Ah. That will limit the rate at which you can update the lights, though, right? I mean, you won't (be able to) update the panel after every word, will you? Although I suppose even if you only do it after each transfer, that's probably still going to give much the same visual effect. Ah, I was faked out by the illustration (not a picture, alas!) in the RF11 manual, it looked like they were grouped. I wasn't sure if the larger spaces between various fields were just bulbs they didn't wire up, or if they were also masked by the overlay; I just looked at some of my KA-11 overlays (now _there's_ a machine with blinking lights! :-), and they are indeed blanked in the overlay, so I would guess/asssume they did the same on the RF11. That sure looks like it. Too bad you don't have the overlay... Now that I think about it, I wonder if that panel was originally used on the KA? The 36 bits are certainly suggestive... I'll have to see if I can find a picture of the disk/tape controller display panel from the KA and see if that could have been it. Noel