An address space field is used in conjunction with a normal address field to allow indication of an address space for the particular address value. In one instance, one address space value is used to indicate the bypassing of the address translation used between address spaces. A different address space value is designated for conventional operation, where address translations are performed. Other address space values are used to designate different transformations of the address values or the data. This technique provides a simplified format for handling address values and the like between different devices having different address spaces, simplifying overall computer system design and operation.