Stan, Your description of the "A" comparator of the 339 got me on the right track! I re-read the datasheet on the operation of the inputs and with the help of your description, swapped a couple of wires around on the BB and the circuit is now working! Thank you for the explanation, that is exactly where I was getting confused.
The PRR signal with just a couple of relays is looking nice! I'm sure there is a little more to it, but using only 2 relays looks a bit more appealing than getting all those little jumpers and components in the correct holes going to the correct IC pins on the BBs. But then you don't get all the excitement of trying to get all the little wires in the incorrect holes to the IC pins and related head scratching (maybe excitement isn't exactly the correct word...).
GRJ, I'm working toward that, one of these days! It does sound quite interesting to be able to do what you describe. I got the MPLAB X IDE loaded as well, just haven't gotten around to trying the programming part yet. I also have some of the PIC chips you listed in traffic light thread, I think it was that one anyway. If memory serves, I think I even found the PIC chips in DipTrace right after I got them.
Those darn IC circuits keep de-railing me...but pretty good learning experience there too. It's all quite enjoyable to me as well.
