive No. 2 (23); drive No. 2 here). Here, settings are made such that, for example, outputs of drive select, motor 0N10FF, etc. are prohibited. Further, the output of the buffer 22 is disabled, and the output of the driver 24 is also disabled.

Note that the printer status is stored in the buffer 25.
Although this is possible, the CPU can recognize that the printer is not connected by assembling a circuit that puts the printer in the 0PEN state. Each signal sent from drive NO2 is sent to receiver 3.
Next to the signal via 0, the floppy disk control circuit 2
6. Output to the external floppy disk device 8 is performed by drivers 33 and 34. In addition, the drive select of the external floppy disk device 8 and the motor 0N10FF i are changed to the signal ■ by the driver 34.
■ Output on top via.

It should be noted that signals can be freely assigned to input/output signals to/from the external float-to-disk device 8 other than those shown in FIG. This allows the external floppy disk device 8 to be easily connected to the main body without having a dedicated floppy disk interface, thus contributing to improved cost performance.

Although the embodiments of the present invention have been described using a /4' personal computer system as an example, the present invention can be similarly applied to word processors and other office automation equipment. Furthermore, it is applicable to printer interfaces other than the Centro interface, and to interfaces other than printers. However, this application is limited to those whose output level is TTL level.

〔Effect of the invention〕

As explained above, according to the present invention, the following effects can be obtained.

(1) It becomes possible to connect an external floppy disk without having a dedicated floppy disk connection interface.

(2) A floppy disk of a different size from the floppy disk in the system can be connected to the outside.

(3) It is easy to cokey between floppy disk media of different sizes and to read data into the system.

(4) There is flexibility in changing the drive number of the external floppy disk.

(5) When building a floppy disk/hard disk system, users can easily add 70 disks.

[Brief explanation of drawings]

FIG. 1 is a block diagram showing an embodiment of the present invention, and FIG. 2 is a block diagram showing FIG. 1 in more detail. DESCRIPTION OF SYMBOLS 1... T printer control circuit, 2... Floppy disk control circuit, 7... Printer device, 8... Externally connected floppy disk device, 12. ...Switch, 2
1... Drive selection circuit, 32... Buffer, 33
・34...driver.

Claims (1)

[Claims] Data, which is the connection interface for input/output devices.
Command, status line and wired O
R Controls the output of the driver/buffer connected to the connected driver/buffer gate and the connection mode specified by an external instruction, and controls the input/output device control circuit or floppy disk control device according to each connection mode. A floppy disk connection interface device comprising a selection circuit for instructing.