Interesting C question

Hello, all: I have discovered an interesting anomaly while finishing up the 2.2 version of the Altair32 Emulator (to be released this weekend, by the way). Maybe it's my lack of understanding of C or the service pack I applied to MSVC :-) Between version 2.0 and 2.1, BASIC 3.2 was broken -- it was hanging in a loop in the console input code waiting for the right status bits to be set by my port emulator code. While I was setting the right bits, the internal emulator variable wasn't reflecting the assignment. In the sio00h routine in the sio.c module, I declare a local-scope variable of type int that's not initialized... int sio00h (params...){ int nSioStatus ; ... stuff } When in the MSVC debugger, the undeclared variable has the value 0xcccccccc. OK. In the body of the routine, the variable can be set to three values using #defines from the header. For some reason, the variable is not being set to the #define value. As you trace execution, the variable to be returned by the routine remains 0xcccccccc after assignment: nSioStatus = SIO_WDB ; //#defines to 0x80 So, I initialized the variable to 0 and for good measure, returned the int as: return (nSioStatus & 0xff) ; In one of the top calling routines, it gets truncated to a BYTE-size (so to speak) anyway. So I figured that maybe there was a scoping problem but the nSioStatus variable is not used in any other module, nor is it declared extern or module global. The #define appears in multiple headers but are all defined to be the same value. Now, BASIC 3.2 it works but I can't really figure out why. Any thoughts?? Rich