PURPOSE: To improve the reliability of character data and the redundancy of image data by adding a parity code for error check in case of the character data and inhibiting the addition of the code in case of image data.

CONSTITUTION: Interface adaptors 13a, 14a, 35a∼38a provided on respective equipments have the same specifications, the pin arrays of input/output timing and input/output connectors are interchangeable and any one of the adaptors can be connected to an interface connector 56 of a data capsule 50. Such kind of the interface means in connected to a certain information processor and data communication between the interface means and the processor can be executed by key entry through a key entry means. When the data are character data, an error detecting parity code is added to the character data, and in case of image data, no parity code is added to the image data. Consequently, the reliability of the character data can be improve and the redundancy of the image data can be also improved.