Modem Initialization Select-O-String

(and More)

Information Sources

Search Usenet News for Modem Information


Try the search services listed on this page:
http://ds1.internic.net/tools/usenet.html

FAQs and Other Stuff

Article in Byte
See the June 1995 issue for a review of V.34 modems.
Usenet News Group for Modems
news:comp.dcom.modems
V.34 Modem FAQs
http://web.aimnet.com/~jnavas/modem/faq.html
http://www.teleport.com/~curt/modems.html
RPI (Information from Rockwell)
http://www.nb.rockwell.com/modem_report/may95/ModemReport.html
Ask Mr. Modem (Initialization Strings)
http://molly.ipa.net/modem/
A Couple of Local (University of Georgia) Articles
V.34 (28800 bps) Access Coming to UGA
Installation of V.34 Modems

V.34 and V.FC Sounds

This is the sound of a V.34 connection at 21600 dialing 1800USHAYES
V.34 Sound (aiff)

This is the sound of a V.FC connection at 21600 dialing 1800USHAYES
V.FC Sound (aiff)

Modem Select-O-String

Following is a form which will build a custom initialization string based on your responses. The complete string will be mailed to, if you provide your Email address:

This limited selection is based on my experiences. Just send mail to me if you have additions, changes, or comments: bert@uga.edu

Modems Used

Hayes Optima V.FC 288 (to be upgraded to V.34), SupraFAXModem 288 V.34, and TelePort Platinum (V.34). (Others from memory that I used in the past.)

Extent of Liability

I assume no liability for, but not limited to, the complete destruction of your modem, your computer, or low birth-weight of your children if you elect to use the initialization string(s) provided to you via this form.

Speaker Control

Turn speaker on or off. Choose the "Off" setting if you have a spouse or significant live-in friend who hates noise. But seriously, there are more settings for speaker control. These are the extremes.
On Off

If speaker is on, adjust volume. The speaker must be on if this setting is to have an effect.
Low Medium High

Auto Answer

If you are going to be using your modem to dial-out only, set this to 0. This is the usual default, but not always. Any number between 1 and 255 will cause your modem to auto answer after the number of rings you specify.
S0=

Hanging Up

The selected value here of 2 (&D2) should hang up the phone when you issue a hang-up request through your communications software. A common default for many modems is &D0, which sets the modem to ignore the hang-up request. The &D2 setting is commonly preferred. However, if you are using Trumpet Winsock, see http://web.aimnet.com/~jnavas/modem/faq.html, and look for information on Trumpet Winsock and &D1.
&D=

Presence of Carrier Detect Signal

A common default modem setting (&C0) forces the presence of a carrier on, even though a DCD (Data Carrier Detect) signal has not been detected from the remote modem. The selected value of 1 here follows the DCD signal from the remote modem.
&C=

Escape Character

Even though you should not have to fiddle with this, your provider may not have disabled the escape character on his modems. (A crime for which he should be severely chastised.) S2 controls this character, which is usually set by default to a plus (+). The escape character is pressed three times (one second before and after) to switch to modem command state when online. You can then go back online with the ATO command. If your provider has not disabled this command, his modem drops to command state along with yours. Very bad, because you can't get back online. The S2 value below is for a $ sign (decimal 36). Any value greater than 127 disables the escape feature. BTW: The + sign is decimal 43.
S2=

Extended Result Codes

A personal favorite of mine. S95 controls the level of negotion information you see, including CARRIER, CONNECT, PROTOCOL, and COMPRESSION responses. Some modems have this S register set by default to 0, which provides little information (only a CONNECT message that indicates the DTE speed -- the speed between your computer and the modem). A value of 46 displays an extended set of messages, including a CARRIER response that reflects the DCE speed (the speed between the modems) and a CONNECT response that reflects the DTE speed.
S95=

Enabling or Disabling Error-Control/Data Compression


The "On" setting is actually &Q5 and the "Off" setting is &Q6. Your V.42bis modem will most likely be set by default with error-control and data compression enabled. However, you may (particularly when trouble- shooting) want to disable these features.
On Off

If you see an error, please your entries and type them in again. If everything is correct, your request.


bert@uga.edu
Page URL: http://www.uga.edu/~ucns/telecom/modsos.html
Last Modified: 21 January 1996