Yes Hans,

I did use some strong adjectives to drive in the basic idea to keep any ISR short and sweet.

And giving the freedom of,

clr ea
;do sensitive stuff here
setb ea

has its downsides - particularly when someone new to timing issues does the coding. He ends up writing ISRs that look like main line code.

In any case one has his hands full in contending with the varioues levels of interrupts and thier priorities. And in such a situation if you end up coding such that the same source cuts in before the previous instance is over - then there is a problem.

Maybe I am not communicating what I think I should!

Raghu