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Newsgroups: comp.unix.bsd Path: sserve!manuel.anu.edu.au!munnari.oz.au!sgiblab!darwin.sura.net!udel!sbcs.sunysb.edu!sbcs!stark From: stark@cs.sunysb.edu (Gene Stark) Subject: Re: How do I enable COM3 and COM4? In-Reply-To: cchase@cs.cornell.edu's message of Mon, 19 Oct 1992 03: 21:51 GMT Message-ID: <STARK.92Oct21200502@sbstark.cs.sunysb.edu> Sender: usenet@sbcs.sunysb.edu (Usenet poster) Nntp-Posting-Host: sbstark Organization: SUNY at Stony Brook Computer Science Dept. References: <1992Oct15.014800.729@skitzo.dseg.ti.com> <1992Oct15.162922.24566@fcom.cc.utah.edu> <1992Oct19.032151.29724@cs.cornell.edu> Date: Thu, 22 Oct 1992 01:05:02 GMT Lines: 27 >>>How do I enable COM3 and COM4 in the binary distribution of 386BSD 0.1 >>>from agate.berkeley.edu? Or do I have to do this from the source? >> >>You have to modify the configuration file, config, and rebuild the kernel. >>Amacio Hasty (I believe) has put together a "minimum required sources" >>tar archive on agate and elsewhere for the rebuilding of kernels for those >>with only 40Meg of disk. >> >> >You might also want to edit isa.h to add >#define IO_COM4 0x2e8 >#define IO_COM3 0x3e8 > >and then use in the config file >device com2 at isa? port "IO_COM3" tty irq 4 vector comintr >device com3 at isa? port "IO_COM4" tty irq 3 vector comintr Is this just folk wisdom, or has anyone actually tried this? I did, and once interrupts were enabled for COM3 and COM4, I failed to get any interrupts at all, as if the new COM ports were driving the IRQ line all the time. Also, I didn't see any mechanism in the interrupt/driver code whereby comintr() could receive the proper unit number when COM3 and COM4 interrupted. That is, the unit number was derived directly from the interrupt vector location. I was prepared to modify the driver to poll to determine which port(s) required service, but as I said, I didn't get any interrupts. - Gene Stark