Abstract: A system for the nonvolatile storage of data, such as a postage meter system, employs a microcomputer coupled to two nonvolatile memories. The first nonvolatile memory requires data be applied to the nonvolatile data terminals for more than a predetermined time for data to be written into said nonvolatile memory while the second nonvolatile memory is of a type wherein data applied to the second nonvolatile memory data terminals for less than the predetrermined time is sufficient for data to be written into the second nonvolatile memory. The microcomputer operates under control of a program store to apply data to the first nonvolatile memory data terminals for at least a predetermined time under particular operating conditions and under other operating conditions to applying data to the nonvolatile memory data terminals and during the predetermined time to the second nonvolatile memory terminals.

Abstract: An electronically operated postage meter includes a non-volatile memory for the permanent storage of security and financial data utilized in the operation of the meter. In the operation of the memory, a standardized two-bit control signal is employed for providing read, write and word-erase commands in addition to one further command, namely, a block-erase command, wherein the entire memory is cleared. To avoid unintentional erasure of the entirety of the stored data, as might occur in the event of a fault in a control circuit or computation circuit coupled to the memory, a control-line translation unit is coupled within a control line which connects a memory control circuit with the memory. The control-line translation unit comprises a logic gate and a feed forward path, the gate operation being transparent to three out of the total of four control signals. Thereby, only the block-erase signal is translated, or converted, to a harmless one of the other control signals, more particularly, to the read signal.

Abstract: A postage meter system includes a nonvolatile memory and program store coupled to a microcomputer. Postage meter transactional accounting data records are stored in the nonvolatile memory. Each transactional accounting data record includes a header portion having piece count related data and a piece count data field. The most current stored transactional accounting record header includes piece count related data which differs from the piece count data in the piece count field. Other stored transactional accounting records have headers with piece count related data which are the same as the piece count data stored in the piece count field. In this way, the most current record can be rapidly identified. A ring buffer organization of nonvolatile memory locations are utilized for storing postage value setting prior to the commencement of a postage dispensing transaction.

Abstract: A system for the nonvolatile storage of data, such as a postage meter system, includes a microcomputer coupled to an MNOS type nonvolatile memory and also coupled to an EEPROM type nonvolatile memory, each memory having address lines and data lines. The address lines and data lines of the two nonvolatile memories are coupled to microcomputer ports such that the MNOS memory data lines are always at a high value whenever the EEPROM memory is addressed for the purpose of either writing or reading.The EEPROM nonvolatile memory control terminals and the MNOS nonvolatile memory control terminals are coupled to different ports of the microcomputer. Access to the MNOS nonvolatile memory is achieved by input/output mapping techniques. Access to the EEPROM nonvolatile memory is achieved by memory mapping techniques. In this way, protection is provided against inadvertently accessing the wrong memory or wrong address while executing read/write instructions to a selected memory.