(Windows only) ATECFG is a wrapper for the Windows program, atecfg.exe, which is installed along with A-Shell/Windows and which allows you to add or edit "ATE configurations". ATE (A-Shell Terminal Emulator) is a facility that allows you to turn your A-Shell/Windows session into a client connected to another machine, over serial or network (telnet) links. It is invoked via TELNET.LIT.

In order to use TELNET to make a connection to another machine, you must first define a "configuration", which is a collection of parameters describing the connection. Such configurations are stored in the local Windows Registry. The parameters are reasonably self-explanatory to anyone familiar with telnet and serial connections. See the discussion on TELNET for more information about ATE.