System and method for positional control device data source selection

Abstract

A technique for emulating a computer game port uses a memory manager software program to detect output instructions from a computer software program to the game port. In response to the detected output instruction, the memory manager diverts program operation to an interrupt routine wherein position data is read from a data frame and one or more game port delay times are calculated to correspond with the position of the selected positional control device. The delay times correspond with the delay times of a conventional analog joystick coupled to a conventional game port. The memory manager also detects input instructions from computer software program to the game port and diverts the computer software program to an interrupt servicing routine in which the emulated delay times are used to load a data register that is read by the computer software program. The data bits in the data register correspond to the delay time bits and are initially set to a first logic level during the delay time period, and reset after the expiration of the delay time period. In this manner, any positional control device can be used to provide position data to emulate a computer game port. The computer may also contain a plurality of positional control devices, each supplying its position data in a predetermined format to the data frame within the computer memory. A data selector indicates the source in the data frame of each direction of positional control device movement. In response to intercepted output instructions from the computer software program, the system reads position data from the user selected data source and calculates the emulated delay times accordingly.