Personal computer system allowing selective use of built-in and external keyboards by means of selector

Claim 2

A portable computer system comprising: a main body having a central processing unit, a system bus, an external keyboard connector, and a built-in keyboard; an external keyboard of a type different from said built-in keyboard, removably connected to the main body through the external keyboard connector; a keyboard controller included in the main body, having a system bus interface connected to the system bus to send/receive data to/from the central processing unit, and a keyboard interface for sending/receiving signals to/from one of the built-in and the external keyboards, and capable of receiving keyed-in data from one of the built-in and the external keyboards and for transmitting the keyed-in data received to the central processing unit; and a selecting circuit, included in the main body and connected to said keyboard interface, said built-in keyboard, and said external keyboard connector, for connecting said keyboard interface to one of said built-in and said external keyboards through said external keyboard connector.

Claim 3

A portable computer system according to claim 1, wherein said computer system further comprises control signal supply means for supplying a selection control signal to the selecting circuit, said control signal supply means includes a register which stores data which is supplied to said selecting circuit as the selection control signal, and said selecting circuit selects one of the keyboards in accordance with the selection control signal.

Claim 4

A portable computer system according to claim 2, wherein said central processing unit detects whether or not the external keyboard is connected to the main body, said central processing unit writes first data in the register, to thereby cause the selecting circuit to select the external keyboard, when the central processing unit detects that the external keyboard is connected to the main body, and writes second data in the register, to thereby cause the selecting circuit to select the built-in keyboard, when the central processing unit detects that the external keyboard is disconnected from the main body.

Claim 5

A portable computer system according to claim 2, further comprising information storage means for storing keyboard-designation information which is entered by an operator, said central processing unit determining the contents of the data stored in the register, on the basis of the keyboard-designation information stored in the information storage means.

Claim 6

A portable computer system according to claim 2, further comprising a hardware switch to be turned on or off by an operator, the contents of the data stored in said register being determined depending upon the ON/OFF state of the hardware switch.

Claim 7

A portable computer system according to claim 1, further comprising a first scan controller, connected between the selecting circuit and the built-in keyboard, said first scan controller detecting a depressed key of the built-in keyboard by scanning a key matrix of the built-in keyboard, and generating key code data corresponding to the depressed key.

Claim 8

A portable computer system according to claim 6, wherein said external keyboard includes a second scan controller which detects a depressed key of the external keyboard by scanning a key matrix of the external keyboard, and generates key code data corresponding to the depressed key.

Claim 9

A portable computer system according to claim 1, further comprising scan controller connected between the interface of the keyboard controller and the selecting circuit, said scan controller detecting a depressed key of one of the built-in and external keyboards by scanning a key matrix, and generating key code data corresponding to the depressed key.

Claim 10

A portable computer which an external keyboard can be removably connected, the portable computer comprising: a housing including a central processing unit (CPU), a connector removably and electrically connected to the external keyboard, and a bus electrically connected to the CPU; a built-in data input means for inputting data, wherein the built-in data input means is located in the housing and is different in type from the external keyboard; a controller located in the housing including first and second interfaces, the first interface being electrically connected to the bus, wherein the first interface communicates with the CPU and the second interface receives signals from one of the built-in data input means and the external keyboards; and a selector located in the housing and connected to the second interface, the built-in data input means, and the connector, wherein the selector connects the second interface to one of the built-in data input means and the eternal keyboard through the connector.

Claim 11

A portable computer which an external keyboard can be removably connected, the portable computer comprising: a housing including a central processing unit (CPU), a connector removably and electrically connected to the external keyboard, and a bus electrically connected to the CPU; a built-in data input means for inputting data, wherein the built-in data input means is located in the housing and is different in type from the external keyboard; a controller located in the housing including first and second interfaces, the first interface being electrically connected to the bus, wherein the first interface communicates with the CPU and the second interface receives signals from one of the built-in data input means and the external keyboards; and a selector located in the housing and connected to the second interface, the built-in data input means, and the connector, wherein the selector connects the second interface to one of the built-in data input means and the eternal keyboard through the connector.

Claim 12

A portable computer according to claim 9, wherein the housing includes control signal supplying means for supplying a selection control signal to the selector, and the selector selects one of the built-in data input means and the external keyboard in accordance with the selection control signal.

Claim 13

A portable computer according to claim 9, wherein the housing includes a register which stores selection data from selecting one of the built-in data input means and the external keyboard, and the selector selects one of the built-in data input means and the external keyboard in accordance with the selection data.

Claim 14

A portable computer according to claim 11, wherein the housing includes control means for detecting whether or not the external keyboard is connected to the connector, the control means writes a first data in the register when the control means detects that the external keyboard is connected to the connector, the control means writes a second data in the register when the control means detects that the external keyboard is not connected to the connector, and the selector selects the external keyboard when the first data is written in the register and selects the built-in data input means when the second data is written in the register.

Claim 15

A portable computer according to claim 12, wherein the housing includes data storage means for storing designating data entered by an operator, and the control means writes one of the first and the second data in the register in accordance with the designating data.

Claim 16

A portable computer according to claim 11, wherein the housing includes a switch which is movable between a first position and a second position, wherein a first data for selecting the external keyboard by the selector is written in the register when the switch is at the first position and a second data for selecting the built-in data input means is written the register.

Claim 17

A portable computer according to claim 9, wherein the built-in data input means is an internal keyboard having a plurality of key-tops.

Claim 18

A portable computer to which an external keyboard can be removably connected, the portable computer comprising: a housing including a central processing unit (CPU), a connector removably and electrically connected to the external keyboard, and a bus electrically connected to the CPU; a built-in data input means for inputting data, wherein the built-in data input means is located in the housing and is different in type from the external keyboard; and a controller circuit, including a keyboard control circuit and a selector circuit, located in the housing, wherein the keyboard control circuit has a first interface electrically connected to the bus to communicate with the CPU and a second interface to receive signals from one of the built-i data input means and the external keyboard, and the keyboard control circuit receives signals when the external keyboard is electrically connected to the connector, and wherein the selector circuit is connected to the second interface, the built-in data input means, and the connector, and the selector circuit connects the second interface to one of the built-in data input means and the external keyboard through the connector.

Claim 19

A portable computer to which an external keyboard can be removably connected, the portable computer comprising: a housing including a central processing unit (CPU), a connector removably and electrically connected to the external keyboard, and a bus electrically connected to the CPU; a built-in data input means for inputting data, wherein the built-in data input means is located in the housing and is different in type from the external keyboard; and a controller circuit, including a keyboard control circuit and a selector circuit, located in the housing, wherein the keyboard control circuit has a first interface electrically connected to the bus to communicate with the CPU and a second interface to receive signals from one of the built-i data input means and the external keyboard, and the keyboard control circuit receives signals when the external keyboard is electrically connected to the connector, and wherein the selector circuit is connected to the second interface, the built-in data input means, and the connector, and the selector circuit connects the second interface to one of the built-in data input means and the external keyboard through the connector.

Claim 20

A portable computer according to claim 16, wherein the housing includes a register which stores selection data from selecting one of the built-in data input means and the external keyboard, and the selector circuit selects one of the built-in data input means and the external keyboard in accordance with the selection data.

Claim 21

A portable computer according to claim 17, wherein the housing includes control means for detecting whether or not the external keyboard is connected to the connector, the control means writes a first data in the register when the control means detects that the external keyboard is connected to the connector, the control means detects the external keyboard is not connected to the connector, the selector circuit selects the external keyboard when the first data is written in the register, and selects the built-in data input means when the second data is written in the register.

Claim 22

A portable computer according to claim 18, wherein the housing includes data storage means for storing designating data entered by an operator, and the control means writes one of the first and the second data in the register in accordance with the designating data.

Claim 23

A portable computer according to claim 17, wherein the housing includes a switch movable between a first position and a second position, wherein a first data for selecting the external keyboard by the selector is written in the register when the switch is at the first position, and a second data for selecting the built-in data input means by the selector is written in the register.