aad@stpstn.UUCP (Anthony A. Datri) (09/27/88)
I've got a pulp catalog here called "Computer Bargain Line", and it has an ad in it for a $160 "modem" that sends up to 9600 baud over 120V power lines. The company is CRC Electronics. Anyone have any comments? I'd never buy one because I wouldn't trust plugging anything else into the same circuit, but I'm curious. Also, I've almost decided to bite the bullet and shell out the $400 and buy my 2400 baud modem from Hayes, since people have reported brain-damage (unspecified) in my previous favorite, the Packard-Bell. Any comments there? -- @disclaimer(Any concepts or opinions above are entirely mine, not those of my employer, my GIGI, or my 11/34) beak is beak is not Anthony A. Datri,SysAdmin,StepstoneCorporation,stpstn!aad
jbn@glacier.STANFORD.EDU (John B. Nagle) (09/28/88)
Power line modems are not at all uncommon. They generally use an
FM carrier in the 100KHz range and are typically just frequency-shift
keying devices. Range usually includes everybody on the same power
transformer. Interference from various sources, including power-line
intercoms, power-line based control systems such as the BSR units, control
signals sent by power companies, antique jukebox remotes, master clock systems,
music distribution systems, and other various arcane devices, is possible.
There's no frequency coordination for signals via the power line. So
products of this type tend to not work right in some installations, which makes
the technology unpopular.
Incidentally, it's quite proper to speak of a power line modem as a
"modem". Most modems are telephone-line oriented, but there are also RF
modems for radio links, for example.
John Nagledave@onfcanim.UUCP (Dave Martindale) (09/29/88)
In article <2148@stpstn.UUCP> aad@stpstn.UUCP (Anthony A. Datri) writes: > >Also, I've almost decided to bite the bullet and shell out the $400 >and buy my 2400 baud modem from Hayes, since people have reported >brain-damage (unspecified) in my previous favorite, the Packard-Bell. >Any comments there? The Hayes 2400 is also somewhat brain-damaged. It's been a while since I looked at one, but I do remember that 1) There is no direct way to tell the modem to send back result codes when in originate mode, but not in answer mode. (You can get around this by having it reset to the state stored in EEPROM on DTR drop, but see #2) 2) You can tell the modem to hang up when DTR drops, OR to reset itself to saved settings when DTR drops, but not both 3) The DTR light on the front panel is always on, regardless of the actual state of DTR, even when the modem is configured to use DTR to prevent answer/hang up the phone On the other hand, it is better than the Hayes 1200. We have a Vadic VA2400MNP that works well - it's not too configurable, but it generally does what you want. However, its MNP implementation doesn't seem able to talk to anything else.
steve@ivucsb.UUCP (Steve Lemke <steve>) (10/01/88)
In article <16285@onfcanim.UUCP> dave@onfcanim.UUCP (Dave Martindale) writes: <In article <2148@stpstn.UUCP> aad@stpstn.UUCP (Anthony A. Datri) writes: <> <>Also, I've almost decided to bite the bullet and shell out the $400 <>and buy my 2400 baud modem from Hayes, since people have reported <>brain-damage (unspecified) in my previous favorite, the Packard-Bell. <>Any comments there? < <The Hayes 2400 is also somewhat brain-damaged. It's been a while Back when I used to run a BBS, I remember looking for a 2400 baud modem, and finding out that BBS program authors felt the same way about the Hayes - it didn't really work the _same_ as a Hayes 1200, therefore making the Hayes 2400 "not Hayes compatible". However, U.S. Robotics seemed to have done things right, and everyone went wild over the USR Courier 2400 (one of which I bought for my board). It's been working for about four years now, and I still think that it's one of the best 2400 baud modems there is. The manual is well- written, and should you lose it, all of the commands and DIP switch info is printed on the bottom of the modem (what an idea!). Also, if you can't quite get to the bottom of the modem, but need info on a command, you can type "AT$" and it will print out a list of commands (info is also avaiable on dialing: "ATD$" and S-registers "ATS$"). The usenet system I'm currently using (ivucsb) is using my Courier, but they just ordered one for their own use (so I can have mine back). I believe they got it for something around $350 or so, and there's also a "USR Sportster" model available (budget model of the Courier, but same basic design and signal processing chips) for a little over $200. ----- Steve Lemke -------------- (What do you mean I only get five lines?) ----- Internet: steve@ivucsb.UUCP; lemke@apple.COM AppleLink: LEMKE ----- uucp: pyramid!comdesign!ivucsb!steve CompuServe: 73627,570 ----- alt.uucp: {decwrl!}sun!apple!lemke GEnie: S.Lemke