Device for maintaining game state audit trail upon instantaneous power failure

• US 4,948,138 A
• Filed: 10/21/1985
• Issued: 08/14/1990
• Est. Priority Date: 12/06/1982
• Status: Expired due to Term

• Current Assignee: IGT (International Game Technology)
• Original Assignee: IGT (International Game Technology)
• Inventors: Wells, William, Pease, Logan L.
• Primary Examiner(s): Coven, Edward M.
• Assistant Examiner(s): Small, Dean
• Application Number:
  US06/789,356
• Time in Patent Office: 1,758 Days
• Field of Search: 371/10, 371/14, 371/28, 371/66, 273/85 G, 273/DIG. 28, 273/1 E, 273/138 A
• US Class Current: 463/24
• CPC Class Codes: G06F 1/30 Means for acting in the event of power-supply failure or interruption, e.g. power-supply fluctuations for resetting only G06F1/24
• CPC Class Codes: G06F 11/14 Error detection or correction of the data by redundancy in operation G06F11/16 takes precedence

Abstract

A look ahead state saving device for maintaining an audit trail of a plurality of discrete, sequential operating states in an electronic machine, such as a gaming machine. Each such state include accompanying operational data. A nonvolatile solid state memory maintains the audio trail. Game operation is initially interrupted and, thereafter, current state data is frozen in the memory when power source unreliability is detected and reliable machine operation cannot be maintained. The device retrieves the most recent game states and operational data from the memory upon restoration of power source reliability. Memory nonvolatility is maintained by a back-up battery source that includes a battery low detection circuit for interrupting machine operation in the event of battery failure, and that also includes a battery charging circuit.

Claims

1. A look-ahead state saving device for processor controlled interactive electronic game played by a game player, operated from a game power source, and having an operating cycle including a plurality of discrete sequential interactive game states accompanied by interactive game state dependent data, comprising:

a nonvolatile solid state memory for providing a continually updated audit trail of interactive game states and accompanying interactive game state related data characterizing the interaction of a game player and the game for a particular interactive game state;

means for continually producing a reset signal for resetting said memory;

comparator means for detecting a game power source level less than that of a game operating reference level;

means for producing a game interrupt signal wherein game operation is interrupted at a current interactive game state in response to comparator detection of a game power source level less than the game operating reference level;

means for producing a memory freeze signal to prevent memory reset, said signal being produced a preselected time interval after production of said game interrupt signal in response to comparative detection of said game power source level less than the game operating reference level, wherein said interactive game state and accompanying interactive state related data are retained in said memory after completion of a current game state whereby said retained interactive game state and interactive state related data provide for error free resumption of game play.

2. The state saving device of claim 1, further comprising:

means for clearing said memory.

3. The state saving device of claim 1, further comprising:

a back-up battery source for maintaining data in said memory in the event of power interruption.

4. The state saving device of claim 3 further comprising:

means for detecting a battery condition and for producing said game interrupt and memory freeze signals upon detection of said battery low condition.

5. In a processor controlled interactive electronic game played by a game player having an operating cycle including a plurality of sequential interactive game states, and wherein each game state includes accompanying interactive game state dependent data, a method for saving interactive game operating states and interactive game state related data during game power source interruption, comprising the steps of:

maintaining a continually updated audit trail of the most recent interactive state and its accompanying interactive game state related data characterizing the interaction of a game player and the game for a particular game state in a continually reset nonvolatile solid state memory;

interrupting game operation after completion of a current interactive game state when a power source coupled to said game is unable to maintain reliable game operation;

freezing said current interactive game state and interactive game state dependent data in said memory to prevent memory reset, said freezing occurring a selected time interval after interruption of game operation; and

retrieving said current interactive game state and its accompanying interactive game state related data from said memory to resume game operation at its last interactive state before power source interruption, upon resumption of power source reliability.