According to an embodiment, a control system includes a processing device; a main storage device to store the data; a cache memory to store part of the data stored; a prefetch unit to predict data highly likely to be accessed and execute prefetch, reading out data in advance onto the cache memory; and a power supply unit. The processing machine can be, for example, a machine tool, a production machine andor a robot. The first substrate is then removed and a second conductive layer is formed to complete a light-emitting device. The shield extends outwardly from the rear wall of the housing and surrounds the blades of the plug when the safety device is attached to the plug. Further, if there is a match, the credit card reader may allow the user to process credit card transactions through the credit card reader.