> For the complete documentation index, see [llms.txt](https://cajac.gitbook.io/ctf-notes/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://cajac.gitbook.io/ctf-notes/misc/steganography/minimodem.md).

# Minimodem

*Minimodem* is a command-line program which decodes (or generates) audio modem tones at any specified baud rate, using various framing protocols. It acts a general-purpose software FSK modem, and includes support for various standard FSK protocols such as Bell103, Bell202, RTTY, TTY/TDD, NOAA SAME, and Caller-ID.

*Minimodem* can play and capture audio modem tones in real-time via the system audio device, or in batched mode via audio files.

*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.

## Installation

Install with

```bash
sudo apt-get install minimodem
```

## Usage

```bash
┌──(kali㉿kali)-[/mnt/…/Huntress_CTF/Huntress_CTF_2024/Miscellaneous/1200_Transmissions]
└─$ minimodem -r -f transmissions.wav 1200
### CARRIER 1200 @ 1200.0 Hz ###
Greetings, Professor Falken. 

Would you like to play a game? 

flag{f28d133e7174c412c1e39b4a84158fa3}

Thanks for playing the Huntress CTF!

```

## Resources

Homepage: <http://www.whence.com/minimodem/>