Oooh, thanks; I had that image, wasn't exactly sure what it was. I hadn't done much with the PDP-15 panels, in part because it wasn't my focus (the -11) panels, in part because it seemed like there were a ton of them, in the -15 pictures I had. I have now put a few cycles into them, and have identified the RF11 and TC11 as well, and added them to the page (crummy images from scanned manuals, though). There are still some other -15 panels showing up in pictures, which I have no idea about. To start with, there's this image: http://homepages.inf.ed.ac.uk/gdmr/Historical/Photos/1980.08-PDP1540.jpg That's clearly an FP15 on the lower left, and I have identified the center one as a TC15, but what are the other two? And here's one with two _more_ different panels: http://www.simulogics.com/nostalgia/DEC/15_01.jpg The one on the right does _not_ seem to be a TC15... And then there are: http://www.chilton-computing.org.uk/gallery/ral/orig/r12600y.jpg http://www.chilton-computing.org.uk/gallery/ral/orig/r12588.jpg but those seem to be the same as in the first one. Noel