- PSK31 is a seriously cool digital mode that has gained a lot of popularity since its inception. Created by Peter, G3PLX, this mode is ideal for keyboard to keyboard QSOs under high noise conditions, it only requires 100Hz separation, it's easy to use, and the software is free. It makes use of hardware that most hams have already, namely, a PC and a SoundBlaster compatible sound card.
- Hellschreiber describes a method of sending text by radio or telephone line that involves dividing each text character into little pieces and sending them digitally. Hellschreiber is a German name, meaning "bright writing", or "clear writing", and may be a pun on the name of the inventor, Rudolf Hell, who patented Hellschreiber in 1929. (Rudolf Hell, now in his 90s, lives in Bavaria). There are some excellent pages devoted to this method, and it's well worth checking out.
- Didn't know Morse was a digital mode? Well, it is! Morse is comprised of a series of "on"s and "off"s, which when assembled in the order they were transmitted, conveys information. Ergo, it's a digital mode. This is a page of links to some software for sending and receiving Morse, along with Morse tutorials.