Abstract: An apparatus is provided for controlling the transfer of data between first and second service processors; wherein the respective first and second service processors are adapted to provide respective transfer instructions requesting such data transfers, the apparatus comprising: first lines for conducting digital signals; second lines for conducting digital signals; first integrated circuit for providing digital signals to said first lines in response to first control signals and for receiving digital signals from said second lines in response to second control signals; second integrated circuit for receiving digital signals from said first lines in response to second control signals and for providing digital signals to said second lines in response to first control signals; a first microcode protocol unit for receiving the instructions and for alternatively providing first control signals or second control signals to said first integrated circuit; and a second microcode protocol unit for receiving the instru