TRIGGY is a sophisticated electronic device that accepts input from various types of sensors, including audio, photocell, manual pressure, microphone, digital port, and response buttons, and produces TTL digital output for each sensor input immediately after sensing a change in its state. The TTL outputs are precisely temporally linked to the physical inputs with minimal delay and jitter, making them suitable for use in triggering or event marking in behavioral and electrophysiological experiments. Triggy has many types of analog input, several modes of TTL digital input, several modes of TTL digital output, and several modes of serial input and output. TRIGGY is designed to be universally compatible with any experimental control software that supports a serial interface, and it is compatible with any physiological recording system that supports serial or TTL triggering.