System timers set by a central processing unit (CPU) provide a variable wait time functionally adapted and related to peripheral device availability. Wait time is iteratively and dynamically adjusted to more closely match peripheral performance to the system, thereby reducing CPU load and enhancing data...http://www.google.co.uk/patents/US5566351?utm_source=gb-gplus-sharePatent US5566351 - Adaptive polling system by generating sequence of polling signals whose magnitudes are functionally related to the occurrence of the busy signal
