Abstract: A set-up store is added to an intelligent data processing terminal for storage of terminal characterizing information therein. Terminal characterizing information includes a representation of installed terminal features and a representation of selected terminal options. The information is changeable by the operator to indicate new installed features or different selectable options.A system of interlocks safeguards against improper operator actions, as follows: An interlock prevents the entry of inaccurate terminal characterizing information. Another interlock disables normal terminal operation if terminal characterization information is not present in the set-up store. A security lock prevents unauthorized entry of terminal-characterizing information. An interlock disables operation of language-unique keyboard keys until a keyboard language has been entered. Another interlock prevents the selection of terminal options unless the installed terminal features are present in the set-up store.