Bi-directional digital game port driver

Abstract

The invention uses the conventional PC game port as a port for a digital game input device, employing a Digital Game Port (DGP) protocol which uses the four discrete or button lines and a single analog line (one of four) on the conventional game board to form a dual serial port. Data from a DGP control device is packetized with each packet consisting of 13 bytes of data. The packets or blocks are then grouped into frames. A frame consists of two blocks of data. A total of two frames are transmitted to the driver for each driver request. The 13-byte data block is divided between six one byte analog values and four bytes of digital data, with three bytes that identify and define the device. This device definition and identification is unique. By sending the device identification and configuration to the driver, the driver can determine not only the presence of the device but also very specific aspects of the device. The hardware configuration of the cable enables the driver to uniquely identify the first unit connected to the host computer as the master unit. The driver identifies the other units, if any, as slave units. Up to 3 additional slave units may be chained from the master digital game port input device by such cables.

Description

[0001] A portion of the disclosure of this patent document contains material that is subject to copyright protection. The copyright owner has no objection to the facsimile reproduction by anyone of the patent document or the patent disclosure, as it appears in the Patent and Trademark Office patent file or records, but otherwise reserves all copyright rights whatsoever.[0002] 1. Field of the Invention[0003] This invention relates generally to controllers for games and simulator programs implemented on a personal computer ("PC") and, more particularly, to bi-directional controller drivers having the capability of receiving transmitted digital controller data to the PC game port responsive to a PC microprocessor instruction.[0004] 2. Description of the Related Art[0005] The PC has been through a good deal of change and evolution since its initial introduction. However, in some areas, the PC has changed little. One such area is the way in which the PC interfaces to external devices. Co...

AI Technical Summary

Benefits of technology

[0031] The invention is a new method of using the existing game port interface, one that not only eliminates the inherent inconsistencies of the existing game port but also significantly expands the number of devices that can be connected to a single game port. There are several aspects of the invention and the manner in which it can be implemented that are both creative and unique. The invention uses the conventional PC game port in an entirely new way, as a port for a digital game port (DGP) input device or controller arranged and operating according to the invention, and in so doing uses the game port as a dual bit stream serial port.

[0032] As mentioned above, it is clear that the value of such analog inputs can change from machine to machine and from game card to game card depending upon speeds, components, etc. One way the invention eliminates this variation is to convert the analog position value of the device at the device and then to transmit the value in digital form to a receiving driver for further processing at the PC. This eliminates the dependence upon the variant elements of the PC and interface between the PC and the device. Commonly-assigned U.S. Pat. No. 5,593,350 to Bouton, discloses an analog-to-digital game card capable of converting analog inputs from a controller to digital representations and inputting them to the PC data bus responsive to a WRITE instruction from the PC microprocessor to the game card. The present invention enables digital input from the DGP controller through a conventional game card.

Problems solved by technology

Countless add-in cards and interfaces have been developed but, with few exceptions, these new add-in cards and interfaces have not become standard to the basic PC.

The keyboard port has also been adopted for bi-directional communications (See U.S. Pat. Nos. 5,396,267 and 5,610,631; see also U.S. Pat. No. 4,824,111 to Hoye, et al.) but does not provide a truly bi-directional interface.

One problem with the current system is that the primary bi-directional interface, the serial interface, has speed limitations and is typically dedicated to other external devices such as the printers.

Therefore, the serial interface has not been readily available to support game controllers.

Any input device lacking such compatibility will not be able to be used to interface with conventional personal computers through standard game boards and will not be widely accepted.

One problem is that the industry standard game port provides only a limited number of inputs: four discrete signal inputs for receiving discrete signals signifying "On" and Off" and four analog signal inputs for receiving variable voltage signals, such as output by a potentiometer, which are continuously variable over a limited range.

The number of game boards that could be plugged into a conventional PC was also limited.

Consequently, the number of controllers supported by a standard game port, and the number of allowable functions communicated thereby, is severely restricted.

Additionally, the game card or board has been typically thought of as an input only device, that is, not having the capability of communication to and from the external device.

A drawback is that the characteristics of the analog inputs can vary significantly from machine to machine.

Unfortunately, the aforementioned attempts to expand game port functionality have failed to fully address the limitations inherent in the conventional game board.

The existing discrete or binary input capabilities of a conventional game port, even augmented by a keyboard port input device, does not permit the implementation of such a wide range of control inputs.

Existing game controllers have not provided much improvement or simplification in the configuration of the game input devices or expansion of the number of external devices supported.

A related drawback is that a significant amount of microprocessor or driver time is spent in determining the position of the controller.

The advent of the Universal Serial Bus ("USB") might one day bypass these problems by increasing the number of bi-directional serial I / O ports on a PC, but that capability is not readily available as yet.

Moreover, USB cannot readily be implemented on tens of millions of PCs now in use which rely on a game port as the primary interface of joysticks and other game controllers to PCs.

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