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Xref: sserve comp.os.linux.development:18622 comp.os.linux.misc:28731 comp.os.386bsd.questions:14217 comp.os.386bsd.misc:3953 sci.electronics:83196 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!bunyip.cc.uq.oz.au!munnari.oz.au!spool.mu.edu!howland.reston.ans.net!ix.netcom.com!netcom.com!jonk From: jonk@netcom.com (Jonathan Dale Kirwan) Subject: Re: 16550 detection Message-ID: <jonkCypCzF.Jrq@netcom.com> Followup-To: comp.os.linux.development,comp.os.linux.misc,comp.os.386bsd.questions,comp.os.386bsd.misc,sci.electronics Organization: New World Computing Services X-Newsreader: TIN [version 1.2 PL1] References: <CMETZ.94Oct30051603@itchy.inner.net> <TYTSO.94Nov2113942@dcl.mit.edu> <jonkCyo2Au.239@netcom.com> <Cyp2ws.MIq@bonkers.taronga.com> Date: Thu, 3 Nov 1994 17:38:02 GMT Lines: 54 Peter da Silva (peter@bonkers.taronga.com) wrote: : In article <jonkCyo2Au.239@netcom.com>, : Jonathan Dale Kirwan <jonk@netcom.com> wrote: : >This means I must set the internal serial board (if using an external : >modem) at rates of 57.6k or better to keep up. It is hard to ask for : >common users to understand the need for 16550 chips (or CPU-based : >serial cards) in order to use a modem. Better for them to save the : >$10 to $15 extra charged for 16550-based boards and to spend it on : >a $75 14,400 bps internal modem. Even with a 16550, the 16 bytes : >that it buffers (even though it should interrupt in 8) only provides : >about 2 to 3 milliseconds of latency. The internal boards all provide : >enough buffer to get by, mostly. : From what you're saying it sounds like you're talking about a DOS/Windows : environment where 2-3 milliseconds latency is a big deal. If you'll take : a peek at the newsgroups line, you'll see that the discussion is crossposted : to (and started in) the 386BSD and Linux groups. Thanks for that correction. No, I did not understand the environment being discussed. I'd still suggest, though, that the software advantages of an internal modem remain. Those advantages may not be worth it, depending on point of view. : We've also had a lot worse luck getting internal modems that work worth a : damn. We used to have a bunch, I don't know what brands, but they've all : been replaced by Sportsters by now, because they just wouldn't sustain a : connection (or in some cases connect at all). Those that I have tested in the last year or so have been quite successful under DOS and Windows. It may be due to the fact that manufacturers of these modems spend the time to develop (or hire the development of) their own DOS and/or Windows drivers but do not do so for 386BSD or Linux. The "standard" drivers available in those environments may _require_ you to handle the problems the way you have found to be so successful. I cannot say. : Finally, external modems make great external fuses for minor power surges : over the phone line. I'd rather not have that plugged into my bus. In the US, at least, phone lines theoretically have to have adequate arresters before the line enters the house or building, but I take your point. For my clients, at least, it is not an important issue and does not factor in the solution. In 20 years of my experience so far with modems, one has not "been the fuse" that saved a single computer. PCs are cheap to replace (from my perspective) and I hope adequate backups are available to get things working again, if such eventuality should occur. But I've not seen it or heard of a specific example that actually did occur. I don't doubt that such a situation has occured, but I just don't hold my breath waiting. There are other forms of insurance more worthy of purchase, I think. Jon K