byuu says:
This release adds ikari's Cx4 notes to bsnes. It fixes the MMX2 intro's
boss fight sequence to be frame perfect to real hardware. It's also very
slightly faster than before.
I've also added an option to toggle the CPU↔coprocessor cycle
synchronization to the emulation settings panel, so you don't have to
recompile to get the more accurate SA1 timings. I'm most likely going to
default this to disabled in bsnes, and *maybe* enabled in higan out of
the box.
StaticRAM (wasn't used) and MappedRAM are gone from the Super Famicom
core. Instead, there's now ReadableMemory, WritableMemory, and
ProtectedMemory (WritableMemory with a toggle for write protection.)
Cartridge::loadMap now takes a template Memory object, which bypasses an
extra virtual function call on memory accesses, but it doesn't really
impact speed much. Whatever.
byuu says:
I added (imperfect) memory conflict timing to the SA1.
Before:
- WRAM↔↔ROM ran 7% too fast
- ROM↔↔ROM ran 100% too fast
- WRAM↔↔IRAM ran 7% too fast
- ROM↔↔IRAM ran 7% too fast
- IRAM↔↔IRAM ran 287% too fast
- BWRAM↔↔BWRAM ran 100% too fast
- HDMA ROM↔↔ROM ran 15% too fast
- HDMA WRAM↔↔ROM ran 15% too fast
- DMA ROM↔↔ROM ran 100% too fast
After:
- ROM↔↔ROM runs 14% too fast
- HDMA WRAM↔↔ROM runs 7% too fast
- DMA ROM↔↔ROM runs 4% too fast
If you enable this with the fast PPU + DSP, your framerate in SA1 games
will drop by 51%. And even if you disable it, you'll still lose 9% speed
in SA1 games, and 2% speed in non-SA1 games, because of changes needed
to make this support possible.
By default, I'm leaving this off. Compile with `-DACCURATE_SA1` (or
uncomment the line in sfc/sfc.hpp) if you want to try it out.
This'll almost certainly cause some SA1 regressions, so I guess we'll
tackle those as they arise.
Tim Allen