Hi I made good progress today. I got the programmer working again. I'm now doing 2716s on the PB-10 again. I blew some more test code and also figured what the problem was with the controller. Previously, I'd gotten the frequencies change in the crystal and PLL circuits. I got to the point that it appeared to be reading the disk into the USART chip but not getting data into the dual ported RAM. It was still erroring on the header. I wrote code to ignore the header and tried that. It still seemed to be missing the header data. This is when the programmer decided to cause problems. While waiting to get parts I realized what the problem was with the controller. I was running everything from the memory window in the Poly88s monitor. Every time it updates a single byte, it rereads a large block of memory to put into the display. I was pointing to the RAM that was double ported and this stole cycles from the controllers time. This caused missed bytes from the USART. I wrote some simple code in another area of memory and used that to initiate the read command. It was then reading the header and data without missing any of the header or data. I expect I'll soon make greater progress. I need to delay some before reading the double ported RAM or the controller will miss the first few bytes. I need to write my serial transfer and finish the code for reading the sectors. Dwight _________________________________________________________________ Shed those extra pounds with MSN and The Biggest Loser! http://biggestloser.msn.com/