I'm kind of lost on how to use this feature... I am using the PIC18F67J60 chip, and the Microchip C 18 compiler. I generate the SQTP file, and load it, and can see the retlw lines at the program memory location I said to put it... And I've read all the documentation on this and am left clueless on a couple things... Where should I put this in my program memory? What I did is find the last four memory locations in my program memory and set the SQTP to use those (I chose these to make sure that in my normal code never tries to overwrite this location). Is that the right thing to do? Then here is my simple function to access the first byte of my SQTP data stored in program memory: int SQTPSerial; static void getSQTPSerial(void){ _asm call 0x1FFEE,1 movwf SQTPSerial,1 _endasm } PROGRAM MEMORY at location 0x1FFEE 65528 1FFEE 0C0A RETLW 0xa And my code goes bezerk here, it seems like I've corrupted some register at this point. So do I need to back up my w register before I start in there? Or can I do a call straight to that memory location or do I need to do something special to access that range in memory? Or is there some C 18 code somewhere that someone knows of I can use as a reference? Thanks, Rico Zinn -- http://www.piclist.com PIC/SX FAQ & list archive View/change your membership options at http://mailman.mit.edu/mailman/listinfo/piclist