gsm_print(3) on Linux
The text 769769b71d33, as Debian 5.0 (Lenny), Debian 4.0 (Etch), Debian 3.1 (Sarge), Debian 3.0 (Woody), Debian 2.2 (Potato), Debian 2.1 (Slink), Debian 2.0 (Hamm), Debian 1.3 (Bo) shipped it.
GSM 06.10 supplementary function for debugging