linpsk(1) on Linux
The text 90bd07c8181b, as Debian 10 (Buster), Debian 9 (Stretch), Debian 8 (Jessie), Debian 7 (Wheezy), Debian 5.0 (Lenny), Debian 4.0 (Etch), Debian 3.1 (Sarge), Debian 3.0 (Woody) shipped it. The page shows this text now.
amateur radio PSK31/RTTY program via soundcard