Path: utzoo!attcan!utgpu!jarvis.csri.toronto.edu!mailrus!cs.utexas.edu!ginosko!brutus.cs.uiuc.edu!apple!bbn!news From: news@bbn.COM (News system owner ID) Newsgroups: comp.unix.wizards Subject: Re: Real Time UNIX (was: Re: How do you tell a wizard?) Message-ID: <47024@bbn.COM> Date: 17 Oct 89 15:55:08 GMT References: <21153@adm.BRL.MIL> <17150@rpp386.cactus.org> Reply-To: pplacewa@antares.bbn.com (Paul W. Placeway) Organization: Bolt Beranek and Newman Inc., Cambridge MA Lines: 34 jfh@rpp386.cactus.org (John F. Haugh II) writes: < It is very worth pointing out that Plexus used UNIX kernels on < their serial I/O processor cards. I don't know if anyone from < Plexus [ is there still a Plexus??? ] is listening and has any < info on that implementation. Oooooo Ick! That must have been a mistake. Since I'm fairly new (I started by playing with 4.1 BSD), I'll ask a few of the old(er)-timers out there: has there ever been a UNIX serial driver that worked right? What I (personally) want to see is something that will do some version of the normal cooked vs. not processing (pref. designed to be configurable, like Sys V's, rather than hacked, like Berkeley's), will actually _do_ hardware flow control, correct modem control, sync, and async if the hardware can (without reconfiguring the kernal to do so), and is eficient enough to handle sustained input at 38.4Kbps (if the system has a DMA serial board). It should also handle non-blocking I/O, and deliver SIGIOs, if asked. And the user should be able to tell it to allocate bigger, smaller, default, etc. amounts of input buffer storage. Yes, the 38.4Kbps and flow control, etc. are highly dependant on the hardware, but in the "newer" UNIXen, on machines with perfectly capable hardware, getting this all to work for a user-level process is like pulling teeth (or just plain imposible). Show me all this, and I will show you a happy serial I/O hack indeed. The current ones are set up for the special case of talking to an ordinary terminal. Unfortunately, there are much more things that can be done with a serial line... -- Paul Placeway