Data base accessing system

• US 4,700,378 A
• Filed: 08/08/1985
• Issued: 10/13/1987
• Est. Priority Date: 08/08/1985
• Status: Expired due to Fees

• Current Assignee: Daniel Guerdon Brown
• Original Assignee: Daniel Guerdon Brown
• Inventors: Brown, Daniel G.
• Primary Examiner(s): George, Keith E.
• Application Number:
  US06/763,921
• Time in Patent Office: 796 Days
• Field of Search: 179/2 DP, 179/2 TV, 358/85, 178/22.01, 364/900 MS File, 379/53, 379/93, 379/95, 379/96, 380/3, 380/4
• US Class Current: 379/93.25
• CPC Class Codes: H04M 11/085 using a television receiver, e.g. viewdata system

Abstract

Inexpensive communication is provided between a data base and a plurality of subscribers each equipped with only a telephone and a TV set by using only tone signals to communicate from the subscribers to the data base, and data signals at least partially to communicate from the data base to the subscribers. For this purpose, each subscriber location needs to be provided with only the demodulator portion of a modem, and the base location needs to be provided only with the modulator portion of a modem and a tone decoder. A microprocessor-controlled security device is disclosed for remotely disabling a subscriber'"'"'s module in case of misuse.

Claims

1. A low-cost system for accessing a data base, comprising:

(a) a data base including a computer at a base location, said data base computer being accessible by digital commands;

(b) a telephone set at a subscriber location, said telephone set being capable of producing audio tones;

(c) a telephone line interconnecting said base location and said subscriber location;

(d) a display unit at said subscriber location for displaying data stored in said data base;

(e) tone decoder means connected to said telephone line and said data base at said data base location for translating audio tone information into digital commands for accessing said data base;

(f) a base module including modulator-only data transmitting means connected to said telephone line and said data base at said base location for transmitting digital data from said data base over said telephone line in response to said commands; and

(g) a subscriber module including

(i) demodulator-only data receiving means interconnecting said telephone line and said display means at said subscriber location for causing said display means to display said transmitted data;

(ii) a refresh memory;

(iii) video generating means for translating the contents of said refresh memory into a video display signal;

(iv) microprocessor means connected to said data receiving means and said refresh memory for storing in said refresh memory digital display data received by said receiving means; and

(v) self-disabling means responsive to the reception of a predetermined data code by said subscriber module for impeding operation of said subscriber module;

(h) whereby communication toward said data base is by means of audio tones alone, and communication from said data base is at least in part by means of digital signals.

2. The system of claim 1, in which said self-disabling means is a nonvolatile memory connected to said microprocessor means, and said microprocessor means is programmed to execute its program only if a predetermined enabling code is stored in said nonvolatile memory;

said microprocessor means being further programmed to erase said enabling code from said nonvolatile memory upon receipt of a predetermined data command by said microprocessor means.