Recently implemented modifications to the computer processing of earthquake accelerograms are described. The main extensions to the system include dynamic instrument correction, robust band-pass filtering and accurate integration, all implemented in the frequency domain. The processed records now provide accurate representations of strong ground motion within the frequency band from 0.25 Hz to 24.5 Hz: full accuracy is maintained in the computed velocity and displacement signals. The use of the new processing system is demonstrated using two previously recorded accelerograms.