He basically did super careful timing of the software to allow the main CPU to do the controlling. Because timing needs to be precise the software had to be pe

He basically did super careful timing of the software to allow the main CPU to do the controlling. Because timing needs to be precise the software had to be perfectly timed down to the cycle. Woz's designs were very tightly integrated with both software and the electronics, and he would use every part of an IC to keep the count down.