Inventors:
G. Byron Sands - Spring TX
Peter J. Brown - Houston TX
Don A. Dykes - Houston TX
Andrew L. Love - Spring TX
Kevin W. Eyres - Tomball TX
Assignee:
Compaq Computer Corporation - Houston TX
International Classification:
G06F 300, G06F 1300, H04B 138, H04L 516
Abstract:
A computer system implements a standard modem without the use of a microcontroller. Instead, a digital signal processor is provided on an expansion card, but with direct links to the computer system itself. The code usually implemented in the microcontroller is instead implemented as a virtual modem controller to be called by the operating system of the computer itself. Further, this virtual modem controller includes a virtualized UART, that appears to the operating system software as a hardware UART, with entry points for calls to replace input/output instructions. In this way, standard device driver code written to execute input/output operations is easily converted to operate with the "virtualized" UART.