Ok, So I thought i'd bring this all together and try out just a few more tricks before moving onto something more comprehensive. Having automatically identified the slot assignment and storing the value in zp SLOT $07 we can do some useful things with it Like retrieve and decode the status of the dip switches on the Super serial card.
This clock came out of Johns mid 70's Westfailia bus. When I had received it it was non operational though I was advised that an attempt was made to replace the two electrolytic capacitors as recommended on a website. This is where the adventure begins.