UNFIO_FMT

 NUMBER:  256

 ERROR CODE:  F

 MESSAGE TEXT:  unformatted I/O to unit open for formatted transfers

 EXPLANATION:  Attempted unformatted I/O to a unit where the OPEN
 statement indicated the file was formatted (FORM specifier).  Check
 that the correct unit (file) was specified.

 If FORM was not specified in the OPEN statement and the file should
 contain unformatted data, specify FORM='UNFORMATTED' in the OPEN
 statement.  Otherwise, if appropriate, use formatted I/O (such as
 list-directed or namelist I/O).