site_archiver@lists.apple.com Delivered-To: darwin-dev@lists.apple.com Godfrey On Apr 7, , at 18:21, Gregory Weston wrote: Godfrey van der Linden wrote: // At this point you have the port exclusively and non-preemtibly // so now is a good time to program up the modem or do any other // equipment initialisation you desire. Adding O_RDWR to the open() flags had no impact. _______________________________________________ Do not post admin requests to the list. They will be ignored. Darwin-dev mailing list (Darwin-dev@lists.apple.com) Help/Unsubscribe/Update your Subscription: http://lists.apple.com/mailman/options/darwin-dev/site_archiver%40lists.appl... Have you ever succeeded in talking to your serial device? Before going into arbitration just try to setup a simple program that sends an AT<CR> to the device and make sure you are getting an OK? If you aren't then you have other issues. BTW did you use O_NONBLOCK as one of the open flags or are you using the /dev/cu.??? device? Not to be terribly dense, but how? If I try to send an initialization string via write() I block forever. This email sent to site_archiver@lists.apple.com