Linmodem contains an X11 interface which can be used to monitor themodem parameters. It is used for example in v34 testing (lm -m v34). TheX11 simulation works only in 16 bit mode. If you are interested byother screen depths, please implement them :-)The function keys are used to change the parameters which are dumpedon the screen:* for V34:F1 : dump the brut samples which enter into the modem (at 8000Hz). Ahamming windowed FFT is done to output the spectral power.F2 : dump the echo cancellor parameters (not implemented yet).F3 : dump the samples after frequency normalization & symbol timingrecovery. You have 3 samples per baud for V34. A hamming windowed FFTis done to output the spectral power.F4 : dump the equalizer filter in both time & frequency domains.F5 : dump the QAM points just after the equalizer and phaserecovery. This graphic can be used to monitor the overall modemquality.* for V21/V23 testsF1: same as V34F3: decision samples