hi, i have a question about the ioctl() api for tty.
the manpage indicates states called:

                 TIOCM_ST   Secondary Transmit.
                 TIOCM_SR   Secondary Receive.

these appear on a cable DB25 to connect terminals, but i'd like
to know how are they defined on a DB9 cable? are they simply
TX/RX?

thank you.

julien.