lock_iom         2538 src/dps8/dps8_cpu.c         lock_iom();
lock_iom         2570 src/dps8/dps8_cpu.c             lock_iom();
lock_iom         3689 src/dps8/dps8_iom.c     lock_iom();
lock_iom         2421 src/dps8/dps8_scu.c         lock_iom ();
lock_iom          129 src/dps8/threadz.h void lock_iom (void);