Abacus is a module based on the legendary modules 257 and 281, offering a variety of linear, logarithmic, and exponential functions that can be either continuous or trigger-based. Abacus can generate envelope and LFO signals at speeds ranging from 25 minutes to 1000 Hz. The module also functions as a mixer/attenuverter for 4 CV signals, enabling the creation of delay, slew, and portamento effects.