Update on version 1.1 of the SBC-85 CPU board that just arrived—- Rather than tease out the build like I did last time, this time around I just did a full population, quick check, and then power up. Quite to my delight the prompt popped up on first power up. Lovely when that happens.
The smaller reset button was a good choice and the extra space between the barrel connector and the RS232 DB9 is nice. However, right after building the CPU board I populated a backplane and am bringing power from the backplane (since it has a switch), so I am not really using the extra space. Moving the power LED to the top of the board gives more of an impression that it is doing something, but I am starting to think that a heartbeat LED would certainly add a tiny bit of action and excitement.
There is one problem so far with this version– in the first version I just put in large round holes for the barrel connector but this time around I thought I would make the extra effort and modify the footprint to slots to better suit the flat terminals of the connector. Unfortunately, they did not render properly at the PCB shop so they are standard holes–way too small. The options are to cut a notch in the PCB for the flat terminals, only bring power through the backplane, or cut off the terminal from the connector and do a butt solder joint. On this board I went for the butt joint and it worked well, but I think cutting the slot is a better choice.
I am now exploring the board for any other mistakes that I made during the revision but, honestly, with the excitement of building the bus monitor looking for bugs in the CPU board has moved to the back burner. In addition to reverting the barrel connector footprint, let me know if there are other changes I should be considering.
