Those mods are all factory made.
They update the MPU to use a single 2716 vs dual 2708s as found in the first few games.
www.PInWiki.com has a discussion about this.
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Chris Hibler - CARGPB #31
Http://chrishiblerpinball.com/contact
http://www.PinWiki.com/ - The new place for pinball repair info