okay - thanks just to be clear, just because my 2001 S3 AMK and 2003 TT BAM both had the same map arrangement from bin to XDF - this was just coincidence as they must have used the same part number, but you cannot put a differently organised bin file structure - I wasn't sure whether when the car "booted up" the ECU would start reading the file and know what goes where from some sort of file allocation table.
I do remember on AudiSportNet, when some people were testing putting their AMK and BAM maps onto different cheaper 1.8T ECU's from Passat's or similar to document which ECU's can or cannot be used - as long as immo defeated and original MAP available to flash over second hand ECU. it's weird as some extra settings I have looked up and used the memory addresses found on-line and they were correct.
no matter - it was just a question. thanks for the replies