How do I change the time signature?

You can change the time signature while the device is playing or stopped.

Press MAIN and TEMPO together. Use knobX to adjust the numerator (beats per bar) and knobY to adjust the denominator (note value that gets one beat).

The time signature affects how your patterns are counted and displayed, but won't automatically change your existing pattern lengths. You'll still need to adjust pattern length separately using RECORD + PLUS or MINUS if you want your bars to match the new time signature.