ICANON            257 src/simh/linehistory.c   raw.c_lflag &= ~( ECHO | ICANON | IEXTEN | ISIG );
ICANON           2226 src/simh/sim_console.c runtty.c_lflag        = runtty.c_lflag & ~(ECHO | ICANON);     /* no echo or edit */