.\" Copyright 1996 Thomas Sailer (t.sailer@alumni.ethz.ch)
.\" May be distributed under the GNU General Public License
.\" "
.TH SMDIAG 8 "27 April 2008" "Smdiag 0.1" "Linux Programmer's Manual"
.SH NAME
smdiag \- Linux soundcard packet radio modem driver diagnostics utility
.SH SYNOPSIS
.B smdiag
.B "[\-i device]"
.B "[\-d display]"
.B "[ \-ce ]"

.SH DESCRIPTION
.B smdiag
may help to adjust the audio levels of the soundcard modem driver, as well
as to control the quality of the radio link. It may either display an
oscilloscope like view of the input signal, or display an eye diagram.
The display may be gated with DCD, i.e. only updated if the modem detects
a data carrier.

.SH OPTIONS
.B smdiag
accepts the following options:

.TP
.B \-i
The
.I device
argument specifies the soundcard modem device which should be configured or
interrogated.  It will usually have the following form:
.I sm[0-3].
.TP
.B \-d
sets the address of the X server to display the window.
.TP
.B \-h
display an overview of the available command line parameters and exit.
.TP
.B \-c
toggle the carrier gating of the display.
.TP
.B \-e
display an eye diagram (overlay of the synchronized demodulator output)
instead of an oscilloscope view of the input signal.

.SH KEYS
.TP
.B C
clears the window
.TP
.B D
toggles the DCD gating.
.TP
.B E
displays an eye diagram
.TP
.B I
displays the input signal
.TP
.B Q
quits
.I smdiag

.SH BUGS
.B smdiag
Reacts sluggishly to keypresses. The window size is fixed. For speed reasons,
two square root operations per sample are not implemented in the AFSK 1200
baud modes. The eye diagram for the AFSK 1200 baud mode is therefore
distorted.

.SH "SEE ALSO"
.BR smmixer " (8), " sethdlc " (8),"
linux/drivers/net/soundmodem.c

.SH AUTHOR
smdiag was written by Thomas Sailer (t.sailer@alumni.ethz.ch).