Thank you guys for your explanation. From what I understand on this thread, the header of the firmware is 0x400 long. A page can be up to 0x800: ``` int size_

Thank you guys for your explanation. From what I understand on this thread, the header of the firmware is 0x400 long. A page can be up to 0x800: ``` int size_to_write = Size > 0x800 ? 0x800 : Size; ``` So it would appear the firmware has a header of 0x400 which is buffered during upload but discarded if the firmware fails the checksum at the end of the upload.