If so what modifiers/specifiers do I need to be
> using if the calling function and the handler are in 2 different physical
> files?
Hi, your want use 2 separate linked files? You can use 'mailbox': cell / register with rigid address, I set one over .asm command. Of course you must see overlapping with linker if cell or translator if register. You will have more little problems without any call in handler but use semaphore. Victor