Oracle: Reading fixed-field-length files with external tables

create table ext_table_fixed (
   field_1 char( 4),
   field_2 char(30)
)
organization external (
   type    oracle_loader
   default directory ext_dir
   access  parameters (
     records delimited by newline
     fields (
       field_1 position(1: 4) char( 4),
       field_2 position(5:30) char(30)
    )
  )
  location ('data.fld')
)
reject limit unlimited;

B000Albert
B001Basil
B002Caesar
B003Darius