Abstract: A method and system for controlling access to various tiers of functionality of core software are provided. A software developer/vendor can develop a single version of software having one or more limited-access functionalities and provide the single version of the software to various types of customers. Each customer, using the single version of the core software, may develop additional software that utilizes one or more functionalities of the core software as authorized by the software developer/vendor. Access to a certain functionality or set of functionalities by the customer developed software is obtained by adapting the customer developed software to submit a key, provided by the software developer/vendor, to the core software through, for example, an application programming interface (API) of the core software.

Abstract: Disclosed herein are a method and system for sharing a single GPIO line of an integrated circuit (IC) between at least two circuit components connected concurrently, wherein at least one of the circuit components is to provide input via the GPIO line and at least one circuit component is to receive output via the GPIO line. The input and output can be provided at separate times with the status of the GPIO line changing accordingly or, provided that the input is provided at a lower frequency relative to the switching frequency of the GPIO line, an input to the IC can be provided concurrent with an output from the IC since the low frequency input typically persists until an input cycle of the GPIO line. The present invention finds particular benefit when implemented to interface with GPIO lines of a microprocessor.

Abstract: A method and system for controlling access to various tiers of functionality of core software are provided. A software developer/vendor can develop a single version of software having one or more limited-access functionalities and provide the single version of the software to various types of customers. Each customer, using the single version of the core software, may develop additional software that utilizes one or more functionalities of the core software as authorized by the software developer/vendor. Access to a certain functionality or set of functionalities by the customer developed software is obtained by adapting the customer developed software to submit a key, provided by the software developer/vendor, to the core software through, for example, an application programming interface (API) of the core software.

Abstract: A modem is implemented as a virtual device driver with all processing handled by the host computer thus obviating the need for a stand alone processor for the modem. The modem virtual device driver ensures that the modem obtains adequate processing time regardless of other processes running on the host. By combining a port driver directly into the modem contact code, the need for a hardware UART with its attendant limitations is eliminated.

Abstract: DOS application programs are accommodated when using a controllerless modem by providing a virtual device driver. The virtual device driver emulates UART to UART communications and handles interrupts by the DOS applications and by a hardware port managed by the controllerless modem. In one implementation, the virtual device driver shares a communications interface in common with 32-bit applications. In a communication system environment, DOS applications can participate in modem to modem communications with remote DTEs and with other devices using the services of the virtual device driver.