Hi,
First, I don't understand why you shouldn't (can't) be able to use GOSUB inside or outside of a DT-INTS ISR as long as you RETURN (as you should with ANY GOSUB), anyone care to elaborate on the reason you say you should never do that? Yes, the stack is limited, so you need to makes sure it doesn't overflow if you happen to get an interrupt when you're already into x nested GOSUBS but as far as I can see it should work.

Hank, I'm not syaing I have a solution for you but is seems to me that your program can "fall thru" into the ISR by itself. It wakes up, DT-Ints trips and jumps to the ISR, the ISR runs and the then it returns to where it woke up, which is right before the ISR so the ISR runs again. It hits the @INT_RETURN (by the way, there seems to be a missing underscore in your code?) and it returns to "somewhere". I think you need a Goto Loop1 or whatever right after the DEBUG satement - but I just had a quick look at it so I may be missing something.

/Henrik.