Thank you buddy,

I see it all now, (some of it),

So once I've read the ECU and copied the ROM contents I have the Cal files (also known as binaries or firmware)...............Correct ?

The def files are the ones that make it easier on the numpty (me) yes ?

Would these def files have been used by Ford or whoever programmed their ECU's originally ?

If so I may have a back door

Cheers for now Dave