code segment
assume cs:code
main proc far
;
repeat:
call read
call crlf
call change
call crlf
jmp repeat
main endp
;
read proc near
mov bx, 0
newchar:
mov ah, 1
int 21h
sub al, 30h
jl exit
cmp al, 9d
jg exit
cbw
;
xchg ax, bx
mov cx, 10d
mul cx
xchg bx, ax
add bx, ax
jmp newchar
exit:
ret
read endp
;
change proc near
mov ch, 4
for:
mov cl, 4
rol bx, cl
mov al, bl
and al, 0fh
add al, 30h
cmp al, 3ah
jl print
add al, 07h
print:
mov dl, al
mov ah, 02h
int 21h
dec ch
jnz for
change endp
crlf proc near
mov dl, 0dh
mov ah, 2
int 21h
mov dl, 0ah
mov ah, 2
int 21h
ret
crlf endp
code ends
end main
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