The CPU Board, 1400-5C, Part number PCB-0030, is the Central Processing Unit of the CNC control. These CPU boards came with 38Kb of battery backed memory which is used to store CNC Part Program, Tool Data – both Length and Diameter, Fixture Offset Data, SETUP parameters, and Backlash. Later Fadal added 4mb, 8mb and 16 mb. of expanded memory. To buy CPU Board, 1400-5C, New PCB-0030 vi... https://itscnc.com/circuit-boards/pcb-0030.html