War of the Gems   - waiting for SPC

History
"""""""
 0.40
  65c816: Fixed a bug that could cause WAI to miss a waiting IRQ
  Source: Many changes to reduce repetition in 65c816/SPC opcodes
  65c816: Made a few improvements to the register allocation
  Sound: Fixed a possible buffer underrun bug
  PPU: Went back to the old VRAM read method - 'VRAM read buffering'
   might make more sense, but it doesn't work well with ActRaiser...
  PPU: Fixed a bug in VRAM full address increment (untested...)
  Render: Completely changed the tile caching method
  DMA: Made a few slight changes to the DMA/HDMA emulation
  Timing: Rewrote event handling, now using more correct timing for
   rendering and HDMA
  Timing: Implemented pre-NMI delay (fixes Chrono Trigger intro freeze)
  Timing: Fixed controller ready bit in HVBJOY (fixes Chrono Trigger
   combat slowdown and combat menu flickering)
    Thanks to Neill Corlett for info!
  Timing: Implemented much more correct H-IRQ timing, should also allow
   multiple H-IRQ's on a scanline
  Source: Ported some of the source from GNU-AS (GAS) to NASM
   (memory mapper, APU skipper, special screenmode setup)
  Joypad: No longer reporting parodoxical inputs - up and down can
   no longer be pressed at the same time, nor can left and right
   (fixes a potential problem in Zelda 3 name entry)
  SPC700: Now updating SPC timers at least once every Vblank
  SPC700: Fixed a major bug that caused the SPC to freeze after about
   17.5 minutes of virtual execution