Can anyone explain why all the IPCxxx() calls on MPE/iX use a 32-bit integer descriptor, yet IO[DONT]WAIT returns a 16-bit integer? Okay, IO[DONT]WAIT may refer to files as well as socket descriptors, but is there any possibility that a socket descriptor could ever be larger than 32767? If not, why make them 32-bit instead of 16-bit? I seem to remember them as 16-bit back on MPE-V. Jim "just looking out for possible errors" Wowchuk