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Path: euryale.cc.adfa.oz.au!newshost.anu.edu.au!harbinger.cc.monash.edu.au!munnari.OZ.AU!news.ecn.uoknor.edu!news.cis.okstate.edu!newsfeed.ksu.ksu.edu!news.mid.net!newsfeeder.gi.net!newsfeed.internetmci.com!in2.uu.net!netnews.nwnet.net!symiserver2.symantec.com!usenet From: tedm@agora.rdrop.com Newsgroups: comp.unix.bsd.freebsd.misc Subject: Re: ping works, telnet won't Date: 11 Jul 1996 05:22:41 GMT Organization: Symantec Corporation Lines: 38 Message-ID: <4s2331$nmq@symiserver2.symantec.com> References: <4r2kho$f5p@agate.berkeley.edu> <4r3gkm$s7j@uriah.heep.sax.de> <4rrsl7$1eu@uriah.heep.sax.de> Reply-To: tedm%toybox@agora.rdrop.com NNTP-Posting-Host: 198.6.34.1 X-Newsreader: IBM NewsReader/2 v1.2 In <4rrsl7$1eu@uriah.heep.sax.de>, j@uriah.heep.sax.de (J Wunsch) writes: >tedm@agora.rdrop.com wrote: > >> My theory is that the sio.c driver in FreeBSD is probably written for just a >> few 16550A chipsets, such as SMC's, the original (Nationals) etc and hasn't >> been tested and debugged thoroughly on the cheaper and crummier chipsets, >> as a result the driver/chipset combination is dropping characters somewhere. > >That's a bit unfair to the author of sio, in particular since you >apparently neither know him nor attempted to approach him on this. ;-) > NO! I certainly didn't mean to sound as though this is his fault! I wouldn't expect anyone writing a device driver to have _every_ version of every garbage-grade rip off copy of the hardware at their disposal to test with! Besides that, the serial port UART chip depends on some other support chips as well, at least the ones I've seen seem to, and these can vary as well. Also, a lot of these combo- UART chips are embedded on a motherboard and would not be possible to obtain and test with even if someone wanted to. The PC serial port has probably been the worst of all PC peripherals anyhow, for example I have sitting under my desk a 386/20 with a genuine 16550 on a combo-IDE card in it. Under earlier versions of OS/2 I couldn't get that to work, but I could stick the card into a 386/33 and it would work great under the same versions. I also remember many, many iterations of the OS/2 serial port driver from IBM. In fact, I have some "known good" versions that I keep on floppy just in case IBM breaks it again. Of course I know that FreeBSD is a completely different operating system, but hey, if IBM's programmers took a dozen iterations to come up with some working serial port drivers and they had the resources of the company to draw on to purchase as many of the crummy, garbage serial-port cards as they wanted, I think it is amazing that the driver works at all! I come from the school of buying the hardware for the software, and I just wanted to convey that. Ted