gb: disable for now, buggy
helios: default to stereo sound
md: add svp support (using notaz implementation)
md: fix bug on vdp long reads
md: fix emulation stall on invalid vdp write
md: fix joypad detection 6btn
md: fix window plane
md: fix Z80 SP default value
md: avoid fm audio clipping
md: add satCache
md: add support for soft reset
md: only stop 68k on DMA MEM_TO_VRAM
md: savestate support for ssf2/sega mapper registers
md: support flat ROM mappers > 4MB
md: initial 128kb VRAM vdp support
md: support roms that require both ssf2 mapper and sram
sms: vdp handle tilemap mirroring
z80: use z80disasm from mame