Return to BSD News archive
Newsgroups: comp.unix.bsd Path: sserve!manuel.anu.edu.au!munnari.oz.au!spool.mu.edu!agate!stanford.edu!kronos.arc.nasa.gov!iscnvx!netcomsv!netcom.com!abe From: abe@netcom.com (David Abercrombie) Subject: Re: How do I enable COM3 and COM4? Message-ID: <1992Oct20.143735.1331@netcom.com> Organization: Netcom - Online Communication Services (408 241-9760 guest) References: <1992Oct15.162922.24566@fcom.cc.utah.edu> <1992Oct19.032151.29724@cs.cornell.edu> <veit.719567281@du9ds3> Date: Tue, 20 Oct 1992 14:37:35 GMT Lines: 41 In article <veit.719567281@du9ds3> veit@du9ds3.uni-duisburg.de writes: >In <1992Oct19.032151.29724@cs.cornell.edu> cchase@cs.cornell.edu (Craig Chase) writes: > >>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 > >>p.s. mknod /dev/com2 c 8 2 ; mknod /dev/com3 c 8 3 > >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" I just got an STB 4-COM serial card with the equivalent of four 16550A UARTS on it. It has 40 jumpers that allow you to choose from a list of eight different i/o port addresses and eight different IRQ lines for any of the four ports. I can easily find unused IRQ lines on my system so that I can have four ports working. I just got this card and am having some minor difficulties, but will let you all know more details once I have had a chance to really test it. -- Dave Abercrombie lyra!abe@infoserv.com Oakland, CA -- or -- (510) 652-7131 abe@netcom.com