Remember, if you get an Amiga 500 and decide you want to use an ACA500 later, it only works with Rev 6A and higher boards.
Actually, the ACA500 works in a revision 5 PAL A500. Therefore, it should be possible to use in a rev 5 NTSC if you switch it to PAL and change Agnus to a 8371 or 8372A and disconnecting pin 41.
