----- Original Message ---- Hi Nick, Assuming that you followed the 'Imsai Front Panel Usage' section in the referenced document, I would also take a look at S100 bus pins 54 and 20. I haven't touched any of my Imsai's in several years, but I do recall struggling to get a CompuPro motherboard working with the front panel. If memory serves, at a minimum I had to cut the trace leading to pin 54 (External/Slave Clear) on the front panel PCB itself. I noticed in the CPU-Z schematic that it is indeed driving pin 54 on the bus, so that may well be the issue. As for pin 20, it is GROUND in the IEEE 696 spec. I can't tell if the CPU-Z is driving that pin on the bus or not... if it is, you may want to cut the trace leading to it on the front panel board as well. I have additional notes re. another potential additional change that may be required (somewhere) ...I'll attempt to find them. In the mean time, I would try the pin 54 mod first, and then add the pin 20 mod if necessary. Scott