ASCII to binary & how many 1 bits in Assembly language

include "emu8086.inc"
.model small
.stack 100h
.code
main proc
    print "Enter a character: "
    mov ah,1
    int 21h
    mov bl,0h
    printn
    print "Here the ASCII to Binary is: "
    mov cl,0
    top:
    cmp cl,8
    je exit
    Rol al,1
    jnc zero
    jc one
    jmp exit

    zero:
    print "0"
    inc cl
    jmp top

    one:
    print "1"
    inc cl
    inc bl
    jmp top

    exit:
    printn
    print "Here the 1-bits has: "
    add bl,30h
    mov ah,2
    mov dl,bl
    int 21h