GND 1 [*] * 16 Vdd
R/W 2 * * 15 A3
A2 3 * * 14 A1
A0 4 * * 13 /select
D1 5 * * 12 D2
D3 6 * * 11 D4
D5 7 * * 10 D6
D7 8 * * 9 D0
R/W is high for a read cycle and low for a write cycle. /select is low when the controller is talking to your board. There is a four bit address bus and an eight bit bi-directional data bus. Although there is a Vdd connection provided, it is recommended that you get your +5V from another source (the power port board) unless you plan on drawing very little current. Here is a timing diagram of some sort:
/select ______ _________
|________|
data ----------< VALID >-------
Note that data is valid on the rising edge of /select, so /select can be used as a clock signal in many cases. As always, make sure that you drive the data bus only when /select is low and R/W is high. Hardware that barfs all over the data bus will not be tolerated.
When the controller board resets, CokeOS writes a zero byte to address zero of every I/O port. Your board can use this for initialization.
Here is the pinout of the misc. IO port. Note that this port is backwards from the others on the board -- it's been rotated 180 degrees, and pin 1 is in the opposite corner. Also note that Vdd is in a different place.
GND 1 [*] * 16 TIC3 TIC2 2 * * 15 TIC1 TOC5 3 * * 14 TOC4 TOC3 4 * * 13 TOC2 TOC1 5 * * 12 Vrl Vrh 6 * * 11 An0 An1 7 * * 10 An2 IRQ 8 * * 9 Vdd