In the Keil help section it seems to imply that each task name gets its own individual 16bit flag ie. as in os_evt_set (0x0004, id2); and os_evt_set (0x0004, id3); if so, how does os_evt_wait_or (0x0004, 0xffff); know which task's flag it belongs too? Or am I misinterpretting the help file. I seem to think that all tasks share a common 16bit flag and that the os_evt_wait_or and os_evt_wait_and are used to select which individual or group of flags is of interest. Can someone put me straight. Thanks.