On Mon, 2008-07-14 at 16:47 -0400, Bruce W. Calkins wrote: > My book shows the 6845E in the parts list. > ~BWC~ Hmm, yeah, you're right. They mention it _several_ times - I need to go over this schematic in detail, the 'shadow' register might be a latch or somesuch. The schematic is, unfortunately, not all that clear. It'll make more sense once I get the board. C.