At ResNova we have experienced a variety of problems involving three key factors: Modem Quality, Flow Control and Error Correction. We have the fortunate, but unfortunate distinction of being on the cutting edge- NovaLink and NovaTerm are the first telecommunication programs that truly use a Bi-Directional atmosphere. For NovaTerm to work reliably, hardware flow control and error correction are essential.
If you fail to achieve full flow control and error correction, you will not be able to connect or effectively use NovaTerm- even if standard telecommunication programs like Microphone or Z-Term work perfectly! We can't stress this enough!
Note:
One test that will show that even Microphone or Z-Term are not working effectively with flow control is to upload a file using a bi-directional protocol like ZModem. If you notice many retries (there should be none), then you have a flow control problem. Downloading will work fine with poor flow control.
Modem Manufacturers Unite!!!
Wouldn't that be nice? But since they haven't, and they effectively have ignored the Macintosh whenever convenient and especially ignored each other, every modem is different. If you have a poor quality, usually cheap modem ($200- $400), the modem may do odd things which result in adversely ended sessions or other annoyances.
We can't stress the need for a good modem enough!! We have evaluated virtually every modem on the market whose manufacturer has indicated an interest in supporting NovaLink, and have created the following list of recommended modems:
Hayes, Optima and Ultima
Telebit- Most models
AT&T- The more expensive line
USR Courier- Most models
Intel
Zyxel (for lower-end systems)
Now, assuming that you have a good modem, you may have problems in the following areas:
Drops Carrier
This is usually a result of a bad connection or lack of error-correction. New high-speed modems are very sensitive, and even the slightest imperfection in the signal can result in the modem "giving up". Lookup the AT command that turns on the best error correction your modem does, with fallback options. This will be in the manual. Write down the AT command, and use it in the expert setting modem string we will explain below.
Modem Connects, Submits password, and does not continue
past welcome screen...
This is a classic flow-control problem, and is the most common problem we encounter. The essential problem is that software flow control has been enabled on your modem. In order to avoid this situation, please follow these steps VERY CLOSELY:
A. Make sure you have a real flow- control (High Speed) cable. Ask around, call your
dealer, do whatever you have to do. If your cable is not proper, it will work with
everything but NovaTerm- but it isn't working on the other things as well as it could
be(the upload test mentioned above), so get a cable! ResNova sells them... call us
for information.
B. When you are positive you have a flow control cable, open the settings of NovaTerm
and do the following:
 
Set your speed to 19,200 and set the flow control option to "Hardware". This is necessary because with compression, the computer has to be speaking to the modem at 19,200, while the modem actually talks to the other modem slower. You do not want to hear the technical reasons for this, just accept it! If you have a few hours, someone at ResNova can explain it.
C. Now click on "Connect". If it does the same thing, or if you already did the above,
then read the next section.
Nothing seems to work- I am about to give up!
Well, don't! You must have a modem that is not recognized properly by NovaTerm and it is not sending the commands to turn on error correction and flow control properly. We will have to insert a custom modem string of our own. Do this by clicking on "Expert Settings" in the "Settings" dialog:
 
The modem commands above are for a US Robotics Non-HST modem. Note that they start with an AT E0 &D0- all strings should start with these.
This is where you insert the commands that NovaTerm will send to your modem. It's time to find your modem's manual or call the modem manufacturer. You are looking for two commands- Bi-Directional hardware flow control and error correction.
Modems usually default to error correcting properly, but they do not default to the proper flow control. Absolutely no other kind of flow control except for RTS/CTS Hardware (Bi-directional) will work. Sometimes it is just called CTS/Hardware flow control. It is often hard to find in a modem manual so calling the manufacturer may be the best bet.
All modem strings start with "AT EO &D0" The "AT" is necessary. The "E0" (Zero) turns the echo off, the "&D0" (zero) makes the Mac ignore a signal that may abruptly make it hang up. If you do not do this, you may lose carrier.
It still doesn't work
If you are sure that you have done all of this, and have called at least three of our modems at 379-9004, 9005, 9006 all the way to 9009, and you are still not connecting then there is a problem with hardware somewhere. You either have a faulty cable, or a modem that is not compatible with a variety of modems- which is very possible! Call us right away at 714/379-9000 and we will see what we can do. It will help if you fax us your modem's AT Command set summary in the manual at 714/379-9014.
