Relay-Version: version B 2.10 5/3/83; site utzoo.UUCP Path: utzoo!mnetor!uunet!husc6!cmcl2!nrl-cmf!ukma!david From: david@ms.uky.edu (David Herron -- Resident E-mail Hack) Newsgroups: comp.dcom.modems Subject: Re: Looking for a fast modem < $1000. Message-ID: <7753@g.ms.uky.edu> Date: Sun, 22-Nov-87 23:33:54 EST Article-I.D.: g.7753 Posted: Sun Nov 22 23:33:54 1987 Date-Received: Wed, 25-Nov-87 06:27:50 EST References: <48400001@uxe.cso.uiuc.edu> Reply-To: david@ms.uky.edu (David Herron -- Resident E-mail Hack) Organization: U of Kentucky, Mathematical Sciences Lines: 83 In article <48400001@uxe.cso.uiuc.edu> richman@uxe.cso.uiuc.edu writes: > What is the fastest bps modem commercially available under $1000. which > works over standard phone lines in a full-duplex mode? > >What I'm looking for is something ~9600 - 19,200 which will interface >a terminal with a campus mainframe via Ma Bell. Any suggestions? Well ... seeing that I'm doing just that right now I suppose I'll tell you what I've got. I'm testing Telebit TrailBlazer's to see if we want to get one/many. We almost certainly want to get one, but who knows about many. Anyway ... for the description. This modem uses a funky highly proprietary protocol. It cuts the telephone bandwidth into some large number of channels that can each do 0, 2, 4, or 6 bits of data. There's a 68010 in the modem that (among other things) examines the phone line occasionally to see how each of the channels are doing. If one is getting bad it'll drop the number of bits it's handling and if it's really bad it'll drop it completely. The baud rate will vary from something low to approx 18,000 baud in something like 300 baud increments. It also works as a normal 300/1200/2400 (+MNP) modem. It does all this over extremely normal phone lines. (I live in the student ghetto around campus ... the phone system leaves something to be desired ... the modem says it's doing around 15,000 baud right now). It's fun watching rn paint a screen faster than it does on the terminal in my office! :-) And "rain" is fun too ...! The cost? Well, it's a tad more than you wanted. The list price is $1300. Per modem. But Telebit has a deal going where they'll sell (up to two) modems to people who are in the Usenet maps for half price. ~$670 Some other features of the modem is that it can be told that to watch for packets from XMODEM/KERMIT/UUCP "g" protocols ... when it see's the packet, it accepts it and acks it ... then it passes the data on to the other modem using it's normal protocol ... at the other end the other guy creates the proper packet again and swallow the ack which'll come back. In other words .. you "sidestep" the problems you get with other fast modems where the protocol being used will cause problems with line turnaround to get acks back to the sender. I have only one reservation. It's a proprietary protocol which will only work with Trailblazers. There are some almost-standards for 9600 baud (at least I think there are some standards), and telebit may get shut out of the game. However, there are whole bunch of proprietary modems in this speed range, so maybe the standards haven't settled down yet. I think also that Telebit might be able to insert rom's and have the hardware emulate just about any of the protocols w/o too much problem. It seems likely that's the way they were able to also have the modem handle 300/1200/2400 baud ... there isn't a second set of modem chips in the box for instance. This special deal from Telebit has put a lot of Telebit's in the hands of a lot of people around the country. This will help to establish a good niche for telebit ... if only as a heavily loved part of the Usenet backbone :-). There have been reports of 9000 baud to 14000 baud throughput using these modems with UUCP transfers. This is real throughput as reported by uucp, and includes the protocol overhead. This is using long distance phone lines. etc etc. I LOVE THIS MODEM! (Note that I am in no way connected with either telebit or the vendor we will be buying through. I am merely a customer and an interested observer...) -- <---- David Herron -- Resident E-Mail Hack <---- or: {rutgers,uunet,cbosgd}!ukma!david, david@UKMA.BITNET <---- "The market doesn't drop hundreds of points on a normal day..." -- <---- Fidelity Investments Corporation