Abstract: In this patent, a timer-based recording scheme is developed to circumvent the internal delays associated with Flash based media when reading and writing from media such that the low level card access, rather than blocking the processor while writing to or reading from Media, uses a direct-memory-access (DMA) peripheral and then periodic interrupts (using an empirically determined period) to check whether write/read process is completed. If it is completed, then next write/read process is initiated. This process will be repeated until the recording is finished. At a higher level, to record in FAT format, the FAT table and Root Directory table are cached into the processor memory during initialization. Rather than updating those tables in the media, they are updated in processor memory (due to faster access times) while recording. Finally, those tables are written back to the media once recording is finished.

Abstract: A digital radio includes an identification number available only to the digital radio itself. A transmitted band received by the digital radio includes an identification number in an information channel. When the two identification numbers match, then the digital radio performs at least one function included in the information channel or, accesses a preselected procedure. In either situation, the presence of the matching identification number in an information channel results in the execution of instructions causing the digital radio to suspend operation, e.g., by deleting certain files. These digital radio can only be reactivated by the manufacturer, e.g., by the reinstallation of the deleted files. In this manner, the digital radio, being inoperative, is useless to a thief. In addition, one of the activities enabled by the identifying number in the information channel, when the digital radio is installed in a vehicle, can be the disabling of the vehicle.