From: jp Newsgroups: alt.folklore.computers Subject: Comm port speed folklore Date: Fri, 23 Jul 1999 21:12:37 -0700 Organization: Prodigy Internet http://www.prodigy.com Lines: 7 Message-ID: <37993D35.1BD9@spamcop.net> NNTP-Posting-Host: slip129-37-20-17.ga.us.ibm.net Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit X-Trace: newssvr04-int.news.prodigy.com 932790281 1500380 129.37.20.17 (24 Jul 1999 04:24:41 GMT) X-Complaints-To: abuse@prodigy.net NNTP-Posting-Date: 24 Jul 1999 04:24:41 GMT X-Mailer: Mozilla 3.0 (Win95; I) Path: chonsp.franklin.ch!pfaff.ethz.ch!news-zh.switch.ch!iol.ie!news-out.cwix.com!newsfeed.cwix.com!205.252.116.205!howland.erols.net!panix!cam-news-hub1.bbnplanet.com!news.gtei.net!newscon02!prodigy.com!not-for-mail I had noticed that the comm ports of my new computer at work were set at 9600. I reset them to the maximum speed. When I mentioned this to the tech, he said it didn't matter. The modem sets the speed and doesn't use the port speed. Is this true or folklore? ###### From: lucvdv@null.net (Luc Van der Veken) Newsgroups: alt.folklore.computers Subject: Re: Comm port speed folklore Organization: . Message-ID: <379fa511.1527216@news.pandora.be> References: <37993D35.1BD9@spamcop.net> X-Newsreader: Forte Agent 1.5/32.451 MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit Lines: 11 Date: Sat, 24 Jul 1999 11:37:49 GMT NNTP-Posting-Host: 212.123.10.187 X-Complaints-To: systemgroup@telenet-ops.be X-Trace: afrodite.telenet-ops.be 932816269 212.123.10.187 (Sat, 24 Jul 1999 13:37:49 MET DST) NNTP-Posting-Date: Sat, 24 Jul 1999 13:37:49 MET DST Path: chonsp.franklin.ch!pfaff.ethz.ch!news-zh.switch.ch!newsfeed-zh.ip-plus.net!news.ip-plus.net!News.Amsterdam.UnisourceCS!newshunter!cosy.sbg.ac.at!news-feed.inet.tele.dk!bofh.vszbr.cz!news.belnet.be!afrodite.telenet-ops.be!not-for-mail jp posted: > I had noticed that the comm ports of my new computer at work > were set at 9600. I reset them to the maximum speed. When > I mentioned this to the tech, he said it didn't matter. The > modem sets the speed and doesn't use the port speed. > > Is this true or folklore? It's true. The port speed you set is only used when you do things like "copy file.xxx com1" in a command line. ###### Path: chonsp.franklin.ch!usenet From: Neil Franklin Newsgroups: alt.folklore.computers Subject: Re: Comm port speed folklore Date: 24 Jul 1999 15:52:36 +0200 Organization: My own Private Self Lines: 32 Sender: neil@chonsp.franklin.ch Message-ID: <6uwvvqw3x7.fsf@chonsp.franklin.ch> References: <37993D35.1BD9@spamcop.net> <379fa511.1527216@news.pandora.be> X-Newsreader: Gnus v5.3/Emacs 19.34 lucvdv@null.net (Luc Van der Veken) writes: > > jp posted: > > I had noticed that the comm ports of my new computer at work > > were set at 9600. I reset them to the maximum speed. When > > I mentioned this to the tech, he said it didn't matter. The > > modem sets the speed and doesn't use the port speed. > > It's true. The port speed you set is only used when you do > things like "copy file.xxx com1" in a command line. It is semi-true. There actually exist 2 speeds. The computer-modem connection and the modem-modem connection. The first is set be the User, the second is negotiated by the modems. The lower of the 2 speeds is what you get when transfering data. With 9600 as the c-m you will be limiting your rate seriously. I allways set the c-m to about 2 times the max raw (uncompressed) m-m the device I have will stand. As example: This post will go over 38400 c-m and 14400+compress m-m. -- Neil Franklin, Nerd, Geek, Unix Wizzard and Guru, Hacker, Mystic neil@franklin.ch.remove http://neil.franklin.ch/ Computer: toy that speeds work, so you have more time to play with it ###### From: Digital.Magic@cadvision.com (John W Hall) Newsgroups: alt.folklore.computers Subject: Re: Comm port speed folklore Date: Sat, 24 Jul 1999 22:23:52 GMT Message-ID: <379a3a52.243107791@news.cadvision.com> References: <37993D35.1BD9@spamcop.net> X-Newsreader: Forte Free Agent 1.11/32.235 NNTP-Posting-Host: 207.148.142.219 X-NNTP-Posting-Host: 207.148.142.219 X-Trace: 24 Jul 1999 16:25:01 -0700, 207.148.142.219 Organization: CADVision Development Corporation (http://www.cadvision.com/) Lines: 22 X-NNTP-Posting-Host: 204.50.1.43 Path: chonsp.franklin.ch!pfaff.ethz.ch!news-zh.switch.ch!news-ge.switch.ch!news-fra1.dfn.de!news0.de.colt.net!colt.net!newsfeed.icl.net!news-spur1.maxwell.syr.edu!news.maxwell.syr.edu!news.idt.net!nntp.cadvision.com!news.cadvision.com!207.148.142.219 On Fri, 23 Jul 1999 21:12:37 -0700, jp wrote: >I had noticed that the comm ports of my new computer at work >were set at 9600. I reset them to the maximum speed. When >I mentioned this to the tech, he said it didn't matter. The >modem sets the speed and doesn't use the port speed. > >Is this true or folklore? The port speed, (max 115000, which is divided by 1, 2,3,4, or 5 etc), determines the rate of data transfer between the modem and the PC. It needs to be as fast enough to handle the data coming from or to the modem on the PC side, otherwise the modem has to wait. That depends on the bit rate and encoding used. If a compression protocol is used, and the modem is decompressing it (rather than passing it compressed to the computer and decompressing it there), the data rate coming out of the modem could be e.g. 4x the 'advertised' data rate, i.e. a typical 48KB/s connection may run at 48KB/s on the line side, but because of compression could be running at over 100KB/s on the computer side. If you port speed can't handle that, line data pauses momentarily. ###### From: lucvdv@null.net (Luc Van der Veken) Newsgroups: alt.folklore.computers Subject: Re: Comm port speed folklore Organization: . Message-ID: <379adfac.1046745@news.pandora.be> References: <37993D35.1BD9@spamcop.net> <379fa511.1527216@news.pandora.be> <6uwvvqw3x7.fsf@chonsp.franklin.ch> X-Newsreader: Forte Agent 1.5/32.451 MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit Lines: 34 Date: Sun, 25 Jul 1999 10:26:18 GMT NNTP-Posting-Host: 212.123.10.187 X-Complaints-To: systemgroup@telenet-ops.be X-Trace: afrodite.telenet-ops.be 932898378 212.123.10.187 (Sun, 25 Jul 1999 12:26:18 MET DST) NNTP-Posting-Date: Sun, 25 Jul 1999 12:26:18 MET DST Path: chonsp.franklin.ch!pfaff.ethz.ch!news-zh.switch.ch!iol.ie!colt.net!news.belnet.be!afrodite.telenet-ops.be!not-for-mail Neil Franklin posted: > lucvdv@null.net (Luc Van der Veken) writes: > > > > jp posted: > > > I had noticed that the comm ports of my new computer at work > > > were set at 9600. I reset them to the maximum speed. When > > > I mentioned this to the tech, he said it didn't matter. The > > > modem sets the speed and doesn't use the port speed. > > > > It's true. The port speed you set is only used when you do > > things like "copy file.xxx com1" in a command line. > > It is semi-true. > > There actually exist 2 speeds. The computer-modem connection and the > modem-modem connection. That's correct, but I don't think that's what the original question was about. In DOS or Win, you can set a default speed, but most communications software allows you to override this. I use "most" here just to be safe - actually I don't know anything that doesn't. The tech's reply was incorrect for another reason: it isn't the modem that sets the speed, it's the modem software you use. For example when creating "dial-up connections" under win9x or NT, it's _there_ that you set the serial line speed, not in the COM port defaults. The default is always 9600, yet I've used external V90 modems to connect to the internet without changing this, and got the full transfer speed (4-5 kBps in downloads at 42000 bps - phone line quality is rather poor here). ###### Newsgroups: alt.folklore.computers Subject: Re: Comm port speed folklore From: bmarcum@iglou.com X-Everything: Net-Tamer V 1.08X NNTP-Posting-Host: lou-ts7-54.iglou.com X-Original-NNTP-Posting-Host: lou-ts7-54.iglou.com Message-ID: <379b6f16@news.iglou.com> Date: 25 Jul 1999 16:09:58 -0500 X-Trace: 25 Jul 1999 16:09:58 -0500, lou-ts7-54.iglou.com Lines: 18 X-Authenticated-User: bmarcum X-Original-NNTP-Posting-Host: news-incoming.iglou.com Organization: IgLou Internet Services, Inc. Path: chonsp.franklin.ch!pfaff.ethz.ch!news-zh.switch.ch!iol.ie!colt.net!newsfeed.icl.net!newsfeed.tli.de!newsfeed1.news.nl.uu.net!sun4nl!uunet!ams.uu.net!ffx.uu.net!news.iglou.com!lou-ts7-54.iglou.com On 1999-07-23 johnny@spamcop.net said: >computers:204469 I had noticed that the comm ports of my new >computer at work were set at 9600. I reset them to the maximum >speed. When I mentioned this to the tech, he said it didn't matter. >The modem sets the speed and doesn't use the port speed. >Is this true or folklore? Questions about new computers are usually off topic for this newsgroup, and besides you don't give enough information for a definite answer. For example, what operating system and what applications do you use with the modem? What are the maximum speeds for your modem and the modem(s) at the other end? Can you find out the actual connect speed? Did you change the system default port speed, or the speed used in the application (this question might not be relevant for some systems)? It is true that modems generally set themselves to a speed no faster than the port speed, but your technician might be aware of other factors that limit the maximum speed to 9600 or less. ###### Newsgroups: alt.folklore.computers From: bill@wjv.com.REMOVEME (Bill Vermillion) Subject: Re: Comm port speed folklore Organization: W.J.Vermillion - Orlando / Winter Park FL Message-ID: References: <37993D35.1BD9@spamcop.net> Date: Mon, 26 Jul 1999 03:27:29 GMT Lines: 20 Path: chonsp.franklin.ch!pfaff.ethz.ch!news-zh.switch.ch!iol.ie!diablo.theplanet.net!news-spur1.maxwell.syr.edu!news.maxwell.syr.edu!news.iag.net!tous2.oau.org!alfred!bilver.wjv.com!bill In article <37993D35.1BD9@spamcop.net>, jp wrote: >I had noticed that the comm ports of my new computer at work were >set at 9600. I reset them to the maximum speed. When I mentioned >this to the tech, he said it didn't matter. The modem sets the >speed and doesn't use the port speed. >Is this true or folklore? Older modems talked to the DCE/DTE interface at their data rate. Now the modems negotiate a data connection speed between them, but the rate at which the modem talks to the computer is based on it's speed, or if it's in a rotating gettydef definition it will keep tyring the next speed to try to connect to the modem each time a CR is struck if it can't figure out what you typed. -- Bill Vermillion bv @ wjv.com ###### From: wwheco1@aol.comheathkit (Bill Wilkinson) Newsgroups: alt.folklore.computers Subject: Re: Comm port speed folklore Lines: 22 NNTP-Posting-Host: ladder06.news.aol.com X-Admin: news@aol.com Date: 31 Jul 1999 20:16:12 GMT References: <37993D35.1BD9@spamcop.net> Organization: AOL http://www.aol.com Message-ID: <19990731161612.14803.00000314@ng-cj1.aol.com> Path: chonsp.franklin.ch!pfaff.ethz.ch!news-zh.switch.ch!news-ge.switch.ch!news.maxwell.syr.edu!howland.erols.net!portc02.blue.aol.com!audrey03.news.aol.com!not-for-mail jp johnny@spamcop.net wrote: >I had noticed that the comm ports of my new computer at work >were set at 9600. I reset them to the maximum speed. When >I mentioned this to the tech, he said it didn't matter. The >modem sets the speed and doesn't use the port speed. > >Is this true or folklore? > More information is needed: 1) Mainframe, midrange, desktop? 2) Operating system. 3) Modem and communications software. 4) Was the tech an Entex employee? --Bill -- Bill Wilkinson email: wxwilki@aol.com Heathkit Page: http://members.aol.com/wwheco1/index.htm ###### From: jsavard@ecn.ab.ca () Newsgroups: alt.folklore.computers Subject: Re: Comm port speed folklore Date: 2 Aug 99 03:42:06 GMT Organization: Edmonton Community Network Lines: 31 Message-ID: <37a5138e.0@ecn.ab.ca> References: <37993D35.1BD9@spamcop.net> <19990731161612.14803.00000314@ng-cj1.aol.com> NNTP-Posting-Host: freenet.edmonton.ab.ca X-Trace: news.sas.ab.ca 933563156 8815 198.161.206.2 (2 Aug 1999 03:05:56 GMT) X-Complaints-To: news@sas.ab.ca NNTP-Posting-Date: 2 Aug 1999 03:05:56 GMT X-Newsreader: TIN [version 1.2 PL2.6] Path: chonsp.franklin.ch!pfaff.ethz.ch!news-zh.switch.ch!news-ge.switch.ch!isdnet!logbridge.uoregon.edu!newsfeed.direct.ca!cyclone.bc.net!rover.ucs.ualberta.ca!sas.ab.ca!ecn.ab.ca!jsavard jp johnny@spamcop.net wrote: >I had noticed that the comm ports of my new computer at work >were set at 9600. I reset them to the maximum speed. When >I mentioned this to the tech, he said it didn't matter. The >modem sets the speed and doesn't use the port speed. >Is this true or folklore? Well, for many typical PC computers, if the modem is running at speeds above 1200 baud, the modem can use techniques like data compression to move data more quickly. Also, the start and stop bits are omitted from characters. Hence, your communications port could run at 19,200 baud to talk to a modem running at 14,400 baud. Handshaking would allow your modem to tell the computer to pause before sending more characters; this extra speed allows the fancy features of the modem to be useful. Of course, if you have a PC, I don't know how its communications ports could be "set" at 9600 baud, since their speed can be altered by any program that uses them, such as whatever program is being used to make use of your modem. But some older computers do have a physical switch on the back that controls the speed of their RS232 ports, perhaps; certainly many terminals had such switches. Definitely, though, the modem itself can't alter the speed of the UART hooked to the RS232 port it is connected to - not directly. A computer might try changing its port speed to make the connection work. John Savard ###### From: Mike Swaim Subject: Re: Comm port speed folklore Newsgroups: alt.folklore.computers References: <37993D35.1BD9@spamcop.net> <19990731161612.14803.00000314@ng-cj1.aol.com> <37a5138e.0@ecn.ab.ca> Organization: PointeCom User-Agent: tin/pre-1.4-980818 ("Laura") (UNIX) (FreeBSD/2.2.8-RELEASE (i386)) Lines: 15 Message-ID: <9uip3.63494$AU3.1717573@news2.giganews.com> NNTP-Posting-Date: Mon, 02 Aug 1999 10:06:45 CDT X-Trace: sv1-f74U/aRyLY8cB0E2GpdDuzrzboBb9YffOxwBfVSBXj5xJOPhTRyhQpBkw7nsAaUxwk9Yms2Nb9T/sIN!sAmhe3DxN+0= X-Complaints-To: abuse@GigaNews.Com X-Abuse-Info: Please be sure to forward a copy of ALL headers X-Abuse-Info: Otherwise we will be unable to process your complaint properly Date: Mon, 02 Aug 1999 15:06:45 GMT Path: chonsp.franklin.ch!pfaff.ethz.ch!news-zh.switch.ch!newsfeed-zh.ip-plus.net!news.ip-plus.net!News.Amsterdam.UnisourceCS!skynet.be!news-spur1.maxwell.syr.edu!news.maxwell.syr.edu!newsfeed.cwix.com!207.207.0.27!nntp2.giganews.com!news2.giganews.com.POSTED!gemini.c-com.net!swaim jsavard@ecn.ab.ca wrote: : Of course, if you have a PC, I don't know how its communications ports : could be "set" at 9600 baud, since their speed can be altered by any : program that uses them, such as whatever program is being used to make use : of your modem. I believe that it's the default setting. My software to communicate with my handheld PC always uses the default setting. This is annoying because the handheld's default setting is 19,200 bps. (For those wondering, all the software involved was written by MicroSoft.) -- Mike Swaim, Avatar of Chaos: Disclaimer:I sometimes lie. Home: swaim@c-com.net Alum: swaim@alumni.rice.edu Quote: "Boingie"^4 Y,W&D ###### From: kthomas@gwdg.de (Philipp Thomas) Newsgroups: alt.folklore.computers Subject: Re: Comm port speed folklore Date: Tue, 03 Aug 1999 21:23:20 GMT Organization: GWDG, Goettingen Lines: 14 Message-ID: <37a75908.1167564@news.gwdg.de> References: <37993D35.1BD9@spamcop.net> <19990731161612.14803.00000314@ng-cj1.aol.com> <37a5138e.0@ecn.ab.ca> <9uip3.63494$AU3.1717573@news2.giganews.com> NNTP-Posting-Host: ras23-183.gwdg.de Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit X-Trace: gwdu67.gwdg.de 933715401 28060 134.76.23.183 (3 Aug 1999 21:23:21 GMT) X-Complaints-To: news@gwdg.de NNTP-Posting-Date: 3 Aug 1999 21:23:21 GMT X-Newsreader: Forte Agent 1.5/32.451 X-No-Archive: yes Path: chonsp.franklin.ch!pfaff.ethz.ch!news-zh.switch.ch!news-ge.switch.ch!news-fra1.dfn.de!news-lei1.dfn.de!news-nue1.dfn.de!news-han1.dfn.de!news.gwdg.de!not-for-mail On Mon, 02 Aug 1999 15:06:45 GMT, Mike Swaim wrote: > I believe that it's the default setting. Yep, and with a reason. AFAIK, IBM decided to only implement polling mode in the BIOS for the serial port of the PC and 9600 was the fastest you could do in polling mode. Everything higher required interrupt driven communication which you do implement yourself. Philipp -- Close the windows! The penguin is freezing.