DATAW1 DW              97F4H
COUNT2       DB              ?
;            ...
             SUB     AL,AL         ;clear AL to keep the number of 1s in BCD
             MOV     DL,16         ;rotate total of 16 times
             MOV     BX,DATAW1     ;move the operand to BX
 GAIN:       ROL     BX,1          ;rotate it once
             JNC     NEXT          ;check for 1.   If CF=0 then jump
             ADD     AL,1          ;if CF=1 then add one to count
             DAA                   ;adjust the count for BCD 
 EXT:        DEC     DL            ;go through this 16 times
             JNZ     AGAIN         ;if not finished go back
             MOV     COUNT2,AL     ;save the number of 1s in COUNT2