thad@cup.portal.com (Thad P Floryan) (01/11/91)
All this talk about Telebits "doing" bit shaving is interesting, but reading the description of the visible effects of the problem reminds me of something else that caused the IDENTICAL problems 10 years ago at 1200baud and for which a sound technical explanation (AND FIX) existed: speed tolerance mismatch when calling Racal-Vadic Triple-Modems, model 3467, which operated in 103 mode (0-300 bps), 212A mode (1200 bps) and VA3400 mode (also a nominal 1200 bps). My 212A modems (then) had NO problems calling anywhere except to one site, and that particular site had ONLY the Vadic modems. Vadic modems had the misfeature of an on-board jumper which would select the "nominal 1200 bps" to be EITHER the ranges: 1186 to 1204 bps, or 1196 to 1219 bps 212A modems' bit rates are specified as 1182 to 1212 bps. From the factory, Vadic modems were set to the "1196 to 1219 bps" range and, of course, worked fine with other Vadic modems. But if one called using a 212A modem into a Vadic (or vice versa), the bit rate variation would cause complete garbling after about 20 characters or so, and rendered the connection useless due to the cumulative effects of the 0.6% bit rate difference. So, my conjecture is that the problem may not be "bit shaving" but, in fact, something like a bit rate mismatch. Hmmm, wonder where the Vadic engineers went after Vadic went belly up? :-) [ NOTE that Vadic was in Santa Clara and Telebit was in Cupertino (2 miles away) and is now in Mountain View, about 4 miles from the old Vadic site ] In any event, I had to "fight" that site admin for quite a while; he kept insisting his modems worked fine for him (sure, all his were Vadics) and that any "problem" had to be in my modem. Finally convinced him to RTFM, and he THEN adjusted that jumper on his Vadics, and all worked fine since. Now that same site has Codex modems which are ALSO improperly configured (by the SAME guy, sigh) regarding its multi-mode handshake decoding sequence "song-and-dance" as to what to set its modulation technique to be. Sigh. Causes real problems using V.32/V.42 and, I hear, Telebit (ah, the irony :-). My modems again can call ANY site in the WORLD with no problems; only that one site has the problem, and I'm still dorking-around getting that guy to "fix" HIS problem; to be fair, he's been going out of his way to assist me regarding remote tests, etc., but I believe I could solve that problem if he'd just loan me the manual for a day and I read it to see how to configure Codex modems, and then DO it. For what it's worth, the "site" to which I'm referring is the same one that was mentioned in John Ruckstuhl's (ruck@sphere.UUCP) anecdote re: ... said, essentially, "I *won't* carry it because I don't see that it is beneficial to HP". I wrote back asking him to reconsider, hoping that he wouldn't apply a criterion to unix-pc that he wouldn't apply to, say, rec.arts.tv.soaps. This logic, and a "spirit of USENET" appeal failed to persuade him. And yet, that site, HP-Labs (Palo Alto) does carry alt.sex.pictures and, of course, alt.sex.bondage. Obviously pornography and kinky sex IS important to HP-Labs, right? :-) The above is NOT meant to cast aspersions on Hewlett-Packard. It's just that every company has its share of obstinate people. Thad Floryan [ thad@cup.portal.com ]
gst@gnosys.svle.ma.us (Gary S. Trujillo) (02/07/91)
In article <1479@das13.snide.com>, dave@das13.snide.com (Dave Snyder) writes: > In article <972@gnosys.svle.ma.us>, gst@gnosys.svle.ma.us > (Gary S. Trujillo) writes: > > > Anyway, though it took a lot of work and fiddling, I did find a way to > > configure my T2500 for dialin that permits it to do *true* autobauding > > [no BREAKS, CRs, or other characters need to be sent upon initial login] > > Sounds good... could you please post or mail the "S" register settings for > this configuration... Right you are, sir. Enjoy! E1 F1 M1 Q6 T V1 W0 X3 Y0 &P0 &T4 Version GA2.00 S00:000 S01=000 S02=043 S03=013 S04=010 S05=008 S06=002 S07=040 S08=002 S09=006 S10=007 S11:050 S12=050 S18=000 S25=005 S26=000 S38=000 S41=000 S45=000 S47=004 S48=000 S49=000 S50=000 S51=255 S52:002 S54:003 S55=000 S56=017 S57=019 S58:002 S59=000 S60=000 S61=150 S62=003 S63=001 S64=000 S65=000 S66=000 S67:001 S68=255 S69=000 S90=000 S91=000 S92:001 S93:004 S94=001 S95=000 S96=001 S100=000 S101=000 S102=000 S104:003 S105=001 S110:000 S111:030 S112=001 S121=000 S130=002 S131:001 S150=000 S151=004 S152=001 S153=001 S154=000 S155=000 S160=010 S161=020 S162=002 S163=003 S164=007 S255=000 -- Gary S. Trujillo gst@gnosys.svle.ma.us Somerville, Massachusetts {wjh12,bu.edu,spdcc,ima,cdp}!gnosys!gst
gandrews@netcom.COM (Greg Andrews) (02/08/91)
In article <980@gnosys.svle.ma.us> gst@gnosys.svle.ma.us (Gary S. Trujillo) writes: > [Gary's modem config that doesn't require sending breaks] > >E1 F1 M1 Q6 T V1 W0 X3 Y0 &P0 &T4 Version GA2.00 >S00:000 S01=000 S02=043 S03=013 S04=010 S05=008 S06=002 S07=040 S08=002 S09=006 >S10=007 S11:050 S12=050 S18=000 S25=005 S26=000 S38=000 >S41=000 S45=000 S47=004 S48=000 S49=000 >S50=000 S51=255 S52:002 S54:003 S55=000 S56=017 S57=019 S58:002 S59=000 >S60=000 S61=150 S62=003 S63=001 S64=000 S65=000 S66=000 S67:001 S68=255 S69=000 >S90=000 S91=000 S92:001 S93:004 S94=001 S95=000 S96=001 >S100=000 S101=000 S102=000 S104:003 S105=001 >S110:000 S111:030 S112=001 >S121=000 S130=002 S131:001 >S150=000 S151=004 S152=001 S153=001 S154=000 S155=000 >S160=010 S161=020 S162=002 S163=003 S164=007 S255=000 > Pretty normal Unix settings... What did you change to eliminate the need for breaks? -- Greg Andrews gandrews@netcom.COM
gst@gnosys.svle.ma.us (Gary S. Trujillo) (02/21/91)
In <8653@gollum.twg.com> david@twg.com (David S. Herron) writes: >In article <984@gnosys.svle.ma.us> gst@gnosys.svle.ma.us (Gary S. Trujillo [me] ) writes: > > [ stuff about autobauding ] > Yes.. that's a fairly simple thing to do .. > but *WHY* do this? I run mine (3b1 with TB+) with the interface > speed locked at 19200 and have no problem... Since you ask, I cite two reasons: 1. With the interface speed locked, UNIXpc OBMs have trouble talking to Telebit modems. 2. It takes forever for an interrupt signal to be acted on with interface speed locked, since there's a whole bunch of char- acters buffered up in the modem. -- Gary S. Trujillo gst@gnosys.svle.ma.us Somerville, Massachusetts {wjh12,bu.edu,spdcc,ima,cdp}!gnosys!gst