>as far as I know, the PCI bus is little endian, even on big endian machines. >Is this true for RS6000 (44p/270) too ? Yes, even on RS6K machines its little endian. You should write to PCI mapped register in little endian byte order. Regards, Anil. ** Sent via the linuxppc64-dev mail list. See http://lists.linuxppc.org/