the trouble was not in a typo. The Keil's has a twisted approach to the pointers' wraparound, but still it SHOULD work. I DO understand how it IS MEANT to work, I don't understand why it is NOT working.

I will join you in asking Pathipati to post what he finds as he grows his reduced code back to the original full code.

You STILL want to know why it is impossible to catch bugs in convoluted code?

let us take the example that the mistake in the code is to make the execution of xxx conditional.

this
if (...)
{
xxx;
}
makes it CRYSTAL CLEAR that xxx is only exceuted when a condition exist

this (as far as the compiler is concerned the very same as above)
if (...)
xxx;
makes anybody but the eagle-eyed easily miss that xxx exceuted conditionally.

Let us not get into discussing the more horrific convulsions - excuse me convolutions that the "real C" promoters come up with.

Also, the "shortcomings of C" have been discussed recently in another thread, this is not an attempt to reopen it.

Erik

Jan: I know you are going to say "this can not happen in assembler", it can!