DSDC-SDT2@GUNTER-ADAM.ARPA (Walt Livingston) (02/20/85)
Here in the deep south, also known as "red neck country" we don't have packet radio repeaters, on-the-air BBoards, etc. In fact, we are just getting into computerized RTTY.(No jokes please, it's a bad situation). I am trying to get some interest up here in Montgomery Alabama, in using our computers (almost every ham has one now) for hobby; research; public service; etc., and need some info from the rest of the ham community. How does a club get into packet switching, what cost, what equipment is needed, what programs available, etc. The whole gammet (sp). That part out of the way, how about some programs for such computers as the C64, VIC 20, IBM-PC, CoCo, Timex, etc. Is there a repository somewhere within info-hams that has such programs (logging, duping, beam headings, circuit board design, etc). If I could get hold of such programs and info I can get some interest generated. Altho' Montgomery is "a hick city (?)" we do have some of the finest computer talent around. We have the Data Systems Design Office (USAF) where I work, with 11 large mainframes, 16 Mini's, and over 3000 micro's available. We also have the Air Force Air War College where all the prof's get formal military training. We have a very active Red Cross (ham wise) as well as Civil Defense (state, and county), and I can see the need for computerized traffic. Many hams are NTS inclined, as well as local net liaisons, and mostly, we have our share of disasters. Any info, programs, hints, nasty remarks (not really) will be much appreciated. Mucho thnks in advance. 73's Walt WA4YCM (Central Alabama Dstrict Emergency Coordinator) -------
clements@bbncd1.arpa (Bob Clements) (02/20/85)
Walt, I can't help much with your question about logging, beam heading or board design programs. But I can chew your ear off about packet radio at any length you want. The basic setup of packet radio as it has evolved so far is that each ham has a terminal or a little computer with a terminal emulator program, and he has a TNC (Terminal Node Controller) and a radio, usually 2 meters but also HF and other VHF bands. The TNC is a single board computer with a modem, transmitter control, serial ports, protocol and so on all ready to go. The hookup is literally a terminal on one side (DB25 connector) and three signals to the radio on the other side, namely transmit audio, receive audio and push-to-talk. TNC's are available from TAPR, GLB, AEA, and some others, and according to the Gateway that just came out, they will be available from Heathkit. Most packet radio operation is simplex (145.01 MHz on most of the East Coast). To get farther than your own neighborhood, you relay through other stations, also on the same simplex channels. Your TNC allows others to relay through you. This is called "Digipeating". Typically, a club will put up a digipeater at a good site and everybody can digipeat through it or go directly to those in their neighborhood. The thing that comes as a surprise to most 2-meter operators is that a dozen or so QSO's can be going on at once, all on the same simplex frequency, without interference. This is because each station sends only an occasional short burst of data when the operator finishes typing a line. Most of the channel time is idle. If two stations happen to transmit at once, so that a transmission is lost in the QRM, the protocols in the TNC take care of re-sending the packet until it gets through. To keep interest up in the area, it is good to establish a Mailbox or Bulletin board system. Most of these (about 25 and climbing) are based on the Xerox 820 boards that were available a while ago. They use software developed by Hank, W0RLI. Many of these are linked together by HF on 20, 30 and 40 meters. I have posted the W0RLI software on SIMTEL20. (It's about time to send an update, now that I think of it. The new features of automatic mail forwarding among BBS's aren't in the current one on SIMTEL20.) Hank's software has been mentioned in Gateway and 73 magazine. I'll cut this message short here. Let me know if I can expand on any of this for you. I guess I'll CC: this to info-hams, too. Anybody on the list who wants to chat about Packet Radio and packet BBS's, please do! 73, Bob Clements (K1BC)
andy@aids-unix.ARPA (Andy Cromarty) (02/21/85)
Walt, The Red Cross in Palo Alto has committed pretty heavily to the packet radio system produced by the Tuscon Amateur Packet Radio (TAPR) group. TAPR has a board (a "Terminal Node Controller," or "TNC") that comes as a kit for something like $300. Heath has just announced their own kit version of the TAPR design for the same amount, I believe -- see this month's 73 magazine. The TAPR TNC's are professional-quality design, good-looking, and work like a champ. One end plugs into your radio (usually your HT), the other end plugs into your computer terminal (or your home computer running a terminal emulator program), and you're on the air. Done. Sit down and type; QSO in progress. Since you say your guys have home computers already, all they need is the TAPR or Heath "Terminal Node Controller" and the program that lets their PC act as a terminal to another computer. There are other vendors of packet systems, perhaps most notably AEA (who makes an assembled version of the TAPR board for five or six hundred dollars) and GLB (which makes a low-end system with much or most of the TAPR TNC's capability for fewer dollars.) We have put together a complete package for our own (Red Cross) use in a single aluminized attache case that includes a small Texas Instruments terminal with thermal printer, a TAPR board, and a 2-meter HT; you can carry it in one hand. (It does require 120 volt AC; we're working on a 12-volt version.) It's pretty straightforward to assemble this sort of package, if you decide you need it for Red Cross disaster services operations. We have also used it for Simulated Emergency Test, the county-wide Medical Exercise, and other drills, and we've learned a lot about how packet can be used for emergency applications (including the problems it doesn't solve). Overall, it's a very impressive thing for a fire marshall or police chief to be able to *see* printed radiograms being sent back and forth between emergency stations -- it usually beats anything they have at their disposal for disaster communications hands down. The next step is to put up repeaters in your area, once local hams can converse via packet. This is a least as easy as putting up a regular two-meter repeater. As a matter of fact, every TAPR board *is* a repeater (a "digipeater") without you doing anything special to it, at the same time that it's your personal TNC, so you can get along for a while without installing special high-level repeaters in your area if everyone is within 2-meter FM simplex distance of the next guy. Most of us who work for the Red Cross leave our stations on the air 24 hours a day as digipeaters; if I want a QSO when I get home from work at night, I just sit down at my terminal and type -- everything's all warmed up and on the air. In many cases you can extend you range by going through existing duplex 2m FM repeaters; some of us do this now in the San Francisco area. It's not optimal, but it often works. The problem of how to link into the existing National Traffic System is being worked on. Suffice it to say that we aren't there yet. The currently implemented approaches are, unfortunately, "think small" approaches, and we still lack a good model of what such a system should look like on a national scale and what its high-level protocols should be. There are some systems in place now that provide a limited capability for NTS traffic passing via packet, mostly in the Northeast; they suffer from the disadvantage of being utterly ad hoc but offer the advantage of giving people exposure to the idea of traffic-via-packet now. (Admittedly an opinion, but I design and build distributed artificial intelligence systems for a living, so I allow myself the luxury of holding such an opinion.) Some of us here on the west coast (emergency comm people, traffic handlers, and packeteers) are working on a general solution to this problem that can be implemented on a national scale. (Anyone who's interested is more than welcome to participate in the design process, by the way; there are a lot of hard problems to solve before we're all linked together -- it's not just a matter of more repeaters and more mailboxes -- and we need all the good networking ideas we can get.) Good luck & 73, Andy N6JLJ AEC, Palo Alto Red Cross