How does XP use the modem INI file?

[JH3]

Hi all,

Strange question, but how does the OS (XP in this case) use the INI file to control the modem? I see the init strings from the INI file getting sent to the modem, but I also see some other strings sent to the modem as well, eg an ATDT command prior to dialing, which forces me to place a P before the number dialed (since I do not have access to tone-dial).

I have found work arounds for most of my problems, but life would be simpler if I could change the sequence that the OS issues commands to the modem. Is this possible?

Cheers,

John

 

[pansophic]

As I recall, Windows has some of the basic modem configuration done under the Control Panel in the Modems section. I believe that you set the modem to Tone dialing there, so if you turned tone dialing off, it should default to Pulse dialing.

They do some of the Hayes standard features in TAPI, like the hangup sequence, dial sequence, ignoring dialtone, etc. I don't believe that they put any of that stuff in an INI file because it is standard across all Hayes compatible modems (and I believe that you'd be hard pressed to find one that isn't Hayes compatible these days).
pansophic

 

[JH3]

The DUN and modem settings which are available through Control Panel, etc., sometimes do not affect the modem at all (as in the case for Tone/Pulse dial for XP). I was wondering how TAPI, provided by the OS, interacts with a modem driver.

I have a dual boot system, Windows ME and Windows XP. Under ME, my modem works fine. However, under XP, there are issues (tone dialing is the default, no sound from speaker, need to set +MS=V90 via extra settings in modem dialouge box). The strange thing is, when examining the modem logs generated within either OS, they are nearly identical. The proper commands are issued (M1, for instance), and the exact same registers are being initialized (S0 and S7).

So I am trying to figure out if something might be happening behind the scenes, if the OS is somehow sending commands to the modem apart from the modem driver or INI file. Guess I will have to read up on TAPI, and figure that whole mess out. ugh.

 

[pansophic]

I'm not sure that reading up on TAPI will necessarily help, unless you can find a document that makes a distinction between the TAPI delivered with XP and the TAPI delivered with ME.

The way I understood it, and this may be completely wrong, was that TAPI provided a standardized set of outputs toward the driver, which interprets these instructions and constructs the proper instruction, which it forwards to the actual device. Otherwise I'm not sure how TAPI could interface with devices like Dialogic cards.

Out of curiousity, have you tried a compatible driver to see if it handles these things differently? Like a generic Connexant driver (if you are using a Connexant based modem).
pansophic