may be about output port setting(may be I didn t have much time to investigate your code but wish this would be useful to you).Have you already configure port before moving data through them?

By the way you d better chage your location for application. Because they may overlap with interrupt vector.
All would be conclued like this.

.org 0000H
reset: jmp init

.org so far away from interrupt vector
call port_init
\
your app

best regards