Portable data carriers are known for different applications, for example as so-called smart cards for bank transactions or for access control or for combined applications. For the various applications different subdivisions of the write/read memory in the data carrier are required so that given zones...http://www.google.ca/patents/US5467081?utm_source=gb-gplus-sharePatent US5467081 - Datacarriers with separate storage of read and write-inhibited memory locations
