The following links are some of the better references I have found for modem initialization strings on the WWW. Currently they are not organized with much thought, and many of them duplicate the efforts of others. However, if you are struggling to get your SLIP connection configured using Trumpet on the PC or MacSLIP on the Mac, you may find the initialization string you are desperately looking for on one of these pages.
As time permits I will try to get back to this and add some commentary, recommendations, and possibly even some colors and graphics to make it a bit more aesthetically pleasing. Until them, I hope this proves useful to someone!
Internet Indiana's Modem Setup InformationAdditional Modem Initialization Strings For Trumpet Winsock
Modem Initialization Strings for Trumpet, Chameleon and Microsoft SLIP/PPP
Modem Initialization Strings
Internet Starter Kit for Macintosh Modem Page