So I have an MSV11-QC (the 4gb Q Bus memory board) that has a failed bit. On an 11/73 it throws the following error: Expected data = 125252 (1010 1010 1010 1010 Bad data = 121252 (1010 0010 1010 1010) Address = 10015140 Which puts the error in the top 2mb (1mw), bit 4000. No biggie, consulting the matrix at: https://gunkies.org/wiki/MSV11-Q_QBUS_memory Shows this to be bank 4, bit 4000 or E85. Cut out E85, popped the board in (to double check before replacing) and I see this: Expected data = 125252 Bad data = 121252 Address = 02015140 Ooops. That would be decimal 531,040 which puts it in bank 1? Which should be E88, where did I go wrong here? Or is the table for the MSV11-Q only valid for the 64k ones and not the 256k ones? If so the bits may be right, but the banks are different. Anyone want to cross-check this or my maths? Thanks! CZ