prnstr macro msg
        mov ah, 09h
        lea dx, msg
        int 21h
        endm

data segment
        msg1 db "Enter string to be printed : $"
        msg2 db 0dh, 0ah, "I/O Error or Paper out...$"
        msg3 db 0ah, "Printing string...$"
        buf db 80
            db 0
            db 80 dup(' ')
data ends

code segment
        assume cs:code, ds:data, es:data
start :
        mov ax, data
        mov ds, ax
        mov es, ax

        prnstr msg1
        mov ah, 0ah
        lea dx, buf
        int 21h
        mov si, offset buf + 2
        mov ch, 00h
        mov cl, byte ptr [si-1]

        mov dx, 0000h
again :
        mov ah, 02h
        int 17h

        test ah, 00101001b
        jz cont
        prnstr msg2
        jmp again
cont :
        mov ah, 00h
        mov dx, 0000h
next :
        mov ah, 00h
        mov al, [si]
        int 17h
        inc si
        loop next

        mov ax, 4c00h
        int 21h
code ends
        end start