pprb
dummy = pia(this_port[i])->pprb; /* clear irq bit */
s->u.amiga.data = pia(p)->pprb;
pia(p)->pprb = s->u.amiga.data;
dummy = pia(p)->pprb; /* clears irq bit */
pia(p)->pprb = data;
return pia(p)->pprb;