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Path: sserve!manuel.anu.edu.au!munnari.oz.au!network.ucsd.edu!swrinde!cs.utexas.edu!uunet!mcsun!Germany.EU.net!unidui!du9ds3!veit From: veit@du9ds3.uni-duisburg.de (Holger Veit) Newsgroups: comp.unix.bsd Subject: Re: How do I enable COM3 and COM4? Date: 20 Oct 92 07:48:01 GMT Organization: Uni-Duisburg FB9 Datenverarbeitung Lines: 46 Message-ID: <veit.719567281@du9ds3> References: <1992Oct15.014800.729@skitzo.dseg.ti.com> <1992Oct15.162922.24566@fcom.cc.utah.edu> <1992Oct19.032151.29724@cs.cornell.edu> Reply-To: veit@du9ds3.uni-duisburg.de NNTP-Posting-Host: du9ds3.uni-duisburg.de In <1992Oct19.032151.29724@cs.cornell.edu> cchase@cs.cornell.edu (Craig Chase) writes: >In article <1992Oct15.162922.24566@fcom.cc.utah.edu> terry@cs.weber.edu (A Wizard of Earth C) writes: >>In article <1992Oct15.014800.729@skitzo.dseg.ti.com> dittman@skitzo.dseg.ti.com (Eric Dittman) writes: >>>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 >Craig >p.s. mknod /dev/com2 c 8 2 ; mknod /dev/com3 c 8 3 >-- >"They [La Prensa] accused us of suppressing freedom of > expression. This was a lie and we could not let them > publish it." > - Nelba Blandon, Interior Ministry Director of Censorship, quoted in This is the obvious "solution", but will cause really dirty problems, provided you do not remove the lines for com1 and com2 (or com0/com1, depending how they are called). Usually they occupy the irq3 and irq4 lines. So you get an interrupt clash for the serial lines, with the effect that data may get lost in the situation where two ports on the same irq call for service. Don't use the above patch without modifying the com driver irq service to take care for these multiple events, even if anyone claims that "this works for me". In real situations, it will fail miserably. Holger -- | | / Dr. Holger Veit | INTERNET: veit@du9ds3.uni-duisburg.de |__| / University of Duisburg | "XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX | | / Dept. of Electr. Eng. | Sorry, the above really good fortune has | |/ Inst. f. Dataprocessing | been CENSORED because of obscenity"