And just for reference: Actronics Challenge Racer (VFD game)- HD38750-A58 There's two Twinvader games listed here: http://www.handheldmuseum.com/Actronics/Twinvader.htm And they are also sold as Twinvader III (and say that on the back usually), but the large and small versions seem to have different chips. Twinvader (large white one)- HD38800-A51 Twinvader (smaller brown one)- HD38750-A56
