quote from cps2shock...actually the paragraph RIGHT BELOW what you cut and pasted, lol...
"Grey and Orange game boards require the main 'A' board of matching color to work. Green and Blue boards are totally interchangeable meaning Green game boards will work on a Blue 'A' board and visa versa. A Yellow case shows a game is the rent version. These were made to fit 'A' boards as required and were used to entice operators to buy the game. "
Yes, the A board matters. The BLUE US B boards and GREEN japan B boards will not play on an ASIA or SOUTH AMERICA A board. Blue and green B boards physically can not plug into the same A board as a GREY B board and most likely the Orange A board either, but I haven't owned one to know for sure. I do have US, Japan, and Asia B boards and US and Asia A boards though. The BLUE AND GREEN B boards are interchangable ONLY on japan and USA A boards. I have Asia and USA because well,
Grey B boards are cheaper