I need to have an internal bootloader in my Dallas 520 that can reprogram my external flash, and contain functions the external program can use, as these functions need to use ports P0 and P2 (precluding there execution from external code space. The programs are in C. I'm thinking of placing the external code in a space starting around 0x1000, allowing the chip to access both internal and external code space as needed. I'm shy on assembly experience, but I figure I can use embedded assembly as needed. I downloaded the bootloader example, but it won't load in uVision2. There are references to a jump table in the bootloader example, but it's not clear what this is. Also, how would this affect an ISR in the external code? Can anybody help? Thanks, Larry Koepke.