JPS62248054A - Bus modem - Google Patents

Abstract

PURPOSE:To obtain a bus MODEM which can control an unnecessary radiation, by forming a P/S converting part, a MODEM part, a network controller a memory part, and a DC/DC converter, on one piece of substrate. CONSTITUTION:A bus MODEM is provided with a bus line terminal 1 which can be connected to the bus line of a personal computer, a P/S converting part 2, a MODEM part 3, an NCU 4, a memory part 5 for storing a communication software, an address decoder 6 for giving an address to the converting part 2 and the memory part 5, a DC/DC converter 7, a line jack 8, and a telephone set jack 9. Other elements than the jack 8 and 9 are all formed on one piece of substrate. In this way, an unnecessary radiation is suppressed.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a bus modem, and particularly to a small and easy-to-handle bus modem that can provide inexpensive personal computer (hereinafter referred to as personal computer) communication.

[Conventional technology]

Conventionally, communication using a personal computer is performed by connecting a personal computer having an R3232C terminal to a telephone line via a modem.

FIG. 7 is a diagram for explaining an outline of a personal computer and a modem used for conventional personal computer communication.

A personal computer 700 having an R3232C terminal is equipped with an R3232C interface 702 connected to a bus line 701, and this R5232C interface is connected to an R5232C signal section 703 and an address decoder 7.
04 and a buffer 705, and the buffer 705 is connected to the R5232C terminal 706.

R3232C terminal 706 is connected to NCU modem 720 via R3232C connection cable 710. This modem 720 is composed of a buffer 721, a modem section 722, and a network control unit (NCU) 723.

Modem 720 is connected to rosette 74 via telephone line 730.
Connected to 0.

In the conventional apparatus as described above, communication software is supplied to the personal computer 700 using a floppy disk or magnetic tape to perform personal computer communication.

[Problem that the invention seeks to solve]

According to the conventional PC communication as described above, R323
Computers with 2C terminals are expensive, and communication software using expensive floppy disks or magnetic tape must be separately supplied to the computer.Also, a special R3232C cable is used to connect the computer and the modem, and the modem There were various drawbacks, such as the device being expensive because it had to be supplied with a power source, the device as a whole not being compact, and the computer and modem being separate, making it difficult to handle. .

The purpose of the present invention is to solve the above-mentioned problems by making it possible to connect directly to the lotus line that all computers have, even if the computer does not have an R3232C terminal, and to connect it directly to the computer itself. The purpose of the present invention is to realize an inexpensive personal computer communication system by providing a cartridge-type bus modem that can be used.

Another object of the present invention is to provide a bus modem that can be applied to inexpensive personal computers other than the MSX standard.

Still another object of the present invention is to provide a bus modem that can suppress unnecessary radiation.

[Means for solving problems]

A first aspect of the present invention is a parallel/serial bus modem that can be inserted into a ROM cartridge slot of a personal computer and directly connected to a bus line of the personal computer, and that converts between parallel and serial signals. a converting section, a modem section that modulates and demodulates the serial signal and the acoustic signal, and a network control device;
The device is characterized in that a memory unit that stores communication software and a DC/DC converter that converts DC voltage obtained from a personal computer are formed on a single substrate.

The second aspect of the present invention is a bus modem that can be inserted into a 20M cartridge slot of a personal computer and directly connected to the bus line of the personal computer, and that converts between parallel and serial signals. a conversion unit, a modem unit that performs modulation and demodulation between the serial signal and the acoustic signal, and a network control device;
A memory unit that stores communication software, a DC/DC converter that converts DC voltage obtained from a personal computer, and a low-pass filter connected to the line side of the network control device are formed on a single substrate. It is characterized by

〔Example〕

FIG. 1 is a block diagram showing an embodiment of the bus modem of the present invention.

This bus modem includes a bus line terminal 1 that can be connected to a bus line of a personal computer, a P/S converter 2 that converts between a parallel signal and a serial signal, a modem section 3, and an NC
U4, a memory section 5 consisting of a ROM, for example, that stores communication software, an address decoder 6 that gives addresses to the P/S conversion section 2 and the memory section 5, and a DC 5
It is equipped with a DC/DC converter 7 for converting into a DC/DC converter 7, a liner, a liner 8, and a telephone jack 9. Ja・
All elements except for the blocks 8 and 9 are formed on a single substrate.

FIG. 2 is a circuit diagram showing an example of the NCU 4.

This NCU consists of two interlocking changeover switches 21,2.
2, when these switches are turned on, the line jack 8 is connected to the modem section 3 via the relay wire ring 23, and when these switches are turned off, the line jack 8 is connected to the telephone jack 9. Further, since this NCU has a simple configuration as shown, it can be provided at low cost.

FIG. 3 is a circuit diagram showing an example of the DC/DC converter 7. This DC/DC converter is a DC 5
It has a simple structure that converts V to 12 V DC, and 5 V DC is supplied from the main body of the personal computer into which the bus modem of this embodiment is inserted. The bus modem of this example requires DC 5V and 12V for its operation, but since it has a built-in C/DC converter, it is not compatible with the MSX standard, which has only 5 ■ power supply terminals. It can also be used in inexpensive computers.

FIG. 4 shows the external appearance of the bus modem of this embodiment.

The Hasmodem is housed in, for example, a plastic container 40 having the same shape as a ROM cartridge, and the above-mentioned line jack 8 and telephone jack 9 are provided on the side of the container. In the figure, 41 is a line connection switch;
42 is a line connection indicator lamp. By turning ON and OFF the line connection changeover switch 41, the two changeover switches 21 and 22 of NCtJ4 explained in FIG. 2 are turned ON.
, turns off.

FIG. 5 is a diagram for explaining how the bus modem of this embodiment is used. By inserting the bus modem 51 into a slot of the personal computer 52, the bus line terminal 1 (FIG. 1) can be connected to the bus line of the personal computer 52. Line jack 8 is connected to rose throat 53, and telephone jack 9 is connected to telephone 54. In addition, in the figure, 5
Reference numeral 5 indicates a television connected to the personal computer, and reference numerals 56 and 57 indicate a cassette floppy disk as external memory.

When communicating with a personal computer using the MM-type Babass modem 51 of this embodiment, the telephone 54 sends out dial signals, detects incoming calls, and detects responses. For example, when transmitting data, first the line connection changeover switch 41 (the fourth
) is turned off, and the telephone 54 sends out a dial signal to call the other party. Next, turn on the line connection changeover switch 41 and connect the line to the relay ring 23.
(Fig. 2). Thereafter, according to the communication software stored in the memory unit 5, from the bus line of the personal computer 52 to the bus line terminal 1 of the bus modem, P/S'1mR
fS2) Data is sent to the telephone line via the modem section 3, NCU 4, and line jack 8.

The bus modem described above has built-in communication software and a DC/DC converter, so for example,
Can be used with inexpensive computers that do not meet the SX standard, and is NC1J
, DC/DC converter, etc., making it possible to realize inexpensive personal computer communication as a whole.

Furthermore, since the bus modem has a structure that allows it to be attached directly to the computer itself, there is no need for a conventional cable to connect the computer and the modem, making it extremely compact. In addition, since the computer and bus modem are integrated, it is easier to carry, and since you can operate switches and check lamps at hand, it is easier to handle and the price of the case is lower. .

Now, as shown in FIG.
If the bus modem 51 and the line connected to the bus modem are connected, there is a risk that the television image will be visible due to unnecessary beam radiation generated from the bus modem 51 and the line connected to the bus modem.

Another embodiment for preventing this is shown in FIG. This bus modem is equipped with a low-pass filter 60 between the NCU 4 and the line jack 8 to pass frequencies below 3 to 4 kHz, which is the telephone frequency, and filter out the MHz band. I am trying to suppress the radiation. Note that the other elements are the same as those of the bus modem shown in FIG.

Further, by covering the inside of the container shown in FIG. 4 with aluminum foil or vapor-depositing aluminum to form a shield structure and grounding this, unnecessary radiation generated from the bus modem itself is suppressed.

According to the bus modem of this embodiment, clear images can be obtained.

〔Effect of the invention〕

As explained above, according to the present invention, very inexpensive personal computer communication can be realized. For example, by using the HAS modem of the present invention, it becomes possible to perform personal computer communication at half the cost of conventional methods.

Further, since the bus modem of the present invention has a structure that can be directly connected to a personal computer, it is compact and extremely easy to handle.

Furthermore, according to the bus modem of the present invention, unnecessary beam radiation can be suppressed, so when a television is connected to a personal computer,
A clear image that is not affected by noise can be maintained.

[Brief explanation of drawings]

FIG. 1 is a block diagram showing an embodiment of the present invention, FIG. 2 is a circuit diagram showing an example of the NCU shown in FIG. 1, and FIG. 3 is an example of the D C/DC converter shown in FIG. 1. 4 is a diagram showing the external appearance of the bus modem in FIG. 1, FIG. 5 is a diagram showing how the bus modem in FIG. 1 is used, and FIG. 6 is a diagram showing another embodiment of the present invention. The figure shown in FIG. 7 is a diagram showing a conventional device. ■...Bus line terminal 2...P/S converter 3...Modem section 4...NCU 3...Memory section 6...Address Decoder 7...D C/DC converter 8...Line jack 9...Telephone jack 2L22...Selector switch 23...Relay wire ring 40...Plastic Container 41...Line connection changeover switch 42...
Line connection indicator lamp 51... Bus modem 52... Personal computer 53... Rosette 54... Telephone 55... Television 56... Cassette tape 57 ... Floppy disk 700 ... Personal computer 701 ... Bus line 702 ... R3232C interface 70
3...R3232C signal section 704...
Address decoder 705...Buffer 706...R3232C terminal 710...R3232C connection cable 720
...NCU modem 721 ...Buffer 722 ...Modem section 723 ...NCU 730 ...Telephone line 740 ...Rosette

Claims (4)

[Claims] (1) A bus modem that can be inserted into a ROM cartridge slot of a personal computer and directly connected to the personal computer's bus line, and that converts between parallel and serial signals.
a serial conversion section, a modem section that performs modulation and demodulation between the serial signal and the acoustic signal, a network control device, a memory section that stores communication software, and a DC/DC converter that converts the DC voltage obtained from the personal computer. A bus modem characterized in that: and are formed on a single board. (2) The bus modem according to claim 1, wherein the board is housed in one container. (3) A bus modem that can be inserted into a ROM cartridge slot of a personal computer and directly connected to the personal computer's bus line, and that converts between parallel and serial signals.
a serial conversion section, a modem section that performs modulation and demodulation between the serial signal and the acoustic signal, a network control device, a memory section that stores communication software, and a DC/DC converter that converts the DC voltage obtained from the personal computer. and a low-pass filter connected to the line side of the network control device are formed on a single substrate. (4) The bus modem according to claim 3, wherein the board is housed in a single container that is internally shielded.