Memory with read-protected zones

摘要

The method involves defining a memory (10) as a number of zones, with each having its own code. When the equipment is assigned to a customer who has paid a particular tariff, the codes corresponding to the facilities which may be used are entered into the central processor and at each start-up are written to an erasable memory (38). The contents of the permanent memory (36) and the erasable memory (38) are compared by a comparator (40) and only memory zones with corresponding codes are made available to the user.