First excuses if someone if someone think that i want to insut him. I'm sorry.

I conected the LCD to the bus like other bus device without any pullup resistor and works fine.

the last post is becase i'm surprised by the mov a,#"a"
...
mov a,#"b"
...

An other way to do is the famous "print" function

lcall print
db "Hola a todos",0
...


print:
pop dpl
pop dph
loop:
clr a
movc a,@a+dptr
jz end
lcall (your move byte to lcd)
inc dptr
sjmp loop
end:
push dpl
push dph
ret

(note: I'm not sure of the order of pushes and pops)

Have a nice day too. No war!!

Félix