OK - a quick update on this project.
We have completed the PCB layout and are currently spending a huge number of hours checking every track to ensure the layout is accurate. I have been caught out having boards made previously so I am always very reluctant to have PCBs made without having the actual parts in stock to make them with - it saves nasty surprises later!
Here you can see the TACT switches that will replace the obsolete 'red' test switch on the board:
Also the CR2032 battery holders arrived and we have confirmed the position and correct location for them. We have incorporated a schottky (low forward voltage drop) blocking diode into the circuit and it can be fitted if the board constructor chooses either the off-board AA battery pack option or the on-board CR2032 option. There is also a two pin header with a shorting link that can be used as a memory battery disconnect when working on the board - especially around the RAM.
We have also added many more words to the board denoting what certain pins connect to etc (left pic). Also, after carefully reading some of the common problems as outlined on Clays Pin Repair pages we also improved several areas. The picture on the right shows how we have added the ground connection to both upper and lower board traces to improve the grounding of these pins and you can also see in that picture "C5" and "C5B" - 5B is to allow for modern single ended electrolytic caps to be used in place of the (hard to find these days) axial style caps:
We are pretty well on time with this project and at this stage expect finished boards to be available end of Feb or early March.
