You should indeed have activity on the address lines, take another look as the machine comes up, they should be toggling, even briefly. Could be that data lines are stuck, and/or it is getting a halt somewhere. Another trick would be connect a 1k to +5, and touch it to the reset line, you should see the address lines blip a little then. If they never change state the processor is dead or the mux buffers stuck (74245's?) . If you can build a little proto board to plug into the processor socket so you can disconnect the address lines from the board, you should be able to 'free run' the processor, and see activity. If those address lines dont toggle with clock, power applied and reset low, I would suspect the processor. Randy