  ķ  ַ  ķ  ַ  ķ  ַ  ķ  ַ  ķ  ַ  ķ  ַ  ķ  ַ  ķ  
 ֽ  ӷ ӽ ֽ  ӷ ӽ ֽ  ӷ ӽ ֽ  ӷ ӽ ֽ  ӷ ӽ ֽ  ӷ ӽ ֽ  ӷ ӽ ֽ  ӷ 
ֽ ַ ӷ  ֽ ַ ӷ  ֽ ַ ӷ  ֽ ַ ӷ  ֽ ַ ӷ  ֽ ַ ӷ  ֽ ַ ӷ  ֽ ַ ӷ
  ӽ  Ľ  ӽ  Ľ  ӽ  Ľ  ӽ  Ľ  ӽ  Ľ  ӽ  Ľ  ӽ  Ľ  ӽ  
                
      ߱         ߱ ۱۱ ۱۱
                              ۱۱ ۱۱
                               ߱  ߱
                        
                                  
                                 ***  AND  ***

              
      ߱߱  ߱  ߱  ߱  ߱߱  ߱
                                  
                             
                               ߱
                                  
                
                        
  ķ  ַ  ķ  ַ  ķ  ַ  ķ  ַ  ķ  ַ  ķ  ַ  ķ  ַ  ķ  
 ֽ  ӷ ӽ ֽ  ӷ ӽ ֽ  ӷ ӽ ֽ  ӷ ӽ ֽ  ӷ ӽ ֽ  ӷ ӽ ֽ  ӷ ӽ ֽ  ӷ 
ֽ ַ ӷ  ֽ ַ ӷ  ֽ ַ ӷ  ֽ ַ ӷ  ֽ ַ ӷ  ֽ ַ ӷ  ֽ ַ ӷ  ֽ ַ ӷ
  ӽ  Ľ  ӽ  Ľ  ӽ  Ľ  ӽ  Ľ  ӽ  Ľ  ӽ  Ľ  ӽ  Ľ  ӽ  



Perhaps two notions best describe computer/modem
telecommunications:


                Ŀ
                          
                Addiction 
                  Ŀ
               Ĵ                  
                Mild frustration 
                                     
                   
                                
                                                   ۰
                   Did you say...                  ۰۰
                                                   ۰MILD?۰
                                                   ۰۰
                                                   ۰
                                                   ۰
                                                    





Modem communication can be the most addictive, useful, and
powerful application of a computer. It's a process loaded
with the need for patience and persistence. However, "No
pain, no gain!"

Computer telecommunications is the process of hooking two       <GLOSSARY 6 5>
computers together through a telephone line to exchange
files of information and programs or carry on live
conversations. Your computer will need a device called a
MODEM which allows data to be converted into a special          <GLOSSARY 15 18>
signal which can be transmitted over a phone line to another
computer.

                        There are two types of modems:


                          Ŀ     Ŀ
                           Internal  and  External 
                               



External modems are a bit more expensive than internal
modems because they have their own case and power supply.
External modems require a socket on the computer or port
(usually the serial port on the back of your computer.) The
serial port is also called a COM port, com for
communications.

Most PC's come with a serial port, a few must have it
installed.

If you are already using the serial port for something else     SERIAL DATA
like a mouse or joy stick) you may need an additional port      <RS232>
installed. You may be able to temporarily unplug the device     SERIAL PORT
using the serial port. External modems take up a bit more       <GLOSSARY 22 11>
space and add a bit more clutter on your desk (internal
modems are installed inside the computer.) Some people like
the external modem with its blinking lights which instantly
displays the call status. Another consideration is that
external modems are portable and can be moved from machine
to machine by simply unplugging the modem.





DEFINITIONS

The "host computer" is the one your PC is calling. Sometimes
this is a commercial service such as Delphi, GEnie, Prodigy,
or Compuserve which are large interactive services. Other
times the host may be another PC your friend is using on the
other side of town or perhaps a bulletin board system (BBS)
which is a computer operated for general public access by a
private individual or company with files and messages of
general public interest and access.

Another important term is baud rate. It is associated with
the modem transmission process. Baud is a reference to the
speed at which your modem and the host modem exchange
information. Some common rates are 300 baud, 1200 baud and      BAUD
2400 baud. You should obtain the fastest baud rate modem you    <GLOSSARY 4 2> 
can afford.

Most BBS systems will not even let you connect at 300 baud
any more.


A 1200 baud modem is roughly 4 times faster than a 300 baud     MODEM SPECS
modem. Since you may be transmitting information long           <MSPECS>
distances, speed, and brevity of the modem link can really
be an important factor.                                         HAYES COMMAND
                                                                SET
As an aside, a 2400 baud modem can be switched to transmit      <1200>
and receive at the slower 1200 and 300 baud rates so there      <2400>
is some "downward" flexibility in purchasing a high speed
modem which allows lower baud rates as needed.

The software which controls the modems, and computers
linking during the exchange will "synchronize" the two
modems, determine which modem is using the slower speed and
adjust the faster modem downward to that speed. Many BBS
systems use the 2400 baud rate and some are even capable of
9600, 14,400, or even 38,800 baud - in this case the BBS
host computer will slow to your rate.

If you plan to do much long distance modem work, a 2400 baud
modem, or faster, is the wisest choice. The higher purchase
price which will be offset by savings in reduced long
distance rates.









Next, take a look at the communications software. While DOS     TELIX IS THE
controls the internal workings of your computer, you'll need    BEST!
communications software to enable the PC, modem, and
telephone line to work together. Many "integrated"
commercial software packages have a communications package
built in or added as a separate module.

Shareware and public domain packages also exist. Some of the
more dependable software packages include:








                
                Ŀ
                        
                 Qmodem 
                        Ŀ
                    
                     Procomm 
                             Ŀ
                      
                          Boyan 
                                ͻ                         
                                                     
                              Telix                          
                                    
                             ͼ 
                                      Ŀ
                                       and   
                                        Ŀ
                                                             
                                                GTPowercomm  
                                                             
                                               





Good communications software is flexible and powerful           TELIX IS
without being hard to use. The best comm programs have help     THE BEST!
screens and tutorials. Telix, for example asks a few simple     
setup questions then attempts to set the numerical settings
needed without operator intervention or frustration.

Although obscure at first, the modem software setup process
allows you to configure the software package for your
specific PC and modem combination. The modem software needs
to be told which serial port (COM port...usually 1 or 2) you
will be using.

You will need to tell the software which directory or drive
where files will be sent (downloaded). The baud rate must be
set. You will usually have to tell if the modem is Hayes
compatible. Hayes compatibility refers to a standard set of
transmission instructions which many modems share.













A very good program for Telix users to get is T-FIG, The 
Telix Tutor.  This program is designed for beginners.  It
actually reads the Telix comm program's configuration and 
displays it in screens of text explaining what the items are, 
what they do, and what they need to be.




*   T-FIG is available from the author of this program.














Other basic details like PARITY, and DATA BITS have to be       <PARITY>
set. These refer to how the data is "grouped or packaged"
during the actual modem transmission. Generally data bits       DATA BIT(S)
are set to 8. Parity is usually set to NO. Commercial           <GLOSSARY 8 22>
services such Compuserve offer exception to these settings 
and will tell you these settings in their literature.












                              An example:

         If parity is required, set data bits to 7. Set stop    STOP BIT
         bit to 1. This is a total of 1 + 7 = 8 Bits. The       <GLOSSARY 23 17>
         final bit is usually used to check parity/accuracy.
         The above setting is cryptically referred to as 8N1    START BIT
         which means 8 bits, no parity, one stop bit. Don't     <GLOSSARY 23 14>
         worry about this too much. Often this is a one time
         setup. Once its done you can forget it.














Other settings can include ANSI standard terminal emulation     ANSI
(a standard selection you should check if given the choice).    <GLOSSARY 1 9>
ANSI terminal emulation is usually the default setting and
should only rarely be changed.

PROTOCOLS will have to be specified. The protocol is a          PROTOCOL     
method of checking for errors between modems as the data        <GLOSSARY 20 1>
transmission progresses. In a precise fashion, these
protocols tell the first modem to transmit a small packet of    XMODEM
data . . . then the receiving modem will play back a short      <GLOSSARY 28 11>
verifcation "checksum" or "password." The transmitting modem    
stops, listens for the checksum and if it matches the           YMODEM
information which was sent, the first modem transmits the       <GLOSSARY 29 9>
next packet of the message. This continues, one small packet
of information/data at a time. The idea is to protect data      ZMODEM
integrity over noisy, static-prone telephone lines.             <GLOSSARY 29 12>

You need a protocol for sending (uploading) or receiving         
(downloading) data. Several common protocols include Xmodem,    
Ymodem, Xmodem-CRC, and Zmodem.





Xmodem is generally offered by most BBS systems and is a
safe bet when you are not sure what to use. Other protocols
are somewhat faster and/or slightly more dependable, but
Xmodem will do the job. Trial and error or simply logging
onto the BBS system with Xmodem and then inspecting the menu
of other protocols available will give you more detailed
information and clues about other possible protocols.

Ymodem offers a faster transmission rate than Xmodem, better
data security through a refined CRC checksum method and
finally a method for "batching" or sending/receiving several
files one after another unattended.

Zmodem is faster still, somewhat more secure with respect to
data loss, likewise offers batch transmission of many files
and additionally allows a file to be partially stored if the    PARTIAL TRANSFER
connection is lost and then completed when the connection is    <GLOSSARY 29 15>
restablished so you do not have to transmit the entire file
again!





General considerations in selecting software for modem use
include:

*    The dialing directory is REALLY important. The idea is     
that the package will store and dial your most frequently       
dialed numbers. Some packages hold only a few, some quite a     
lot! Does the package store your individual password and
comments next to each number? What about linked scripts that
will run whenever a specific online connection is made? You
may wish to use different passwords for each BBS system you
call.

*    Transfer protocols offered. Xmodem is a basic, but you     
may want more efficient protocols later. Make sure the          
package supports several or can be upgraded to more
protocols later. Zmodem one is the best.











*    How are numbers dialed from the list? Will the program     
call back and continue trying if the number is busy? Can it     
dial numbers from the list in a certain order. Can it do
circular dialing (several numbers are called in a row, then
the program jumps from the bottom of the list and starts at
the beginning again - around and around in a circle)? This
type of dialing is important if you deal with busy
communications services and BBS systems where it may take
time and several calling attempts before logging on to a
system especially during the busy evening peak time.







*    Does the package offer scripts or macros? A script is a    
way of having the package automate several steps. Without       
further input the package can call a BBS system, type in
your name and password and then continue typing further
keystrokes as if you were entering them from the keyboard
yourself. Script capability is a programming-like language
which gives the communications software package a customized
way to enter many keystrokes while you only input one or two
strokes to start the process. Many programs let you even
record the sequence of keystrokes during a communications
session for playback and retrieval later. Beware though, if
the system which you are calling changes log on sequences.
You may have to go back and later revise your original
script. Not a major problem, but sometimes it can be a
hassle.

*    Does the program allow you to capture screen               
information to your disk drive? Can you send screen             
information to your printer? Long communication sessions on
line with your modem produce endless screens of information
which scroll by quickly. The ability of your software
package to output all or selected parts of your session to
permanent disk file or printer output can be a definite
bonus.






Local neighborhood BBS systems can offer the most
entertainment and information for the first time user. The
principal rule of behavior: "Act like you are in a good
friend's home." Courteous behavior is a must. How do you
find telephone numbers for these systems? Consult local
computer clubs for a few numbers for BBS systems and then
call the BBS systems with your modem for lists of MORE local
telephone numbers. BBS operators and users are quick to
answer questions for new users and can serve as helpful
"experts" on any computer question. Operators of these BBS
systems are frequently called Sysops and many provide BBS
systems as a hobby activity much as other hobbyists enjoy
short wave radio operation.





Most BBS systems will allow you to tour within the various
activities and parts of the system for 30 minutes to an hour
on your first call. After that you are expected by some
"boards" to leave your name and a phone number where you can
be reached for verification. Some boards are free, some
request a nominal use fee (usually around $25 per year.)
Some boards request that you upload (send to them via modem)
shareware files or public domain software in order to
download their software. The process is something like two
kids with baseball trading cards: "I'll trade you 225,000
bytes of this shareware file for 250,000 bytes of your
files."

You usually are allowed access only to certain "low level"
(but interesting) areas of the BBS "board" on your first
visit. The Sysop (system operator) may be available to come
"online" if you experience difficulty. The software of the
BBS system itself will safely keep you from damaging the
host computer even if you hit an incorrect key or enter a
wrong command. You may leave messages for the Sysop, leave
messages of a general nature, ask for help on a specific
question, download public domain software, play a game, or
just generally explore the information within the system of
the host computer.





Downloading files is easy. For many boards the command is a
simple "D" for download. The BBS will ask you the name of
the file you wish to download and then give you an estimate
of how long it will take and the modem protocol you will (or
should) be using. After that you key in a keystroke or
combination which tells the software in your computer to
begin the process. When the transfer is complete, the host
BBS takes over and presents the main menu of choices or
selections.

Lists of phone numbers for online services and BBS numbers
are available from most of the boards themselves, local
computer club newsletters, and many computer store
salespersons.









Most public domain and shareware software from BBS systems      SHAREWARE
is stored and transmitted in a compacted form called an         <GLOSSARY 22 20>
archive (ARC, ZIP. PAK, or LZH format). You will need a
small public domain or shareware program also available from    
the BBS board to unarchive (unpack) the software. This          
archiving process is done to compact the software for
shorter, more efficient transmission. It saves time and disk
space for both the BBS and you. The easiest way to visualize
arc'd or zip'd software is to think of the many files of a
typical software package compacted in size and then placed
into one single file. You might also wish to compact your
other files for storage on a hard drive aside from the modem
process. File compaction is a useful tool all by itself!
PKARC, PKZIP, PAK, and LHARC software are shareware packages
available from BBS systems.














Working with modems and telecommunications software sounds
mysterious and intimidating at first. However, it is a
thoroughly enjoyable and rewarding hobby. It's also a nice
way to make friends and explore more deeply the global
network of information and friendships.

