This module is basically a 4:16 decoder with sync and async modes. In use, patch for signals to the 4 inputs and generate an endless variety of gate patterns. If nothing is plugged into the sync input, then the circuit will change when one of the 4 inputs is changed, with sync it will only change when the signal on sync is high.
IN 3: gate input
IN .09: gate input
IN -1: gate input
IN 56: gate input
SYNC: outputs change when the signal on SYNC is high.
Each outputs corresponding to a number from 1 to 16 (see picture of the pcb to see that numbers) and a gate is produced in the right output.
For example, if the IN 3 and IN -1 have a gate, you have the number 1010 in binary so the output 1010 light.