REALTIME COMPUTER OPERATION

In realtime systems which are controlled by digital computers, information is updated at prescribed time intervals regardless of whether or not there have been changes in the input values. This specification discloses a system for comparing the new values with the previous values for the same quantities and for reducing or eliminating computations performed by the computer when the values have not changed more than the prescribed amount. A digital comparator compares the old value from memory with the new value being transmitted to memory. When the difference between the two is within a prescribed amount, the output of the comparator signals the computer to ignore that computation and proceed to the next step.