Jumps to any location in a file. If you use “E” as the second parameter, Jump will seek to the end of the file.

NOTE: If the file is opened for writing, the Jump command will automatically extend the file if addr specified is larger than the file size. This is useful for pre-allocating a file to reduce delays during writing.

IMPORTANT: If the file is extended, the data beyond the end of the file is undefined, so care must be taken to ensure your data is terminated properly.

You can use this command along with the Truncate command to pre-allocate (for faster writes) then truncate the file.


J fh addr|E


  • fh is a file handle (1 - 4). Use the Free Handle command to get a free file handle.
  • addr is the position to which you want to jump/seek.
  • E can be used to jump to the end of the file.

Response Format

EnnAn error occurred


To jump to byte position 2000 in file handle 1:

J 1 2000

To jump to the end of file handle 2:

J E 2