Abstract: The validity of a code, such as an alpha-numeric code, constituted by a series of elements and including a checking key corresponding to the digit value of the first element of the code, is checked by a memory including an addressable dual-input table having a number of rows at least equal to the maximum number of elements of the code and a number of columns at least equal to all the possible numerical values of the code element. Columns and rows of the table are respectively addressed by the numerical value of a code element and by the relative position of the code elements in the code. The location defined by the intersection of the addressed column and row contains an entry for a remainder resulting from division by a given modulus of the numerical value of the code element multiplied by a coefficient assigned to the position. Each element of the code and the corresponding remainder contained in the location of the memory addressed by the code element are read by a processing means.

Abstract: A control arrangement for a belt printer having characters arranged in successive series on an endless belt and passed continuously in front of a print support and hammers adapted to be actuated by a control device. A recording store is connected to a calculating unit and records information relating to each character to be printed along a line on the print support. A scan register contains information relating to the coincidences between the characters and the striking members at any given time. Information corresponding to the condition when a predetermined character is to be struck by a given hammer in the course of a given scan, is stored in a storage member along with information indicative of whether or not the predetermined character is repeated in the series of characters.

Abstract: A high speed printer receiving line-by-line character data from a computer employs a number of sets of hammers and a belt carrying a number of sets of characters. The belt travels continuously past the hammers and the spacing between characters is greater than the spacing between hammers so that, during one cycle in which all characters of a set have passed successively into alignment with a given hammer, there are a number of scan cycles in which a number of different hammers (one from each set) are aligned with characters a given number of successive subscan times, where the aforementioned number of scan cycles is equal to the number of characters in a set. Thus, the designation of a particular scan cycle for any given hammer uniquely defines the character which will be struck by that hammer during that subscan uniquely related to that hammer.