The .ED directive will end the dummy mode that was started by the .DU directive.
In Version 3 of the SB-Assembler this directive will perform a boundary sync.
No error is reported if the dummy mode was not started when the .ED directive is encountered. In that case the .ED directive will simply be ignored.
Everything on the source line following the .ED directive will be treated as comment.
The SB-Assembler will not warn you if the program ends when no .ED directive ended an active dummy mode. The dummy mode can span across multiple include files.