We now have the artwork practically finished for this board. A few final things needed attention. One is the backup battery. This board has a real time clock that runs all the time and so it places much higher demands on the backup battery. We have opted to use a much larger CR type battery than is usually used for Bally MPUs for example.
This also meant I had to source a holder for the new battery and then design up the footprint to add to the PCB artwork.
This is now all done so a bit of final checking and the art can go off to the PCB factory. I am also investigating FRAM to eliminate the need for the battery completely. It will all come down to the cost. It is my intention (at this stage) to offer the board complete BUT less the *micro, ROM, RAM & PLCC* as these can all come from the original board and are rarely damaged by corrosion. This will keep the cost of this board as low as possible.
This pic shows the larger batteries and holder along with the only SIP (Single Inline Pin) resistor network used on this board:
