Abstract: An IC card has a CPU, a first memory for storing a test program, a second memory for storing an application progam, a bus connecting the CPU and the first and second memories. A detection circuit for detecting whether the CPU has began executing the application program stored in the second memory, and a disconnection circuit for disconnecting the first memory from the bus when the detection circuit detects that the CPU has begun executing the application program. The above-described arrangement makes it impossible to access the test program in the system ROM from the application program thereby preventing the occurrence of incorrect access.

Abstract: A method of organizing time sequential application data in an IC card, and an IC card having a structure for organizing such time sequential data. The IC card has an onboard microprocessor and an onboard semiconductor memory. Information is recorded in addressable application blocks defined for the purpose of receiving and recording application data. So long as unrecorded information blocks remain available, new application data is recorded in time sequential locations in those blocks and a record is kept of the sequence of recordation along with the block address at which the data is recorded. When all of the application blocks are filed, the last mentioned record is searched to determine the oldest data recorded in an application block, the new data is overwritten over that data, and the time sequential record updated.

Abstract: An information recording system utilizing an IC card having an onboard microprocessor, an onboard semiconductor memory which can be accessed from outside the card only by way of the microprocessor, and an onboard mass storage device also accessible from outside the card but directly rather than through the microprocessor. The mass storage device can be a mass storage magnetic recording media or preferably an optical storage device, and provides a relatively inexpensive information storage media for large amounts of data. The semiconductor memory stores information which is necessary to properly access the information in the mass storage memory, and outputs that information to an associated interface unit only by way of the microprocessor. Thus, address or encryption information which is stored in the semiconductor memory is secure because of access being limited by the onboard microprocessor, and securing that information makes more secure the information stored in the mass storage device.

Abstract: An IC card particularly adapted for multiple functions and having an error checking capability which operates within the card and without the need for the processing power of the terminal. The IC card has an onboard memory and an onboard microprocessor. The onboard memory contains a plurality of application blocks to which access is selectively allowed by the microprocessor and a protected block which is accessible by the microprocessor but inaccessible by the terminal. Stored within the protected block are data specifying the location, size and application associated with each of the application blocks, as well as an error check code relating to the data then stored within the application block.

Abstract: A memory device for detecting and correcting errors in stored data includes a circuit for generating an error-detection/correction code with respect to data to be stored, a memory cell array in which the data and the error-detection/correction code are stored, an error-detection/correction circuit for detecting and corrrecting errors in the data by using the error-detection/correction code when the data is read out of the memory cell array, and a function test circuit selectively and directly connected to the error-detection/correction circuit for testing the error-detection/correction circuit.

Abstract: A device for effecting personal identification which can be used in automatic teller machines, etc. is disclosed. The device utilize a portable memory medium, such as an IC memory card, which stores guidance information together with a personal identification code; when the medium is inserted into a fixed terminal of the device by the holder of the medium, the guidance information is displayed on a display of the device and helps the legitimate holder of the portable memory medium to recall the identification code correctly. The memory medium may store plural pairs of such personal identification codes and the corresponding piece of guidance information. In such a case, one pair of the code and guidance information is selected in each instance of identification, so that abuses of the memory medium by strangers can be prevented effectively.

Abstract: An IC card having a built-in microprocessor, a fixed program memory with an extended program memory section, and a programmable memory with an extended programmable memory section. An external program can be temporarily loaded into the extended programmable memory section through the microprocessor under the control of an operating program stored in the extended program memory section. Such an external program may be a test program for checking the functionality of the IC card. The test program once loaded into the programmable memory is preferably erased after execution by the microprocessor so that an unauthorized person cannot easily access data or information stored in the memories from outside the IC card, thereby improving the security.