I believe one of the problems was the earlier revisions of the sound/speechboard had a hardware bug and were unable to address 2 2732 Eproms. I did use the 2764 speech rom from the Davroux brothers. It wasn't very difficult to adapt the board to use the single 2764 Eprom configuration. Although you need to have some solder skills of course. The changes can be easily reverted if necessary. The speech rom really adds something to Haunted House. It's a great job from Thierry and François.