A diode based presentation device comprising light emitting diode segments (D1-D7), by means of which characters are presentable, is, for permanent programming, connected to current generators (I1-I7) and, for reading, connected to current limiters (R1-R7) for limitation of current through a diode segment. For permanent programming, a character to be written in the memory is selected. The segments which are not used in the presentation of the selected character are eliminated by driving a current, which is at least as high as a current destructive to said diode, through the selected light emitting diode segments (D1-D7) in order to destroy the diode segment and cause an electrical interruption thereat. When reading, all the segments of the presentation device are energized with a voltage corresponding to the working point of the diodes, whereby the stored character is presented visually via the light emitting diodes (D1-D7) and electrically as a signal which is readable in connection to the current limiters (R1-R7) associated with each segment.
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