Video game card having interrupt resistant behavior

摘要

A high precision game card generates a digital signal corresponding to each analog input signal from a controller. Each digital signal has a digital value proportional to the number of "reads" to the game card by a computer microprocessor. The digital signals can therefore be read by the computer without disabling the computer interrupts. The game card converts the analog input signals to a corresponding numeric value and this value is compared with an output of a counter which counts the number of "reads" by the computer. If the number of "reads" equals or exceeds the numeric representation, the corresponding digital signal is deasserted. The digital signals are initially asserted responsive to a "write" to the game card by the computer microprocessor. Alternatively, the numeric representations can be provided directly to the computer over the computer data bus. This embodiment provides all of the numeric representations over a single address.