Abstract: The apparatus comprises a data storage provided with an electronic control unit to which are connected a retrieving unit, an input unit, and a charge/retrieve switch. The electronic control unit includes an input unit, an output unit, a program storage and a microprocessor. The data storage is provided with a number of preferably equal capacity storage cells, which are preferably divided into two groups, with one group forming a block storage compartment and the other group forming a sheet storage compartment. An indicator is preferably provided to indicate which storage cells are occupied and which are empty. When all those storage cells in the block storage compartment are occupied, additional information can be supplied to any empty cells in the sheet storage compartment, and vice versa. A display unit and a printing mechanism may be connected, through suitable switches, to the data storage.

Abstract: An identification card with interior circuits, including memory means, for use in a credit or identification system, into which the user enters a "secret" number and then the input gate to that part of the memory means is destroyed for security purposes.