*COMDECK PBLMASK
         NAM   PBLMASK   LOAD MASK REGISTER 
         ENT   PBLMASK
         EXT   JKTMASK   SAVE AREA FOR MASK 
         EXT   LEVELNO   CURRENT SOFTWARE PRIORITY LEVEL
         EXT   QTOPSK    INTERRUPT COUNT
PBLMASK  NOP   0
         IIN   0         NON-INTERRUPTABLE PROGRAM
         LDQ   LEVELNO
         INQ   -1 
         LDA   JKTMASK,Q GET MASK VALUE 
         TRA   M         LOAD MASK REGISTER 
         LDA   QTOPSK    CHECK FOR INTERRUPT COUNT " 0
         SAN   1
         EIN   0
         JMP*  (PBLMASK)
         END
