.
.         OPERATION ROADBLOCK
.
.         CONTROL GETS HERE WHEN AN OPERATION IS DISCOVERED TO
.         REFERENCE A ROADBLOCKED FILE.  THIS ROUTINE WILL FLAG
.         THE OPERATION AS SKIPPED, AND ERROR, ROADBLOCKING ALL
.         FILES USED IN THIS OPERATION.  THIS IMPLEMENTS THE
.         'CASCADE ROADBLOCK', AN APPLICATION OF THE DOMINO
.         THEORY TO SYSTEMS PROGRAMMING.
.
.
.         (C)  Copyright 1972-1978  John Walker
.
.         This software is in the public domain
.
          AXR$
          DEFUNCT$
          FANG
          PURE      CODE
.
ROADBLOCK* LX       X5,CDIMG,X8         LOAD IMAGE BUFFER ADDRESS
          R$DIT     .                   INITIALISE THE EDITOR
          JDEM      DRBM                DEMAND FORMAT LISTING ?
          E$MSG     SKEM                NO.  EDIT SKIPPED FLAG
          LMJ       X6,ESN              EDIT STATEMENT NUMBER
          E$COL     24                  TAB TO TEXT COLUMN
DAXBR     E$COPY    80,IMIMG,X5,U       COPY THE IMAGE
          R$PRTX    1                   PRINT THE LINE
          ZAP       .                   MARK THIS COMMAND AS HAVING ERRORED
          COMPLETE  .                   TERMINATE COMMAND PROCESSING
.
DRBM      LMJ       X6,ESN              EDIT STATEMENT NUMBER
          E$MSG     ABBY                EDIT SKIPPED FLAG
          J         DAXBR               GO AND COPY IMAGE
.
          PURE      DATA
SKEM      '*SKIPPED* !'
ABBY      ' *SKIP* !'
          END