cartridge reading!
have some cleanup to do:
clean up sega dumping so don't need a page0/1
implement sega single reads
Add GBA to some of the common opcodes
dumping Don't think need addrH |= of mapper, but maybe this is key to
cleaning up first note..
gba, sega, n64 has extra NOPs, remove and test.
create pinport renames for sega pins, move mask defines to pinport.h
clean up comments for genesis page reads..
c1b35baf06