Infinite loop

If you wish to execute a loop until some external terminating event takes place (for example, an end of file), then you may do so by specifying the INF positional parameter.

Thus, coding:

        DO  INF
          Code for F
        ENDDO

produces:

        DO  INF
#@LB2     DC    0H
          Code for F
        ENDDO
          BC    15,#@LB2

In order to generate an infinite loop, no FROM, WHILE, or UNTIL keywords can be present. TO and BY keywords, if present, are ignored.