I've got a Williams manual covering the theory of Z Unit boards on loan from one of the WMS employees. I've scanned it to a PDF file of about 10 Megs but I may be able to get that down a bit with capturing text. Ideally I'd like to find a FTP site to upload this to & see that it gets a semi permanet home somewhere on the net. What is a Z Unit cpu? The first 34010 based board by Williams, Narc. As I understand it the theory relates to later board types too. Thanks, Kev