When you install the expansion board, the Mk2 original memory needs to be removed from the main board to stop capacitive loading of the memory bus.

The boot loader for the 2 (this is according to my memory of what Hugo said in a pub when we were all a bit well cut) expects a different size memory block than that of the expansion board (the 2A has a modified bootloader which expects the correct size). It will then fail to boot as it has initialised the memory map incorrectly.

The correction is:

- add a jumper to the mainboard to remove write protect from the protected bootloader address range
- blow a new bootloader with the correct memory map
- remove the jumper

The problem with this is that Hugo will have to write a new bootloader. He's getting married this w/e. Forget it for now...