BLOCK DATA 
 
      INTEGER  PSTACK (12) 
      INTEGER  PX 
      INTEGER  PEND 
      COMMON   /PPCOM/  PSTACK 
      COMMON   /PPCOM/  PX 
      COMMON   /PPCOM/  PEND 
      DATA  PX    /1/ 
      DATA  PEND  /10/ 
      END