Multi-electrode electrical stimulation can serve several purposes: to deliver sensory input artificially, to modulate, or disrupt neural activity, and as a reinforcing or training signal. All of these were necessary for successful induction of goal-directed learning in vitro (Bakkum et al., 2008). The NeuroRighter stimulator is capable of stimulating with arbitrary waveforms from any electrode in a multi-electrode array (Figure 2). It improves on the RACS's 8-bit DAC by using the NI-6259’s 16-bit DAC, to produce very smooth stimulus waveforms with a wide dynamic range. Stimulus commands are generated in software, converted to analog signals by the NI-6259, buffered and monitored in custom analog circuitry, and directed to particular electrodes by a headstage-mounted multiplexor (Figure 1). The in vivo stimulator can be used in several different configurations: by itself (with no recording headstage), with recording systems from a variety of manufacturers, or with the complete NeuroRighter system. Further details of the stimulator can be found in Rolston et al. (2009a).