More clues definitely helps.
A big part of your problem Capn, is an error in the RDFs for URC-1056 extenders:
Code: Select all
EepromSize=$1400
...
AdvCodeAddr=$0C00..$19FF
...
BaseAddr=$0600
Note that the AdvCodeAddr specifies the end address is $19FF, which is beyond the EEPROM size of $1400. This is partially caused by an quirk in the way addresses must be specified in the RDF. All addresses must be relative to the start of the EEPROM area, so it is a common mistake to put the absolute address used by the extender in the RDF, forgetting to subtract the BaseAddr. In this case $19FF-$0600=$13FF
Try using
.
That should improve things significantly.
The extender writer should also double check the AdvCodeAddr and UpgradeAddr entries.