OK, well I think I got it working so that it waits for the push button to start, but then it seems like it keeps going even after the loops have completed. I will put in an LED command to signal when clocking is in progress and see what happens. It may just be that my calculations for transfer times are just off. I figured that at 3.6Khz sampling (which is how fast we would be sampling the real data), we could sample the data, do the A/D, and send the data off chip in about 2 minutes at 19200 inverted baud. Am I off in my estimations?