The podule connector that is on the port controller conforms to the standard podule specification ``Acorn A Series Podules'' with two exceptions to standard use. In Acorn machines writes are done to the high 16 bits and reads from the low 16 bits. On the port controller both reads and writes are done using the low 16 bits. The second change is in the select line that is provided to the podule backplane. Podule backplanes normally use A21 to enable the selection of the Memc Podule Strobe signals; the Simple Podule select enable being generated by IOC. On any machine with an IO controller other than IOC on the motherboard (ie. the xilinx chip on the port controller), the select signal supplied to the backplane in place of A21 must exclude the range of IO addresses used by the motherboard. This is performed in the port controller PAL.