SIGIOT            550 gc/os_dep.c    #	ifdef SIGIOT
SIGIOT            551 gc/os_dep.c    	    SIG_DEL(new_mask, SIGIOT);
SIGIOT            121 src/signal.c   #ifdef SIGIOT
SIGIOT            122 src/signal.c       SIGDEF(SIGIOT,  SIGDEF_ERROR),    /* IOT trap (4.2 BSD) */