Abstract: A device for checking numbers consists of a multiplexer (101) with a controller module (106) linked to it. An output of the multiplexer is connected to a first input of a register (102), which is an element of memory, while a first output of the controller module (106) is connected to an input of a storage (103) and a second input of the register (102). An output of the register (102) and an output of the storage (103) are connected to inputs of the adder (104), which adds on its output a number, stored in the register (102) and a number written in the storage (103) at an address indicated by the controller module (106). The adder (104) generates on its output a carry-out signal, informing about overflow, which is passed to a first controlling input of the controller module (106), which manages operation of the device checking numbers.

Abstract: A set of printed circuit boards consists of a main board with at least one fragment intended for replacement and at least one replacement board, wherein said main board has openings in the dielectric layer placed along the edge line of the fragment intended for replacement, and between the openings there are bridges, and at least one of said bridges has an electric conductor thereon, and the replacement board has electric conductors in places matching the placement of the electric conductors of said bridges of the main board.