dorner@pequod.cso.uiuc.edu (Steve Dorner) (10/11/90)
A while ago I posted about a problem I was having with the "Apple Modem Tool" and my modem, asking if there was a list of "proper" modem settings. I got no list of settings, but was able to solve my problem through the kind help of Byron Han and Tom Dowdy (thanks, guys). I'm not sure I'm happy about the solution, but that's another matter. My modem (a Multitech 224E) is an MNP-5 modem, which means it does error correction and compression. Because of the compression, the modem can deliver more than 2400 baud out of a 2400bps phone connection. I normally use a serial port baud rate of 4800 with this modem. Alas, this confuses the Apple Modem Tool. The modem tool tells the modem X4, which means it wants to see things like: CONNECT 2400 when a connection is made. When my Multitech makes a connection, it says: CONNECT 2400 RELIABLE COMPRESSED since the bit rate on the line is 2400. But the baud rate on the serial port is 4800, and remains 4800. The "Apple Modem Tool" fails to understand this, and resets the serial port baud rate to 2400 to "match" the modem rate, and communication stops. The fix? It turns out that you can customize the initialization codes for the modems. I was unable to find documentation on this procedure, but here it is: Select the "closest" modem to your own via the modem pop-up (for my Multitech, this is "Hayes-Compatible Modem"). Now, hold down the option key, and press on the pop-up again. A new item appears, titled "Custom...". Select it, and you get a dialog box that lets you diddle things. In my case, I changed the X4 to X0; this makes my modem say: CONNECT RELIABLE COMPRESSED without the "2400" that gets the "Apple Modem Tool" all confused. You could also avoid the problem by giving up compression and talking to the modem at 2400 baud, but that hardly seems like the way to go. I have so far not experienced any problems as a result of the change. -- Steve Dorner, U of Illinois Computing Services Office Internet: s-dorner@uiuc.edu UUCP: uunet!uiucuxc!uiuc.edu!s-dorner