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A Telecommunications Primer

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A Telecommunications Primer

                            A Telecommunications Primer
                           =========================== 
Barton M. Bresnik                                          Coelho Middle School
bresnik@meol.mass.edu                                             June 29, 1995

Overview

     Telecommunications is a catch-all word for a variety of electronic media:
facsimile  or "fax"; transmission of words, sound, pictures, or other data
between terminals or  computers; voice mail; and newer services, such as "video
telepresence" conference. Here  are some connections you may make with a
computer and modem:

Someone to Talk to...

     Person-to-person calls allow communication with the hearing impaired and
provide  a permanent, unambiguous record of conversation. You may also use a
person-to-person  contact to play games such as chess, cards or aerial combat
simulation or to transfer data,  such as tax files to your accountant, or
vacation photos from your children.

     Local bulletin board services (BBS's) are a means to post and retrieve
messages, to  seek computer assistance or to meet people sharing your
interests. For example, the Zoning  Board in North Attleboro provides freeware,
information on various types of computers  and games, and a public forum. Local
BBS's are an ideal place to practice using your  system, as the "netiquette" is
usually informal and cost, zero. Just call the BBS and use it!

     Commercially operated or government maintained BBS's are often free (other
than  telephone tolls) and are designed to provide public or consumer
information. For example,  Canon provides a library of files to support theirprinters and NASA offers the SpaceLink  to disseminate aerospace news such as
enrollment information on Space Camp.

     Online services, such as America Online, CompuServe, Delphi, GEnie and
Prodigy  provide numerous services for a monthly fee. On GEnie, I regularly use
software libraries  to get programs for Atari, Macintosh and PC computers; send
e-mail messages both to  GEnie and to other users of other services; employ
Grolier's Online Encyclopedia for  research; use EAASY Sabre to check air
fares; read movie reviews, Reuters' news reports...  well, there are hundreds
of services available for the basic fee. These online services also  provide
access to the Internet, q.v. Other facilities, such as performing key-word
searches  of periodicals or making a stock market transaction, may have a
surcharge added (you're  usually warned beforehand of any extra cost). Some
online services charge extra for most  benefits: check the rate structure
before subscribing!

     Internet service providers are primarily devoted to getting you to the
access ramp of   the "Information Superhighway", but don't provide on-the-road
service. Some use a dial-up  account, over regular 'phone lines, to their
computers, which then connect to the 'net and  shuttle information back and
forth; you access their computers with a terminal emulation  program (usually a
DEC VT100 terminal) on your machine, while they operate Pine, Lynx  or other
software to talk on the 'net for you. Massachusetts Education On Line, .meol,
uses  this sort of "comand-line access"; I find it quite convenient. If you
want to see the graphics  and hear the sound effects immediately, though, you
need a high speed connection called  Serial Line Internet Protocol (SLIP) or
Point to Point Protocol (PPP) and a program such as  Mosaic. This may be
somewhat more expensive, as you need a faster modem, a higher level  of the
provider's service, and, often, a faster computer and a high speed "telephone"
line.  Certainly, adequate service may be provided by a dial-up, command-line
account from an  Internet service provider (or the more general online
services, such as America Online or  GEnie, which also provide menu-driven or
command-line accounts); you may upgrade to a  SLIP or PPP account if the
situation actually warrants it.

Paying the Tolls...

     There's no need to spend much for a basic system: almost any computer may
use  telecommunications software and a modem. If you're purchasing a new
system, consider:

Used IBM PC or clone, with at least a '486 microprocessor,
4 megabytes memory for DOS applications (or more RAM for
Windows applications) and VGA monitor:                       less than $600
Used Mac's are also a fine choice.
Modem:  new or used 14,400 bits per second (bps):            less than $100
         or new 28,800 bps, v.34 high-speed (the best)       less than $200
Telecommunications software: (freeware)                                free
Telephone line: use your normal telephone line                no extra cost

     Use virtually any computer you might have, but don't scrimp on the modem:
higher  speed makes use more enjoyable and also will save money in the long
run, as most services  still charge for the time connected, as does Ma Bell!
 
     Fees vary: a local telephone call to a BBS should be free; connection to a
local node  of an on-line service also is not a toll call. Some services may
need either a long-distance  call or a call through a low-rate network, such as
SprintNet, for a few dollars per hour. In  addition, online services and
Internet service providers have a monthly rate and/or an  additional hourly
rate. Some services may have surcharges for products which, from others 
providers, are free. To put this in perspective, my own monthly bill averages
$14, but a  friend, enamored of online games and chat, ran up a $300 bill over
one holiday!

     Note that you do not need a new or separate telephone service, though you
do tie  up the 'phone while the modem is actually running. By the way, disable
call-waiting, if you  have that service, while telecommunicating, by dialing
the code provided by the 'phone  company, or your telecommunications  may be
interrupted.
  Making Connections...
 
     Plugging the modem into the computer and an existing 'phone line may take
as long  as fifteen minutes, if you open the computer to install an internal
(card) modem. Setting up  software (a telecommunications, or comms, program) to
automatically dial a number and  log on with your password may take an hour.
Some online services, such as America  Online and Prodigy, require you to use
their proprietary programs, but these programs  often install themselves on
your system. Setup varies and goes beyond the scope of this  article, but a
setting of 8-N-1, local echo off is common [don't worry about these 
parameters; once set, you rarely alter 'em].

     There are commercial comms programs, but freeware or shareware offer a
chance to  use your system for little investment. These programs may be
downloaded from many  sources, or, to get your first program, I can provide
freeware.


Glossary


application         software or program 
ASCII               numerical code for transmitting letters and other
                    characters using seven "bits" [eight bits in extended-ASCII
                    format] per character: A=65, B=66...
baud                rate of data transmission (2400 is acceptable, but 28,800
                    is the best, today) 
BBS                 bulletin board system: post messages, send e-mail, download
                    or upload files, play games...
bit                 one binary digit: 1 or 0, on or off; one bit of information
bps                 see baud 
byte                group of eight bits; often used to represent one
                    extended-ASCII character 
capture buffer      record of your telecommunications session kept in memory;
                    very useful! 
COM Port            RS-232 port and the area of the Operating System to which
                    it reports. Due to IBM PC idiosyncrasies, the modem, which
                    may use COM port 3, could conflict with the mouse or other
                    serial devices! 
communications 
software            an executable file that enables the computer to "talk" to
                    modem and other computers. Also called "terminal program".

                    modem and other computers. Also called "terminal program".
cps                 characters per second, about one tenth the baud rate or bps
d/l                 see download 
download            receive a file, such as text, a program or picture, from
                    another computer 
e-mail              electronic mail; a message to another person or company
facsimile           "fax", sending a "photograph" of a page, with graphics as
                    well as text; some modems can also send and receive fax, if
                    you have the right software 
file transfer       u/l or d/l a file; ftp or http are a means to transfer
                    files on the Internet 
freeware            software that is cost-free 
ftp                 file transfer protocol; a pattern the software follows in
                    transferring files 
hypertext           text which contains "links" or cross-references to other
                    articles: just point at a highlighted word or phrase, and
                    the cross-reference is found! 
http                hypertext transfer protocol; accesses information by "point
                    and click" 
Internet            communications pathway started by the Department of Defense
                    to assure dispersed, redundant information storage,
                    processing and transfer in the event of national disaster.
                    This was given to education and industry, and has recently
                    This was given to education and industry, and has recently
                    been opened to commercial traffic.  
Kermit              protocol for file transfer; not as easy or quick as zmodem
link                within text, a pointer to other resources on the 'net 
Lycos               a browser to locate resources on the Internet 
Lynx                hypertext-based Unix program that allows PC's to access the
                    Internet; it actually is run by your service provider. 
modem               device that connects the computer to the 'phone line
parallel port       connection on the computer for data transfer; most often to
                    a printer 
online service      for a fee, provides software libraries, e-mail, Internet
                    access and many other services
public domain       software or files that don't claim copyright protection
serial port         connection on the computer for data transfer, one bit at a
                    time; used by modem;may be implemented over ordinary
                    telephone wire (twisted pair) 
service provider    the company, school or other entity connected to the
                    Internet over its high-speed data connection, which, in
                    turn, connects to your house via your regular telephone wires.
shareware           program which you may sample freely, but are expected to
                    buy if  you use it often!  
software            programs or applications which "run" on a computer  sysop   system operator     person in charge of the computer system 
telnet              using your computer as if it were actually a terminal
                    connected to a host system 
terminal emulator   program that imitates a "dumb terminal". All that vaunted
                    power in your computer is bypassed so that it simply
                    displays and records what's sent by  the modem. Most
                    commonly, an emulation of a Digital Equipment Corporation
                    model VT100, though VT52 and VT102 are also used.  
u/l                 see upload 
upload              send a file (text, MID, GIF etc.) to another computer 
URL                 Universal Resource Locator, i.e., ftp, http, telnet, etc. 
Usenet              bulletin board cum newsletter on the Internet 
Web Crawler         a browser to locate items on the Internet World Wide Web
WWW                 Internet sites linked by hypertext files and pointers
xmodem              moderately simple file transfer protocol 
ymodem              efficient file transfer for batches of files 
zmodem              easiest to use and very efficient file transfer protocol;
                    it will automatically put the files on your disk drive


Some Places to Call...

America Online  (800) 827-6364 x3507 (voice)                    online service
CompuServe      (800) 524-3388 (voice)                          online service
Delphi          (800) 365-4636 (modem), (800) 695 4005 (voice)  online service
GEnie           (508) 222-7550 (modem), (800) 638-9636 (voice)  online service
Internet Connection                     (508) 261-0383 (voice)  Internet access
IDS             (401) 884-9002 (modem), (401) 884-7856 (voice)  Internet access
SpaceLink       (205) 895-0028 (modem)          NASA (U.S. government) free BBS
Zoning Board    (508) 699-0599 (modem)                                 free BBS


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