An electronic cash register, which is so constructed as to print particular dates such as those of "off" days (i.e., business holidays) and bargain days of the store on the receipt to be issued. The particular dates to be printed on the receipt are previously memorized in a memory, and at the time of the issuance of the receipt, specific dates to be printed on the receipt are determined from the memorized particular dates and the current date.

There is disclosed an information retrieving apparatus with an external memory such as a magnetic disk capable of rearranging information stored in memory. The apparatus is provided with a first memory for storing at least accessing data. A comparator comparts the data from the external memory with the accessing data. A second memory stores the retrieved pertinent i.e., data resulting from a comparison of the accessing data with data retrieved from the external memory. The retrieved pertinent data is supplied as retrieving data to the first memory in synchronization with the data transfer rate of the external memory to enable extraction of plural records from the external memory.

Data comparisons are carried out between reference logical entities and logical entities proceeding from a file. The reference logical entities of different types are stored vertically in different horizontal zones (A, B, C) of a table in the order in which the entities of the same type are found in the file. In a control memory are recorded, line by line, items of control information relative to the comparison to be made with the reference entities of the zone of said table which corresponds to the line, items of storage control information and items of information for control of operations to be carried out at the end of comparison and/or storage, in particular the linkage of the processes to be carried out. The memory is read line by line while the logical entities from the file are received for comparison.

Encachement apparatus comprising a plurality of frames which include registers for storing data, one of which frames is selected as a current frame, the encachement apparatus responding to a key for outputting data from the registers in the current frame. The current frame is selected from a succession of frames and during a call operation a new current frame is selected as the frame following the current frame and during a return operation a new current frame is selected as the frame preceding the current frame.

All the combinations of upper-level parent parts and lower-level child parts constituting parent-to-child relationships in the structure of the parts are registered in a predetermined file in advance. When an arbitrary upper-level parent part is designated, all the child parts which are associated with the parent part are extracted by referring to the file. It is then determined whether a combination of parts including each extracted part as a parent part is present or not. If it is present, the referring operation is repeated again by setting each extracted child part as a parent part. When it is determined that a combination is not present, a corresponding child part is output.