With the .LM directive you can set the width of the left margin of the list file. This is useful if you plan to send the listing to a printer.
Version 3 doesn't have any of the page formatting directives because they have become fairly obsolete nowadays. Therefore the .LM directive is also scrapped from the list of directives.
Usually the lines of a list file begin in the left most column.
With the .LM directive you can let each line begin with a number of spaces to create a left margin.
The number of spaces used as a margin is determined by the expression that follows the .LM directive.
The expression may have a value in the range from 0 to 16.
The setting of the left margin has no effect if the listing is sent to the screen.
The .LM directive will only be evaluated during pass 2 of the assembly process. Any errors in the parameter will not be detected before pass 2.