I can't see significant difference in overhead between say this and the elapsed timer example
correct there is not much overhead difference when pbp interrupts are used , main point was to show that time accuracy using time stamps is easy versus trying to fudge clock counts
so that elapsed_int could be used without modification and also to show that conversion to h:m:s is not too difficult

the main difference between asm and pbp interrupts is whats entailed in ReEnterPBP.bas code . its up to the user to determine if the application can tolerate the overhead or a more efficient method need be developed