Data processing device having memory selectively interfacing with computer
First Claim
1. A portable data processing device for selective interfacing with a digital computer, said portable data processing device comprising:
- central processing means for controlling the operation of the device;
operator input means operably coupled to said central processing means for introducing input data from a user into the device for processing by said central processing means;
presentation means operably coupled to said central processing means for providing data information to the user;
memory means for storing data therein for subsequent accessing by said central processing means;
a primary power source operably coupled to said central processing means and said memory means;
first circuitry means interposed between said central processing means and said memory means for providing communication between said central processing means and said memory means in a first state to enable said central processing means to access data from said memory means and for prohibiting communication between said central processing means and said memory means in a second state;
connector means for electrical coupling to the computer, said connector means being operably coupled to said memory means, said primary power source, and said first circuitry means for interfacing the portable data processing device with the computer;
second circuitry means interposed between said memory means and said connector means for providing communication between said memory means and the computer in a first state to enable the computer to access data from said memory means when said connector means is electrically coupled to the computer and for prohibiting communication between said memory means and the computer in a second state;
said first and second circuitry means being operable in tandem such that only one of said central processing means or the computer can access said memory means at one time;
said memory means includinga non-volatile read-only-memory having program instructions stored therein for access by said central processing means in controlling the operation of the device, anda random access memory for storing data therein and being alternatively accessible by said central processing means or the computer when electrically coupled to said connector means depending upon the states of said first and second circuitry means such that either said central processing means or the computer is capable of writing data into and reading data from said random access memory when enabled; and
a back-up power source connected to said random access memory to provide power thereto for preserving data stored therein when said primary power source has been rendered inoperable.
1 Assignment
0 Petitions
Accused Products
Abstract
A portable educational device that is adapted to be used in conjunction with a counter (12) having a display (14) and a keyboard (16) for input of data. A memory slot (18) or an alternate port (19) is provided on the computer (12) to receive the educational device (20). Educational device (20) contains a keypad (24) and a display (26) and operates independent of the computer (12). The educational device (20) includes a central processing unit (48), a Read Only Memory (42) and a Random Access Memory (44). A primary power source (54) supplies power to the educational device (20) during the operation thereof. A back-up power source (56) provides power to the Random Access Memory (44) to form a non-volatile memory for retention of data during periods of non-use. A connector (34) interfaces with the computer (12) to allow the computer (12) to address the Random Access Memory (44) to retrieve data stored therein and to store data at selected locations therein for use by the Central Processing Unit.
140 Citations
15 Claims
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1. A portable data processing device for selective interfacing with a digital computer, said portable data processing device comprising:
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central processing means for controlling the operation of the device; operator input means operably coupled to said central processing means for introducing input data from a user into the device for processing by said central processing means; presentation means operably coupled to said central processing means for providing data information to the user; memory means for storing data therein for subsequent accessing by said central processing means; a primary power source operably coupled to said central processing means and said memory means; first circuitry means interposed between said central processing means and said memory means for providing communication between said central processing means and said memory means in a first state to enable said central processing means to access data from said memory means and for prohibiting communication between said central processing means and said memory means in a second state; connector means for electrical coupling to the computer, said connector means being operably coupled to said memory means, said primary power source, and said first circuitry means for interfacing the portable data processing device with the computer; second circuitry means interposed between said memory means and said connector means for providing communication between said memory means and the computer in a first state to enable the computer to access data from said memory means when said connector means is electrically coupled to the computer and for prohibiting communication between said memory means and the computer in a second state; said first and second circuitry means being operable in tandem such that only one of said central processing means or the computer can access said memory means at one time; said memory means including a non-volatile read-only-memory having program instructions stored therein for access by said central processing means in controlling the operation of the device, and a random access memory for storing data therein and being alternatively accessible by said central processing means or the computer when electrically coupled to said connector means depending upon the states of said first and second circuitry means such that either said central processing means or the computer is capable of writing data into and reading data from said random access memory when enabled; and a back-up power source connected to said random access memory to provide power thereto for preserving data stored therein when said primary power source has been rendered inoperable. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15)
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Specification