lock_iom         1890 src/dps8/dps8_cpu.c         lock_iom();
lock_iom         1922 src/dps8/dps8_cpu.c             lock_iom();
lock_iom         3405 src/dps8/dps8_iom.c     lock_iom();
lock_iom         2278 src/dps8/dps8_scu.c         lock_iom ();
lock_iom          128 src/dps8/threadz.h void lock_iom (void);