Marvin Zelkowitz

This note is an extension of the ideas expressed by Morgan [1]. He suggests a new form of interrupt which he proposes to use to control the execution of a program, in his case a file management system called DPL [2]. Simply stated, he has attached to every subroutine a Boolean expression which, if true, would cause that subroutine to be executed. Since his implementation is via software, a relatively time-consuming check must be made whenever some condition in the program changes (e.g. some variable has a value changed). A rather simple hardware addition to existing machines can easily implement this interrupt. The following is such a proposal.