RTTY (Radio TeleType is still a popular mode with a devoted following and extremely helpful community willing to help get newcomers involved.

RTTY using a computer, Purists like K6YIC use mechanical teletype machines in this mode

WIKIpedia definition: What is RTTY radio? RTTY Radio TeleTYpe (Also known as Baudot or ITA2) uses the Baudot 5-bit alphabet with FSK Frequency-Shift Keying to send text messages over the shortwave. This mode is gradually dying out in favor of more robust modes like PSK31 in the amateur service. Uses the ITA-2 alphabet (Commonly known as Baudot, derived from the Murray code)

ARRL description: RTTY (radio teletype) is the original keyboard to keyboard mode, based on the 5-bit Baudot code, began with mechanical Teletypes as mentioned above.  It is still a popular communications mode, but now uses PCs for coding and decoding, using 170 Hz frequency shift keying at a 45.45 baud rate — 60 words per minute.

Daniel Jones webpage K6YIC.com, Dan has presented to several Amateur Radio Clubs (including TCARA) about RTTY and his restored classic teletype machines that he uses On The Air.

Radio Teletype (RTTY) – Signal Identification Wiki (sigidwiki.com)

A RTTY Tutorial for beginners – IW5EDI Simone – Ham-Radio

RTTY Software : RTTY programs, software for ham radio RTTY emission mode (dxzone.com) FLDIGI is typically the recommended choice for computer based RTTY