dbj@rice.EDU (Dave Johnson) (07/24/86)
I just bought a US Robotics Courier 2400 baud modem, and I'm having some
problems with it that surprise me in light of some of the glowing reviews
of it I've read on the net. I haven't been able to try it at 2400 baud
yet (nobody to talk to yet), but I get MUCH worse performance at 1200
baud than I'm used to. I've tried many modems on this phone line (I used
to test different kinds of modems for where I worked), and none have given
me this much trouble with line noise. In particular, I've used a Rixon
R212A 1200 baud modem and a Hayes SmartModem 1200 a lot lately, and both
gave virtually flawless 1200 baud performance.
So, my question is does anybody else have this kind of trouble with the
Courier 2400, or is it just mine? I remember something about the early
ones of them having line noise problems if you got a version of the PROM
earlier than some revision level, but I don't remember what that level
was. As an alternative to this, can anybody suggest a 2400 baud modem
that works well at both 1200 baud and 2400 baud?
Thanks...
Dave Johnson
Dept. of Computer Science
Rice University
UUCP: {drillsys,lbl-csam,cbosgd,shell,convex,sun,texsun}!rice!dbj
ARPA: dbj@rice.EDU, dbj@rice.ARPAsteve@wolf.UUCP (Steve Harrison) (07/26/86)
> I just bought a US Robotics Courier 2400 baud modem, and I'm having some > problems with it that surprise me in light of some of the glowing reviews > of it I've read on the net. I haven't been able to try it at 2400 baud > yet (nobody to talk to yet), but I get MUCH worse performance at 1200 > baud than I'm used to. I've tried many modems on this phone line (I used > to test different kinds of modems for where I worked), and none have given > me this much trouble with line noise. In particular, I've used a Rixon > R212A 1200 baud modem and a Hayes SmartModem 1200 a lot lately, and both > gave virtually flawless 1200 baud performance. > > So, my question is does anybody else have this kind of trouble with the > Courier 2400, or is it just mine? I remember something about the early > ones of them having line noise problems if you got a version of the PROM > earlier than some revision level, but I don't remember what that level > was. As an alternative to this, can anybody suggest a 2400 baud modem > that works well at both 1200 baud and 2400 baud? > > Thanks... > > Dave Johnson > Dept. of Computer Science > Rice University > > UUCP: {drillsys,lbl-csam,cbosgd,shell,convex,sun,texsun}!rice!dbj > ARPA: dbj@rice.EDU, dbj@rice.ARPA Dave, I seem to be one of the few that didn't care for the USR 2400's. As a matter of fact we sold 8 of them to UCSD and other individuals. They thought they got a great deal. Since selling them almost 100% percent of them have been junked and replaced with something more reliable. Steve Harrison Systems'n'Software ihnp4!jack!wolf!steve
bobw@ncoast.UUCP (Bob Weinberg) (07/28/86)
I have had several Courier 2400 modems at my home, and still have the last one in addition to the trusty old Hayes 1200. I desperately want to use 2400 baud when I can, especially for uucp to our work system. Unfortunately, there are MANY times, when the Courier simply will NOT connect to a distant carrier at 1200 baud, when the Hayes always does. Actually, the Courier has never connected to the systems that I have this problem with. That is why I'm forced to use 2 modems. The Hayes for everything, and the Courier *IF* they have 2400 on the otherside, *AND* the signal is strong enough. I also note, a greater noise level (you know }}}}v}v}}}}}) with the Courier. I live in an area about 25 miles from Cleveland Ohio, and I have not found a way to solve the problem. A number of Cleveland sites do have 2400 baud, and it works perfectly as advertised, but I can't connect even at 1200 to others. I spoke to a US Robotics Tech on my first unit and they claimed to have GREATER sensitivity specs than Hayes at 1200 baud. He couldn't understand why I had the problem. Said he'd call me back, but never did. I have sold the various units to other people who have had no problems. It seems to have something to do with the specific phone situation out here, and the Courier itself by design. Any comments or suggestions out there. -- Robert L. Weinberg ...decvax!cwruecmp!ncoast!bobw Tridelta Indusries, Inc. ...decvax!cwruecmp!ncoast!tdi2!bobw V.P. Technology
kjpires@ucbcad.BERKELEY.EDU (Kurt J. Pires) (07/31/86)
We have a bank of Courier 2400 baud modems (rack-mounted) and 30 university owned modems in people's homes... When we installed them (and gave out the modems to the users), most said that at 2400 baud there was LESS noise... Personally, I find much less noise, but the signal around here, I assume, is pretty strong. (How do you know if the signal is strong?) The biggest problem is that many of our modems are DOA. Of the 30 home modems, we had 4 bad power supplies and 2 bad modems. Also, one pair of the rack-mounted modems was bad. Kurt Pires
jc@sdcsvax.UUCP (John Cornelius) (08/08/86)
I've seen several articles kvetching on 2400 baud modem performance in the past several weeks. I think the definitive article on the subject was submitted by Brian Kantor about 2 months ago to net.dcom. The fundamental problem is that many of the modems are not V.22 BIS compatible. Brian pointed out at that time that the US Robotics was not V.22 BIS. Historically US Robotics has not been very heavy on the engineering side of the business. On the other hand they do build inexpensive modems. Actually, my biggest beef with USR is the way they do business, although I'm not fond of their product either. For the past year or so I have been under the impression that V.22 BIS modems which were advertised for sale were mostly junk, including the Hayes and one that the company I used to work for sold. That has recently begun to change. The units that UCSD has selected were made by Intertec and they seem to have success with them. In addition the Racal Vadic modems meet the spec, not that one would expect anything else from Racal Vadic. The new model Anchor Lightning modems are also in spec and work rather well. I believe that all of these modems can be had with MNP error correction. John Cornelius jc@sdcsvax