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Xref: sserve comp.os.linux.development:18934 comp.os.linux.misc:29123 comp.os.386bsd.questions:14309 comp.os.386bsd.misc:4010 sci.electronics:83536 Newsgroups: comp.os.linux.development,comp.os.linux.misc,comp.os.386bsd.questions,comp.os.386bsd.misc,sci.electronics Path: sserve!newshost.anu.edu.au!harbinger.cc.monash.edu.au!msuinfo!agate!howland.reston.ans.net!cs.utexas.edu!utnut!utzoo!henry From: henry@zoo.toronto.edu (Henry Spencer) Subject: Re: 16550 detection Message-ID: <Cyws7o.JvG@zoo.toronto.edu> Date: Mon, 7 Nov 1994 17:50:11 GMT References: <TYTSO.94Nov1182557@dcl.mit.edu>> <MICHAELV.94Nov1215132@MindBender.HeadCandy.com> <Cynu1H.Is@pe1chl.ampr.org> Organization: U of Toronto Zoology Lines: 14 In article <Cynu1H.Is@pe1chl.ampr.org> pe1chl@rabo.nl writes: >I have extreme doubts about using an RS-232 interface at 230400 bps... >Even 115200 is already way above spec, and can be unreliable with >standard cables. Sorry, 115200 is well within spec. The limits on RS232 are set by the requirements that slew rate not exceed 30V/us and that transition times within the forbidden range (-3V to +3V) not exceed 0.04 bit times. At maximum slew rate, you cross the forbidden range in 200ns. If that is 0.04 bit times, the bit time is 5us, giving a maximum rate of 200kbps. 230400bps is outside the spec, but 115200 is not. -- Justice for groups that doesn't include justice | Henry Spencer for individuals is a mockery. | henry@zoo.toronto.edu