MINIMODEM(1) General Commands Manual MINIMODEM(1)
NAME
minimodem - software audio Bell-type or RTTY FSK modem
SYNOPSIS
minimodem --tx [options] {baudmode}
minimodem --rx [options] {baudmode}
DESCRIPTION
minimodem is a command-line program which generates (or decodes) audio modem tones at any specified baud rate, emulating an old Bell-type
or radio-teletype FSK modem. The tones can be played to (or recorded from) the PulseAudio system or to an audio file.
minimodem can be used to transfer data between nearby computers using an audio cable (or just via sound waves), or between remote computers
using radio, telephone, or another audio communications medium.
TX
/RX MODE
-t, --tx, --transmit, --write
transmit mode: generate audio tones
-r, --rx, --receive, --read
receive mode: decode audio tones
OPTIONS
-a, --auto-carrier
automatically detect mark and space frequences from carrier
-c, --confidence threshold
set receive confidence threshold (0.0 to 1.0, default 0.6)
-8, --ascii
ASCII 8-N-1
-5, --baudot
Baudot 5-N-1.5
-f, --file filename.wav
encode or decode an audio file (extension sets audio format)
-b, --bandwidth {rx_bandwidth}
-M, --mark {mark_freq}
-S, --space {space_freq}
-T, --txstopbits {m.n}
-q, --quiet
Do not report CARRIER / NOCARRIER or signal analysis metrics.
-V, --version
print program version
{baudmode}
The required {baudmode} parameter may be any floating-point value to specify a baud rate, or the string "rtty". The {baudmode} also
implies certain other parameter defaults depending on the rate, including standard (or at least reasonable) default mark and space tone
frequencies.
1200 : Bell202 1200 bps --ascii
300 : Bell103 300 bps --ascii
rtty : RTTY 45.45 bps --baudot --txstopbits 1.5
{any floating point value N}
: Bell-like N bps --ascii
EXAMPLES
minimodem --tx 100
Transmit 100 baud tones from one computer ...
minimodem --rx 100
and receive 100 baud tones on another nearby computer.
minimodem --rx --auto-carrier rtty
Decode amateur radio RTTY signals (listen near 14.085 MHz).
minimodem --tx 0.5
Experiment with very low baud rates (works in noisy conditions).
minimodem --tx 12000
Experiment with very high baud rates works (works with audio files).
NOTES
minimodem does not decode AX.25 framed packets.
minimodem does not support modem control ("AT") commands, nor does it produce DTMF telephone dialing tones.
VERSION
This page documents minimodem version 0.8.1. The latest version is available at <http://www.whence.com/minimodem>.
AUTHOR
minimodem was written by Kamal Mostafa <kamal@whence.com>.
COPYRIGHT
Copyright (C) 2011 by Kamal Mostafa <kamal@whence.com>. License GPLv3+: GNU GPL version 3 or later <http://gnu.org/licenses/gpl.html>.
This is free software: you are free to change and redistribute it. There is NO WARRANTY, to the extent permitted by law.
July 15, 2011 MINIMODEM(1)