The main card has the following :
P1 2 pin RS232 select jumber for debug (ARM or FPGA)
P2 2 pin 5V external power input
P3 32 pin IO cable expansion 1
P4 9 pinD RS232
P5 Molex 12V/5V external power input
P6 2.1mm 5V power input for wall adapter
P7 32 pin IO cable expansion 2
P8 main SAMTEC board stacking connector. Lots of IO
P9 3 pin ARM debug serial connector
P10 2 pin ARM ERASE
P11 2 pin ARM TST
P12 micro USB (for updating ARM firmware)
P13 6 pin FPGA JTAG debug
P14 5 pin USB header (parallel with P12)
P15 sub SAMTEC board stacking connector. Video+Audio+Joysticks
P16 SD card
P17 2 pin external ARM reset input
P18 2 x 9pinD enhanced joystick inputs
P19 2 pin soft reset input (parallel with S2 push button)
P20 SVHS / composite video output
P21 2 x 6pin PS2 inputs (mouse / keyboard)
P22 DVI output (HDMI + analogue video for SCART/VGA)
P23 3.5mm stereo audio output
There is also a patch area to the left of P3 which has some test points for wiring up extra IO.
I have a floppy connector on one of my expansion patch boards - you can see pictures of this board on the FPGAArcade website if you scroll down a bit.
I might add one to the release expansion board, it's easy to do and might be useful.
/Mike