Subaru Repair: ignition module, spark plug wires, digital oscilloscope

Question
how can i check to see if the ignition module in my 1990 subaru legacy L is good or bad?  only two of my spark plug wires are sparking.  could this cause my car not to start?

Answer
You would have to have a digital oscilloscope or a meter that will read frequency to really properly test the ignitor.More likely would be a cam or crank sensor and again you need to be able to check frequency.Or if it died while driving maybe the t belt is broken