anchor.diff:  Immediate commands
   ------------------
   
  -Immediate commands are executed on the command line. They are not stored as part of the program. They have no line number. They are available only in "run" mode.
  +Immediate commands are executed on the command line.
  +They are not stored as part of the program.
  +They have no line number.
  +They are available only in "run" mode.
   
   NEW
   ~~~
  
positive.code: 
  The number of values in a READ statement do not have to match the number of values in DATA statements.
  The values defined in DATA statements are stored in a single list of use by all READ statements.
  You may READ in pairs and define ten values per DATA statement. You may READ ten items from DATA statements that contain one value each.
  
  READing more values than are specified by DATA statements, in total, will cause an error.
  
  BASIC keeps an internal pointer to the next data item. This pointer can be reset with the RESTORE statement.
  
  Reading from files
  ^^^^^^^^^^^^^^^^^^
  
negative.code: 
  	20 FILES "test.txt"
  
  File names must be enclosed in double-quotes.
  Files must exist at the start of the program, even when the file will be written.
  It is not possible for BASIC to create a file.
  
  