Ruben J=F6nsson wrote: > = > Also remember to not store any intermediate results in another register (= even = > W) and then write it back to the shadow register. Only use atomic, non = > interruptable methods (single instructions or disable interrupts) when = > manipulating the bits in the (global) shadow register. Another part of this low end with which I'm not familiar.. If interrupts are disabled when one *would have* been delivered, is it lost? Or delivered if/when interrupts are re-enabled (to some stack-limited number, no doubt)? -- = #ken P-)} Ken Coar, Sanagendamgagwedweinini http://Ken.Coar.Org/ Author, developer, opinionist http://Apache-Server.Com/ "Millennium hand and shrimp!" -- = http://www.piclist.com PIC/SX FAQ & list archive View/change your membership options at http://mailman.mit.edu/mailman/listinfo/piclist