.data
    string db 80 dup(" ")   ; Hold up to 80 characters
    str_length dw -1    ; Must start on -1 as return key is a character
    char db ?

proc readString
    push ax bx
    clc
    mov bx, OFFSET string
next_char:
    call readChar
    jc done
    mov al, char
    mov [bx],al
    inc bx
    jmp next_char
done:
    pop bx ax
ret
endp readString

proc readChar
    push ax

    mov ah,1
    INT 21H
    mov char,al

    cmp char, 13    ; IS IT RETURN CHARACTER??
    jnz done2
    stc     ; Set the Carry Flag

done2:
    inc str_length   ; Keep track of how many characters are entered
    pop ax
ret
endp readChar