Re: iMac to GS

[noone@nowhere.net]

Set up your IIgs and your Mac at their maximum baud rate to talk to the
modem from their respective ends.  The modems will negotiate for best
speed for 'talking' to each other, regardless of how fast they send
information to/from their respective PCs.

With much respect for others who have posted here, let me assure you
that the modem to modem works every time if your phone cord isn't
defective.  You do not need the telephone company, you do not need two
phone lines, just one good cord to plug the 'line' of one modem into the
'line' of the other.

Get into the comm program on both machines and issue an 'ATZ' command. 
This should cause the modem to send back to your screen either an 'OK'
or '0' (zero) message.  Failure to get this message means that your
computer is not really talking to your modem properly.

Go to the first PC, doesn't matter which one, and type 'ATX3D'.  This
command tells the modem to NOT look for a dial tone and to pick up the
phone line in 'initiate' connection mode and waits for an answer tone of
300hz.  (Would normally dial at this point.)

Go to the second PC and type 'ATA'.  This causes the modem to pick up
the phone in 'answer' mode.  (Would normally be initiated by the line
ringing.)  The modem then puts out a 300Hz tone to let the initiating
modem know there was an answer.  The initiating modem follows suite by
answering with a tone.  After that, the modems will 'negotiate' back and
forth to determine the fastest common carrier and compression to use
while talking to each other.  This can take up to a minute, wait for a
message of some type on both screens simultaneously.  Hopefully a
'connected' message.

Reasons why one modem may not talk to another and give you the 'No
Carrier' message are:
1. Modems not set up to allow enough time to finish negotiating.
2. Your modems have different 56k standards.
3. Your US Robotics modem is finicky.
4. You touched a key.
5. Modems are simply not compatible.

I have experienced all of the above problems.  All of which may be
solved if you have the book with AT commands for your modem, solutions
are fairly simple.  Just insert the proper 'command' into the AT command
before the A or D.  For the first issue, set your carrier drop delay to
a larger wait.  For the second, set the maximum speed to or 28.8 to
avoid the personality conflict.  For the third one, set the max connect
speed to 9600 for both.  For the 4th, just be more patient and wait for
the 'connect' message.  For the last, I've never seen this, ever.  

One last bit of advice on troubleshooting a modem connection problem,
turn on maximum verbosity and english instead of numeric responses from
the modem.

Hope this helps,
Ed

Side note: I am in the field of computer support and I have heard ISPs
give reason number 5. However, this has never been satisfactorily proven
to me.  One of the above most common reasons is almost always the case
and the ISPs are not willing to drop speed (custom set up) on one of
their modems and give you a direct line into it to get you connected.