Changes

Not sure why bit7 is set in the codes (it should be written like so to the O2 I/O ports, but maybe the bit isn't actually passed to the SP0256 chip)?

Additionally, the expansion module contains 3 built-in speech ROMs with sound effects and various words/phrases like "Amazing", "Come on", "Outch", etc. Moreover, Odyssey 2 game cartridges can contain up to 5 external speech ROMs. For details see "Odyssey 2 Technical Specs" from Daniel Boris.