When users install the ACUCOBOL-GT Thin Client on a Windows display host, the ".atc" and ".acutc" file extensions are automatically associated with the thin client executable ("acuthin.exe"). As a result, when your browser downloads one of these files, it uses these associations to invoke "acuthin.exe". The thin client uses the contents of this file to establish its command line parameters. The thin client command line file has a format that resembles other Acucorp configuration files. The entries in this file are used to construct a command line. It may contain the following variables:
| Variable name | Description |
| atc-server | the name of the server to connect to (a required variable with no default value) |
| atc-port | the TCP port number to use (default value is 5632) |
| atc-runtime-options | runtime options passed to the runtime via AcuLaunch (no default value) |
| atc-alias | an alias that identifies a COBOL application on the server (a required variable with no default value) |
| atc-cobol-args | COBOL arguments passed to your COBOL program via AcuLaunch (no default value) |
The contents of the ".atc" or ".acutc" file are interpreted by the thin client as the following command line:
acuthin <atc-server>[:<atc-port>] [atc-runtime-options] <atc-alias> [<atc-cobol-args>]