Fl-digi: digital data over voice channels
fl-digi: one of several free programs that make up the Narrow-Band Emergency Messaging System software suite.
fl-digi allows a Ham Operator with only a laptop and a "handie-talkie" to send and receive complex text documents over voice channels, including many voice repeaters.
in the Seattle area, there is a "Digital Net" every Monday night at 8 PM, on the Columbia Tower repeater, 444.550 MHz, positive offset, tone is 141.3 Hertz.
In just a few minutes on this Voice Plus Digital Net, the attendees will help even a complete beginner find the software, install it on their own computer, and start receiving messages sent by other operators.
It's far easier than you think! You might even send some messages on your very first attempts.
Here is the download page at SourceForge.net for fl-digi and its accessory programs