Computer with program tracing facility

Claim 1

In a computer including a program counter, a memory, an instruction register, and a comparator responsive to machine conditions to determine whether a branch is to be taken, means to record the branches taken during the execution of a program, comprising a branch record flip-flop, a branch address counter for providing successive addresses of an area in memory, means controlled by program to set the branch record flip-flop, and load a beginning memory address in the branch address counter, and means operative when a branch instruction is present in said instruction register, and said comparator determines that the branch is to be taken, to transfer the contents of the program counter to the location in the memory determined by the address in said branch address counter, and to increment the branch address counter, whereby said area in memory accumulates the addresses of all branch instructions which result in a branch path being taken.