*DECK     SSBCBW
          IDENT  SSBCBW 
          ENTRY  SSBCBW 
          TITLE  SSBCBW - CLEAR BIT IN WORD.
          COMMENT  CLEAR BIT IN WORD. 
 SSBCBW   SPACE  4,10 
***       SSBCBW - CLEAR BIT IN WORD. 
* 
*         S. H. FISCHER.     81/07/15.
          SPACE  4,10 
***       SSBCBW IS A ROUTINE TO EFFICIENTLY CLEAR A BIT IN A WORD TO 
*         THE RIGHT OF BIT 48. THE BIT NUMBER IS 1 FOR BIT 47, 2 FOR
*         BIT 46, ETC 
          SPACE  4,10 
***       SYMPL CALLING SEQUENCE. 
* 
*         SSBCBW( WORD,BITN)
* 
*                WORD = WORD TO CLEAR BIT IN. 
* 
*                BITN = BIT NUMBER TO CLEAR.
 CBW      SPACE  4,10 
 SSBCBW   EQ     *+1S17D
 CBWX     EQU    *
          SA3    A1+1        BIT NUMBER ADDRESS 
          SA2    X1          WORD 
          MX4    1
          SA3    X3          BIT NUMBER 
          SB7    X3-49       B7 = N - 49 = -( 49 - N )
          LX4    -B7         POSITION BIT 
          BX6    -X4*X2      CLEAR BIT
          SA6    X1 
          EQ     CBWX        RETURN 
          END