extern int ser_base_setstopbits (struct serial *scb, int rate);
extern int ser_base_drain_output (struct serial *scb);
-extern int ser_base_write (struct serial *scb, const char *str, int len);
+extern int ser_base_write (struct serial *scb, const void *buf, size_t count);
extern void ser_base_async (struct serial *scb, int async_p);
extern int ser_base_readchar (struct serial *scb, int timeout);