In addition to performing some primary function, a digital computer can be simultaneously used as a bi-directional scalar to count pulses from several incremental digitizers. This may be achieved with relatively little loss in available central processor time by using a hardware option called 'memory increment'. The 'up' pulses from a digitizer are counted into one dedicated memory location while the 'down' pulses are counted into another. When the digitizer is in operation, the two locations are continually incremented and, because they are never reset, overflows occur repeatedly. A simple and fast algorithm is given to correct for these.