The program is menu driven, and the user should select a key-word from the current menu which is shown on the right hand side of the display screen. In order to do this it is possible to pick a key-word with a mouse or cursor, or the user can type in sufficient letters of the key-words in the menu to uniquely identify a command (frequently this is just a single letter). In this way it is possible to build up a complete command by making successive choices from the menus that are displayed without referring to the user manual.

Once the user is familiar with the command language the minimum abbreviated command may be used, and if the user is sufficiently confident, the display of the menus can even be switched off..

To cancel any command (whether complete or not) the user need only enter // or use the `ESC` key.