Reproducing old machines with newer technology (Re: PDP-12 at the RICM)

It wasn't _just_ eye candy; it was a real help in problem debugging (when the machine was stopped), and you could tell a lot about what the machine was doing (when it was running) from the way the lights changed. When the overall machine cost came down, they were too expensive to be worth what they cost, though. Speaking of lights for feedback, anyone remember the 'run bar' - or whatever they called it, my memory fails me - on the display on the Lisp Machines? Actually, it was a series, IIRC - one for the CPU, one for the disk, etc. The machine didn't have LEDs, but it used short lines on the bit-map display instead. IIRC, the idea was copied from the Knight TV's on MIT-AI. (Which I believe were the first-ever bit-mapped displays - anyone know of an earlier one?) Noel