Hi Dan, An amazing coincidence. I noticed today that you have written code for the 12C508 which you've got driving ISD's 33240 chip! I have just written some code for the 16C84 for that very part but I just can't get it to work. I have had others check my code and they can't see anything wrong. I would be forever in your debt if you showed me how you did the SPI interface emulation so I can see what I'm doing wrong. I find the manual a little vague concerning whether 16 bit commands are sent as all one string or sent as 8 bits then SS high then the next 8. I am really stuck so could I impose upon you to send me a sample of how you have handled this? Or, conversely, I could send you what I've written and you could point out where I'm blowing it. Given that you've already gotten yours to work, I defer to your judgement here. Either way, it would *really* help me out. --regards, Bill