KR19980056207U - Mount of portable computer that can supply peripheral devices using parallel port - Google Patents

Abstract

The parallel port of the mount, which expands the functionality of the portable computer and makes it convenient to use, and supplies the power to the peripheral device through the parallel port when connecting peripheral devices requiring power. A peripheral device connection determining means for determining a peripheral device connected to the parallel port, and a power supply means for supplying power to the parallel port, between the parallel port and the input / output control unit of the portable computer. The power supply means does not supply power when the connection determining means determines that the peripheral device is not connected to the parallel port or that the peripheral device that does not need to be supplied is connected, and the peripheral device connection determining means is connected in parallel. Power is determined when the port is connected to a peripheral device that requires power. The supply means supplies power to the peripherals through the parallel port.

Description

Mount of portable computer that can supply peripheral power using parallel port

The present invention extends the functionality of portable computers, such as notebook computers and laptop computers, to a parallel port provided in a mount of a docking station and a port replicator for convenient use. In the case of connecting peripheral devices that require power supply, it is related to a mount of a notebook computer that can supply peripheral devices using a parallel port that supplies power through a parallel port. The present invention relates to a mount of a portable computer capable of supplying power to peripheral devices by using a parallel port improved from No. 13117 (filed April 16, 1996).

Portable computer systems, including notebook computers and laptop computers, incorporate only the minimum amount of peripherals necessary to reduce the weight of the console.

Peripheral devices that are not built into the main body can be connected and used from the outside of the main body.

Peripheral devices that can be used outside the main body of a portable computer include a Floppy Disk Driver (FDD), a Compact Disk-Read Only Memory (CD-ROM) drive, a hard disk drive, and a printer.

1 is a perspective view illustrating a portable computer that can be used by selectively connecting a CD-ROM drive and an FDD to an interface connector.

Here, reference numeral 1 denotes a main body of the portable computer, and the interface connector 2 is provided on the front left side of the main body 1.

Reference numeral 3 denotes a removable CD-ROM drive, and reference numeral 4 denotes a removable FDD, which allows a user to selectively connect the CD-ROM drive 3 or the FDD 4 to the interface connector 2.

2 is a block diagram showing the configuration of a general portable computer. As shown in the drawing, a predetermined image is displayed on the central processing unit 10 that controls the operation of the portable computer, the ROM 20 and the RAM 30 as the storage device, and the display unit 40 as the display device. The display control unit 50 for controlling and the input / output control unit 60 for inputting and outputting external devices and data are connected to each other via a bus, and the input / output control unit 60 is connected in parallel with a peripheral device. The port 70, the auxiliary storage device 80, and the keyboard 90 are connected.

Since a portable computer having such a configuration includes only one interface connector 2 in the main body 1, only one of the CD-ROM drive 3 and the FDD 4 should be selected and connected to the interface connector 2. .

If you want to use both the CD-ROM drive (3) and the FDD (4) connected to a portable computer, connect any one of the CD-ROM drive (3) and FDD (4) to the interface connector (2) , The other one must be connected to the parallel port provided in the main body (1).

For example, the CD-ROM drive 3 is connected to the interface connector 2 as shown in FIG. 3A, and the FDD 4 is connected to the rear side 5 of the main body 1 as shown in FIG. 3B. It is connected to the parallel port 70 provided via the cable 6, and is used.

The parallel port 70 is a connection means used for transferring predetermined data between a portable computer and a peripheral device. The parallel port 70 is mainly connected to a printer and a network card. The CD-ROM drive 3 and the FDD 4 ) May be connected and used.

In addition, since the parallel port 70 is directly connected to the input / output control unit 60, when a peripheral device is connected to the parallel port 70, the input / output control unit 60 is in a state in which the pins of the parallel port 60 are connected. Accordingly, it recognizes which peripheral device is connected to the parallel port 70, and performs the operation accordingly.

The CD-ROM drive 3 and the FDD 4 do not have separate power supply means therein.

Therefore, when using a peripheral device that requires the supply of power, such as FDD (4) to the parallel port 70, it is necessary to supply power from the portable computer to the peripheral device.

However, since the parallel port 70 is not provided with a power supply pin, when a peripheral device requiring power supply is connected to the parallel port 70, power must be supplied separately from the portable computer.

In order to supply power from a portable computer to a peripheral device requiring power supply connected to the parallel port 70, a separate power supply cable is required.

For example, as shown in FIG. 3B, a cable 6 connecting the FDD 4 and the parallel port 70 to each other is used as the Y-type cable 7 in which a power supply line is integrally formed, and the Y-type cable ( A connector (not shown) is provided at an end of the power supply line of 7), and the connector is connected to a din jack 9 to which the keyboard 90 is connected and supplied to the keyboard 90. Power was supplied to the peripherals together.

In addition, when the peripheral port 70, for example, a CD-ROM drive 3, a hard disk drive, or the like, needs to be supplied from a portable computer to the parallel port 70, the FDD 4 and the like. Likewise, a separate power supply line was connected to the parallel port 70 and the din jack 9 of the keyboard 90 by using a cable.

According to this conventional technique, the Y-type cable 7 in which the power supply line is formed integrally with the cable 6 connecting the peripheral device and the parallel port 70, which requires the supply of power from the portable computer, must be used. 6,7) is very difficult to manufacture, and there was a problem that a separate connector for power supply should be provided.

When the portable computer is powered on and operated, when the peripheral device requiring power from the portable computer is connected to or disconnected from the parallel port 70, the din jack 9 to which the keyboard 90 is connected must be disconnected and connected. do.

When disconnecting and connecting the DIN jack 9 to which the keyboard 90 is connected, an abnormality occurs in the power supplied to the keyboard 90, thereby damaging the keyboard 90, and also damaging the FDD 4 and peripheral devices. .

Therefore, when disconnecting and connecting peripheral devices that require power from the portable computer, the portable computer must be turned off, which causes a lot of trouble for the user.

In order to solve such a conventional problem, the applicant has proposed a patent application No. 13117 in 1996.

In the 1996 patent application No. 13117, a peripheral device that requires a power supply from a portable computer or a peripheral device that does not need to supply power is provided between the input / output control unit and the parallel port provided on the rear of the main body. Peripheral device connection determination means for determining whether or not connected to the power supply means for supplying power from the portable computer to the peripheral device through the parallel port.

Discrimination signal of the peripheral device connection determining means when the peripheral device connection determining means determines that the peripheral device is not connected to the parallel port or that the peripheral device that does not need to supply power from a portable computer such as a printer is connected As a result, the power supply means does not supply power.

When the peripheral device connection determining means determines that the peripheral device that requires the supply of power from the portable computer is connected to the parallel port, the power supply means supplies power to the peripheral device through the parallel port according to the determination signal of the peripheral device connection determining means. To feed.

When the portable computer is connected to a mount such as a docking station and a port replicator, the parallel port provided in the portable computer is located inside the mount and is not exposed to the outside. Therefore, peripheral devices are provided in the parallel port provided in the portable computer. You can't connect it, but you need to connect a peripheral device to the parallel port on the mount.

The parallel port provided in the mount is not provided with a pin for supplying power to the peripheral device.

Therefore, when the portable computer equipped with the peripheral device connection determination means and the power supply means is mounted on the mount, the cable which is integrally provided with the power supply line is still used for the cable connecting the peripheral device. There was a problem that the power supply to the peripheral device by connecting the line to the DIN jack that the keyboard of the mount is connected to the connector.

Therefore, an object of the present invention is to determine the peripheral device connected to the parallel port provided in the mounting unit to supply power through the parallel port when the power supply is required, and the peripheral device that does not require power supply It is to provide a mount of a portable computer capable of supplying power to peripheral devices by using a parallel port to cut off the power supply.

In order to achieve the above object, a portable computer that can be supplied with a peripheral device using the parallel port of the present invention has a peripheral device that requires a power supply to a peripheral port or a peripheral device that does not require power supply. Peripheral device connection determination means for determining whether the device is connected, and a power supply means for supplying and disconnecting power through the parallel port of the mounting according to the determination signal of the peripheral device connection determination means.

When the peripheral device connection determining means determines that the peripheral device is not connected to the parallel port of the mounting table or determines that the peripheral device, such as a printer, that does not need to be powered by a portable computer, is connected, The power supply means does not supply power according to the discrimination signal.

When the peripheral device connection determining means determines that the peripheral device that requires the supply of power from the portable computer is connected to the parallel port of the mounting device, the power supply means is connected to the peripheral port through the parallel port of the mounting device according to the determination signal of the peripheral device connection determining means. Supply power to the equipment to operate it.

1 illustrates an example in which a CD-ROM drive and an FDD are selectively connected to an interface connector of a portable computer.

2 is a block diagram showing the configuration of a typical portable computer.

3A and 3B are diagrams illustrating a state in which a CD-ROM drive and an FDD are connected to a portable computer.

3A is a view showing a CD-ROM drive connected to an interface connector and FDD connected to a parallel port.

3B is a view showing a state in which the FDD is connected to the parallel port and the power supply line of the FDD is connected to the DIN jack.

4 is a view showing a state in which the portable computer is mounted on the mount.

5 is a view showing a connection relationship between the input / output control unit of the portable computer and the parallel port provided in the portable computer and the mounting according to the present invention.

Figure 6 is a detailed circuit diagram showing an embodiment of a mount of a portable computer capable of supplying power to peripheral devices using the parallel port of the present invention.

Explanation of symbols on the main parts of the drawings

3: CD-ROM drive

4: FDD

60: input / output control unit

70: first parallel port

71: first peripheral device connection determination means

72: first power supply means

100: mounting base

110: docking port

120: second parallel port

121: second peripheral device connection determination means

122: second power supply means

FET11, FET12, FET21, FET22: field effect transistor for ground

FET13, FET23: Field Effect Transistor for Peripheral Device Identification

FET14, FET24: field effect transistor for power supply

INV1, INV2: Inverter

R11, R12, R21, R22: resistor

Vcc1, Vcc2: Power

F1, F2: fuse

P19, P24, P20: first three pins

Hereinafter, with reference to the accompanying drawings of Figures 4 to 6 will be described in detail the mounting of the portable computer capable of supplying power to the peripheral device using the parallel port of the present invention, where the same reference numerals are given to the same parts as in the prior art. .

4 is a view showing a state where the portable computer is mounted on the mounting table.

Here, reference numeral 1 denotes a main body of the portable computer, and reference numeral 100 denotes a mounting table for a docking station, a port replicator, or the like which mounts the main body 1 of the portable computer to expand the function and make it convenient to use.

The mount 100 is provided with a docking port 110, when the main body 1 is mounted on the mount 100, the connector (not shown in the figure) provided in the main body 1 is It is connected to the docking port 110.

5 is a view illustrating a connection relationship between an input / output control unit of a portable computer and a parallel port provided in a main body and a mounting table of the portable computer according to the present invention.

Here, reference numeral 60 denotes an input / output control unit connected to a bus of the portable computer, reference numeral 70 denotes a first parallel port having 25 pins and installed in the main body 1 of the portable computer, and reference numeral 120 includes 25 pins It is a second parallel port installed in the mounting table 100.

Peripheral devices connected to the first and second parallel ports 70 and 120 are typically provided as spares without using pins 18 to 25 (P25).

Here, the present invention is an example of the first pin of the peripheral device when connecting the peripheral device requiring the supply of power through the cable 6 to the first parallel port 70 and the second parallel port 120 For example, when pin 19 is grounded and a peripheral device such as a printer that does not require power supply is connected, the second pin, for example, pin 24 is grounded, and power supply is The peripheral device in need is supplied with power through a third pin, for example, pin 20 (P20).

Reference numerals 71 and 121 denote first and second peripheral device connection determination means for determining a peripheral device connected to the first and second parallel ports 70 and 120. The first and second peripheral device connection determining means (71) 121 are grounded when the peripheral device requiring power supply is connected to the first and second parallel ports (70) (120). When the peripheral device is connected, it is determined whether the peripheral device is connected according to the signal of the first pin P19 and the second pin P24 which is grounded when the peripheral device that does not need the power supply is connected. Determine whether the peripheral device needed or the peripheral device that does not need power supply is connected.

Reference numerals 72 and 122 indicate that the first and second peripheral device connection determining means 71 and 121 are connected to the first and second parallel ports 70 and 120 to require peripheral devices. In this case, the first and second power supply means outputs power to the peripheral device through the third pin P20 of the first and second parallel ports 70 and 120.

Figure 6 is a circuit diagram showing an embodiment of a mount of a portable computer capable of supplying power to peripheral devices using the parallel port of the present invention.

As shown therein, the first and second peripheral device connection determining means 71 and 121 have a power source Vcc1 and Vcc2 connected to the first and second parallel ports 70 through the resistors R11 and R21. Connected to each other so as to be applied to the second pin P24 of 120, and a connection point of the resistors R11 and R21 and the second pin P24 of the first and second parallel ports 70 and 120 is grounded. The gates of the field effect transistors FET11, FET12 (FET21, FET22) and the input terminals of the inverters INV1 (INV2) are respectively connected.

Sources of the ground field effect transistors FET11 and FET12 (FET21 and FET22) are grounded, and drains of the ground field effect transistors FET11 and FET12 (FET21 and FET22) are connected to the first and second parallel ports 70. The first pin P19 and the third pin P20 of the 120 are respectively connected to each other.

The output terminal of the inverter INV1 (INV2) is connected to the gate of the field effect transistor FET13 (FET23) for peripheral device discrimination, and the source of the field effect transistor FET13 (FET23) for peripheral device discrimination is used for the ground. A field effect transistor for determining peripheral devices connected to the drain of the field effect transistors FET11 and FET12 (FET21 and FET22) and a connection point of the first pin P19 of the first and second parallel ports 70 and 120; The discrimination signal is output from the drain of FET13) (FET23).

The first and second power supply means (72, 122), the discrimination signal output from the first and second peripheral connection determination means (71) 121 is a power supply field effect transistor (FET14) ( It is connected to be applied to the gate of the FET24 and the input terminal of the input / output control unit 60, and to the connection point thereof, the power supply Vcc1 (Vcc2) is connected to be applied through the resistors R12 (R22), the power supply The power supply Vcc1 (Vcc2) is connected to the drain of the field effect transistor FET14 (FET24) via the fuse F1 (F2) so that the source of the power supply field effect transistor FET14 (FET24) is connected to the drain. The third pins P20 of the parallel ports 70 and 121 are respectively connected.

In the above, the power source Vcc1 is supplied from the main body 1 of the portable computer, and the power source Vcc2 is supplied from the mounting table 100.

The operation of the present invention configured as described above will be described in detail according to the type of peripheral device connected to the first parallel port 70 and the second parallel port 120.

1. When the portable computer is not connected to the mount and no peripheral device is connected to the first parallel port 70.

When no peripheral device is connected to the first parallel port 70, both the first pin P19 and the second pin P24 of the first parallel port 70 are open.

Then, the first peripheral device connection determining means 71 is applied to the input terminal of the inverter INV1 and the gate of the ground field effect transistor FET11 (FET12) through the resistor R11. INV1 outputs a low potential, and the ground field effect transistor FET11 (FET12) is turned off.

Due to the low potential output from the inverter INV1, the field effect transistor FET13 for peripheral device discrimination is brought into a conductive state.

At this time, since the peripheral device is not connected to the first parallel port 70, the first pin P19 is open, and the ground field effect transistor FET11 is blocked as described above. The drain of the effect transistor FET13 is opened.

Therefore, since the power supply Vcc1 is applied to the gate of the power supply field effect transistor FET14 through the resistor R12, the first power supply means 71 is turned off so that the power supply field effect transistor FET14 is turned off. 1 The power supply Vcc1 is not supplied to the third pin P20 of the parallel port 70.

In addition, since the power supply Vcc1 is input to the input / output controller 60 through the resistor R12, the portable computer determines that the peripheral device is not connected to the first parallel port 70.

2. When a peripheral device that requires power supply is connected to the first parallel port 70 without connecting the portable computer to the mount.

When a peripheral device that requires power supply is connected to the first parallel port 70, the first pin P19 of the first parallel port 70 is grounded through the peripheral device that requires power supply. The second pin P24 is in an open state.

Then, the first peripheral device connection determining means 71 is connected to the input terminal of the inverter INV1 and the ground field effect transistor FET11 via the resistor R11, similarly to the case where the peripheral device is not connected. Applied to the gate of (FET12), the inverter INV1 outputs a low potential, and the ground field effect transistors FET11 (FET12) are turned off.

The low potential of the first fin P19 is applied to the drain of the field effect transistor FET11 and the source of the field effect transistor FET13.

Therefore, the low potential output from the inverter INV1 causes the field effect transistor FET13 for peripheral device discrimination to be in a conductive state, and the low potential is output to the drain thereof.

As the low potential is output to the drain of the peripheral field discrimination field effect transistor FET13, the power supply Vcc1 flows to the drain of the field effect transistor FET13 through the resistor R12, and the power supply field effect transistor ( Since a low potential is applied to the gate of FET14, the power supply field effect transistor FET14 is brought into a conductive state.

Therefore, the power source Vcc1 is supplied to the peripheral device as an operating power source through the fuse F1, the power supply field effect transistor FET14, and the third pin P20 of the first parallel port 70.

At this time, when overcurrent flows to the peripheral device through the first parallel port 70, the overcurrent flows to the field effect transistor FET14 for power supply and is damaged.

Therefore, in the present invention, the fuse F1 is provided in the drain of the power supply field effect transistor FET14, and when the overcurrent flows to the power supply field effect transistor FET14, the fuse F1 is disconnected and the power supply field is supplied. Effect transistor FET14 is not damaged.

In addition, since the low potential output to the drain of the peripheral device discrimination field effect transistor FET13 of the first peripheral device connection determining unit 71 is input to the input terminal of the input / output control unit 60, the portable computer has a first parallelism. It is determined that the peripheral device which requires the supply of power to the port 70 is connected.

3. A peripheral device that does not require a power supply is connected to the first parallel port 70 without connecting the portable computer to the mount.

When a peripheral device such as a printer that does not require power supply is connected to the first parallel port 70, the first pin P19 is open, and the second pin P24 is connected to the first parallel port 70. Grounded through connected peripherals.

Then, the low potential of the second pin P24 of the first parallel port 70 is applied to the gate of the field effect transistors FET11 and FET12 for ground, and is inverted to high potential through the inverter INV1 to determine the peripheral device. Since it is applied to the gate of the field effect transistor FET13, the ground field effect transistor FET11 (FET12) becomes a conducting state, and the peripheral field discrimination field effect transistor FET13 becomes a blocking state.

As the peripheral field discrimination transistor FET13 is turned off, the power supply Vcc1 is applied to the gate of the power supply field effect transistor FET14 through the resistor R12, and thus the field effect transistor FET14 for power supply. ) Is cut off, and power is not output to the third pin P20 of the first parallel port 70.

In addition, since the power supply Vcc1 is input to the input / output controller 60 through the resistor R12, the portable computer determines that the peripheral device is connected to the first parallel port 70, and performs an operation accordingly.

4. When the portable computer is connected to the mount and no peripheral device is connected to the second parallel port 120.

When no peripheral device is connected to the second parallel port 120, both the first pin P19 and the second pin P24 of the second parallel port 120 are open.

Then, the second peripheral device connection determining means 121 is applied to the input terminal of the inverter INV2 and the gate of the ground field effect transistor FET21 (FET22) through the resistor R21. INV2 outputs a low potential, and the ground field effect transistors FET21 and FET22 are both shut off.

Due to the low potential output from the inverter INV2, the field effect transistor FET23 for peripheral device discrimination is brought into a conductive state.

At this time, since the peripheral device is not connected to the second parallel port 120, the first pin P19 is open and the ground field effect transistor FET21 is blocked as described above. The drain of the effect transistor FET23 is opened.

Therefore, since the power supply Vcc2 is applied to the gate of the power supply field effect transistor FET24 through the resistor R22, the second power supply means 122 is turned off so that the power supply field effect transistor FET24 is turned off. The power supply Vcc2 is not supplied to the third pin P20 of the second parallel port 120.

In addition, since the power supply Vcc2 is input to the input / output control unit 60 through the resistor R22, the portable computer determines that the peripheral device is not connected to the second parallel port 70 of the mounting apparatus 100. .

5. When a portable computer is connected to the mount and a peripheral device that requires power supply to the second parallel port 120 is connected.

When a peripheral device requiring power supply is connected to the second parallel port 120, the first pin P19 of the second parallel port 120 is grounded through the peripheral device requiring power supply. The second pin P24 is in an open state.

Then, the second peripheral device connection determination unit 121, as in the case where the peripheral device is not connected, the power supply (Vcc2) through the resistor (R21) and the input terminal of the inverter INV2 and the ground field effect transistor (FET21) Applied to the gate of FET22, the inverter INV2 outputs a low potential, and the ground field effect transistor FET21 (FET22) is turned off.

The low potential of the first fin P19 is applied to the drain of the field effect transistor FET21 and the source of the field effect transistor FET23.

Thus, the low potential output from the inverter INV2 causes the field effect transistor FET23 for peripheral device discrimination to become conductive, and the low potential is output to the drain thereof.

As the low potential is output to the drain of the field effect transistor FET23 for determining the peripheral device, the power supply Vcc2 flows to the drain of the field effect transistor FET23 through the resistor R22, and the power supply field effect transistor ( Since a low potential is applied to the gate of FET24, the power supply field effect transistor FET24 is brought into a conductive state.

Therefore, the power source Vcc2 is supplied to the peripheral device as an operating power source through the fuse F2, the power supply field effect transistor FET24, and the third pin P20 of the second parallel port 120.

Here too, when the overcurrent flows to the peripheral device through the second parallel port 120, the overcurrent flows to the power supply field effect transistor FET24 and is damaged. In the present invention, the power supply field effect transistor FET24 When overcurrent flows to the power supply field effect transistor FET24 by providing the fuse F2 in the drain, the fuse F2 is disconnected, and the power supply field effect transistor FET24 is not damaged.

In addition, since the low potential output to the drain of the field effect transistor FET23 for determining the peripheral device of the second peripheral device connection determining unit 121 is input to the input terminal of the input / output control unit 60, the portable computer has a second parallelism. It is determined that the peripheral device that requires the supply of power is connected to the port 120.

6. When a portable computer is connected to the mount and a peripheral device that requires no power supply is connected to the second parallel port 120.

When a peripheral device such as a printer that does not need a power supply is connected to the second parallel port 120, the first pin P19 is in an open state, and the second pin P24 is connected to the second parallel port 120. Grounded through connected peripherals.

Then, the low potential of the second pin P24 of the second parallel port 120 is applied to the gates of the field effect transistors FET21 and FET22 for ground, and is inverted to high potential through the inverter INV2 to determine the peripheral device. Since it is applied to the gate of the field effect transistor FET23, the ground field effect transistor FET21 (FET22) is in a conducting state, and the peripheral field discrimination field effect transistor FET23 is in a blocking state.

As the peripheral field discrimination transistor FET23 is turned off, the power supply Vcc2 is applied to the gate of the power supply field effect transistor FET24 through the resistor R22, and thus the power supply field effect transistor FET24. ) Is cut off and power is not output to the third pin P20 of the second parallel port 120.

Since the power supply Vcc2 is input to the input / output controller 60 through the resistor R22, the portable computer determines that the peripheral device is connected to the second parallel port 120, and performs an operation accordingly.

Meanwhile, in the above, the first peripheral device connection determining unit 71 and the first power supply unit 72 are provided between the input / output control unit 60 and the first parallel port 70 of the portable computer. As an example, the second peripheral device connection determining unit 121 and the second power supply unit 122 are provided between the output control unit 60 and the second parallel port 120 of the mounting table 100.

In carrying out the present invention, the present invention is not limited thereto, and the second peripheral device connection determination unit 121 and the second power supply are provided only between the input / output control unit 60 and the second parallel port 120 of the mounting table 100. The means 122 can also be provided.

As described above, the present invention determines a peripheral device connected to the parallel port of the mount when the portable computer is mounted on the mount, so that the power is supplied through the parallel port when a peripheral device requiring power supply is connected, By turning off the power supply when a peripheral device is not required to supply power, you can easily connect the peripheral device to the mount and simply connect and disconnect the peripheral device to the parallel port even when the portable computer is turned on. have.

Claims (5)

A second parallel port provided on a mount to which a portable computer is connected, a first peripheral connected to the second parallel port and a first pin indicating a need for supply of power, and connected to the second parallel port And a second peripheral device having a second pin grounded to indicate that no power supply is required, and between the second parallel port and the input / output control unit of the portable computer, and in the state of the first pin and the second pin. A second peripheral device connection determining means for determining whether a first peripheral device or a second peripheral device is connected to the second parallel port; and the second peripheral device connection determining means includes a first peripheral device connected to the second parallel port. And a second power supply means for supplying power through the third pin of the second parallel port when it is determined that the connection is made. Mounting of portable computer power supplies available for. The method according to claim 1, wherein whether the first peripheral device or the second peripheral device is connected between the portable computer and the first parallel port provided in the portable computer in the state of the first pin and the second pin of the first parallel port. The first peripheral device connection determining means for determining and the first peripheral device connection determining means for supplying power through the third pin of the first parallel port when the first peripheral device is determined to be connected to the first parallel port. A mounting table of a portable computer capable of supplying power to a peripheral device by using a parallel port, characterized in that it comprises a first power supply means for supplying. The said 1st and 2nd peripheral device connection discrimination means is an inverter which inverts the signal of the said 2nd pin, and is made into the conduction state and the interruption state according to the output signal of the said inverter, The said 1st A mount of a portable computer capable of supplying power to peripheral devices using a parallel port, characterized in that it comprises a field effect transistor for discriminating peripheral devices that outputs a pin signal as a discrimination signal. The method according to claim 3, wherein the first and second peripheral device connection determining means, characterized in that it comprises a field effect transistor for grounding each of the first pin and the third pin when the ground is grounded. A portable computer mount that can be used to power peripheral devices using a parallel port. The method according to claim 1 or 2, wherein the first and second power supply means, when the first and second peripheral device connection determining means outputs a determination signal for determining that the first peripheral device is connected to the parallel port And a power supply field effect transistor for supplying power to the first peripheral device through a third pin of the parallel port.