Communications Toolbox SDK Summary: The Communications Toolbox SDK contains: The Basic Connectivity Set 1.1.1 folder contains CTB tools, including  XMODEM 1.1 Tool  Serial 1.0.2 Tool The AppleModemTool v1.5.1 folder contains the latest version of the Apple Modem Tool, including developer documentation. The CommToolbox 1.1 folder contains the latest interface and library files needed for building CTB 1.1 savvy tools and applications. The Communications 1 folder contains the 1.0.2 installer script for installing the CTB 1.0 resources on system 6.0.x machines. The 1.1 script does a live install, and does better error checking on the system software. There are no differences between the CTB 1.0 resources which the Communications 1 v1.0 and v1.1 disks install. The CTB team recommends, however, that developers update their products to include the Communications 1 version 1.1 software. NOTE: Developers should do all new development with Open Transport where possible.