A self-propelled device is provided including a drive system, a spherical housing, and a biasing mechanism. Context administration can include setting up and maintaining subject data definitions, intervening in context manager operations, providing security functions to protect sensitive context information against tampering by unauthorized users, etc. The device receive memory is partitioned into blocks which are further divided into free list and allocation list. When a current time of the electronic device matches an alarm time of an alarm clock, the electronic device detects whether a user of the electronic device is awakened by determining whether the first average acceleration value, or the second average acceleration value, or the third average acceleration value is greater than a predetermined value. A release mechanism causes the pair of rollers to stop urgingly sandwiching the card therebetween. This can be used for the manufacture of electroluminescent devices, in particular multicolor electroluminescent devices.