.model small
.data
m1 db 'type a character :','$'
m2 db 0ah,0dh,'the ascii code of '
c1 db ?,' in binary is :','$'
m3 db 0ah,0dh,'the number of 1 bit is '
c2 db ?,'$'
.code
main proc
mov ax,@data
;initialize ds

mov ds,ax
mov ah,9
;prompt the user
lea dx,m1
int 21h
;-------------
mov ah,1
;read character
int 21h
mov bl,al
mov c1,al
;store character

mov ah,9

lea dx,m2
int 21h

mov bh,0
;counter for one’s
mov cx,8
mov ah,2
l1: shl bl,1
;display content of bl

jc l2
mov dl,'0'
int 21h
jmp l4
l2: mov dl,'1'
int 21h
inc bh
;count number of one’s
l4: loop l1
add bh,30h
;convert to char.
mov c2,bh
mov ah,9
;display number of one’s

lea dx,m3
int 21h

mov ah,4ch
;return to dos
int 21h
main endp
end main