So, the CHM has an RSTS-11 brochure: http://archive.computerhistory.org/resources/text/DEC/pdp-11/Digital.PDP-11… which shows in a couple of places (front cover, page 6, 7, 10, 11) an indicator panel which I haven't been able to identify: it's the one where there are four full-length light rows on the left, and the lower right row of lights is broken up in the three groups - small, large, small. (The other indicator panel is known, it's an an RF11). I have been searching for these panels for quite a while now, and have a page for them: http://ana-3.lcs.mit.edu/~jnc/tech/DECIndicatorPanels.html _but_ ... I have never seen that panel. I am quite sure that it is _NOT_ an RK11-C panel; although no image of such has ever been found (I think because it was never produced - no DEC manual or print set refers to it), the RK11-C prints show the wiring for the connector to the indicator panel (which would presumably have been a standard DEC 19" x 5-1/4" panel of the kind documented on the page above), and from that it's possible to predict what it would look like, as shown here: http://ana-3.lcs.mit.edu/~jnc/tech/pdp11/RK11-C_inlay.txt http://ana-3.lcs.mit.edu/~jnc/tech/pdp11/RK11-C_inlay.pdf Can anyone shed any light (no pun intended :-) on what this is? The RF11 engineering drawings list (on page 187/188) all the inserts available (as of that date) for the standard 19" x 5-1/4" indicator panel, and I don't have pictures of all of them, so it's possible this is one of them. (It's clear from the brochure that this wasn't necessarily a working system, since it appears in a number of different configurations. So maybe they just grabbed up a random indicator panel and plugged it in to make the system look cool.) One possibility is that it's a prototype that was never produced - or perhaps it was the indicator panel for an earlier RK11 controller (although I can't find any mention of an RK11-B or RK11-A, and the list above doesn't contain an RK11 entry). Anyone have any ideas? Noel