Blinking Light program for PDP-11

Tom> Hi Ashley, Did you get a response on your question? One point to Tom> keep in mind is that the various processor types behave slightly Tom> differently. The typical method used to do the "Cylon" lamp Tom> effect was to use the console switch/display register Tom> (777570). There are actually two basic approaches. The switch register one is used by RT11. The other one relies on the fact that R0 is displayed in the data lights when a WAIT instruction is executing. RSTS (and I think the other OSs) use that. Then there's the amazingly warped "fancy lights" option in RSTS, where both the data AND the address lights rotate -- in opposite directions. That one I'll leave as a challenge for the student. One hint: it's only supported on machines that have supervisor mode. paul