*COMDECK PBAMASK
         NAM   PBAMASK   AND MASK REGISTER
         ENT   PBAMASK
         EXT   JKTMASK   SAVE AREA FOR CURRENT MASK 
         EXT   LEVELNO   CURRENT SOFTWARE PRIORITY LEVEL
         EXT   QTOPSK    INTERRUPT COUNT
PBAMASK  NOP   0
         IIN   0         NON-INTERRUPTABLE PROGRAM
         TRM   A         TRANSFER M TO A
         LDQ   LEVELNO
         INQ   -1 
         STA   JKTMASK,Q SAVE CURRENT MASK
         LDQ*  (PBAMASK)
         LDA   0,Q       GET NEW MASK 
         RAO*  PBAMASK
         LAM   M         AND NEW MASK WITH CURRENT MASK 
         LDA   QTOPSK    CHECK INTERRUPT COUNT " 0
         SAN   1
         EIN   0
         JMP*  (PBAMASK)
         END
