;From the data segment:
DATA1        DB      97H
COUNT        DB      ?
 From the code segment:
             SUB     BL,BL           ;clear BL to keep the number of 1s
             MOV     DL,8            ;rotate total of 8 times
             MOV     AL,DATA1
AGAIN:       ROL     AL,1            ;rotate it once
             JNC     NEXT            ;check for 1
             INC     BL              ;if CF=1 then add one to count
NEXT:        DEC     DL              ;go through this 8 times
             JNZ     AGAIN           ;if not finished go back
             MOV     COUNT,BL        ;save the number of 1s