minimodem − software audio Bell-type or RTTY FSK modem
minimodem
--tx [options] {baudmode}
minimodem --rx [options] {baudmode}
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.
−t, −−tx, −−transmit, −−write
transmit mode: generate audio tones
−r, −−rx, −−receive, −−read
receive mode: decode audio tones
−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
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 |
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|
300 |
: Bell103 300 bps −−ascii |
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|
rtty |
: RTTY 45.45 bps −−baudot −−txstopbits 1.5 |
{any floating point value N}
: Bell-like N bps −−ascii
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).
minimodem does not decode AX.25 framed packets.
minimodem does not support modem control ("AT") commands, nor does it produce DTMF telephone dialing tones.
This page documents minimodem version 0.8.1. The latest version is available at <http://www.whence.com/minimodem>.
minimodem was written by Kamal Mostafa <kamal@whence.com>.
Copyright
© 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.