Since I've been failing miserably coming up with a working verilog PLL, I decided to do something easier tonight. I captured about 1,000 index pulses from a Sony MPF920-E(if I read date code right, it's from April 1997) with a 20+ year old floppy disk with a logic analyzer. I exported the data, and then massaged the data into some results with Excel. My average pulse was 200.487ms apart. All pulses were within 55us of each other, range was 200.464ms -> 200.519. Standard deviation was 9.46us. This sounds way way better than the NatSemi AN-505 note of 1-2%. Is anyone else surprised by this result? I was expecting differences measured in milliseconds not micros. Thanks Keith