Answer: The standard operation of the AVME9660 is via the short I/O space therefor no jumper is required. Supports Short I/O Address Modifiers -Supports short I/O (A16) address modifiers 29H, 2DH (H = Hex). Short I/O space is used for all carrier registers and IP module I/O and ID spaces. The carrier board base address is set by hardware jumpers and decoded on 1K byte boundaries. Supports Standard I/O Address Modifiers - Supports standard (A24) address modifiers 39H, 3DH (H = Hex). Standard address space is used when an IP supports memory space. The carrier board is configured using programmable registers to set the IP starting address and size (1Mbyte to 8Mbytes). You mentioned that you are using this board in a system that uses geographical addressing, Are you aware that Acromag offers a VME carrier that supports geographical addressing - the model AVME9675.