sgb07

• Fixed another save state hang by added IME state to dbg src.
• Fixed PBD hang by pushing off H-Blank another bus clock.
• Added better MBC1M detection.
• Added support for SGB1 frequency.
• Fixed row buffer read/write conflict at SGB1 frequency.
• Fixed partially flashing scanline by giving SNES early notification of a scanline and row buffer completing.
• Removed checks for disabling in-game hooks and associated override cfg option. User responsible for setting enable/disable correctly and running with functioning boot and bios file.

This is the final version unless major bugs are found and there is time to fix them.

sgb06

• Fixed MBC2 register write bug.
• Fixed several games hanging on save state due to serial state machine not going idle.
• Fixed another hang on save state issue with ICD2 idle.
• Fixed joypad data bus bug when both lines asserted.
• Added a few (partially implemented) mappers. See readme.txt.
• Added back brightness patch with MSU on classic.
• Fixed save state audio regression by always allowing dbg src to read/write wave RAM.

sgb05

• Updated reset state of P1 to handle code that relies on uninitialized value.
• Added experimental sprite per scanline increase for pro.
• Added DMA stall on HALT.
• Updated REG logic to separate read and write buffers.
• Added DMA from VRAM support.
• Added config value to allow SGB ingame hooks without needing to enable the existing ingame hooks.
• Added a few more hashes of supported boot and bios files to avoid disabling hooks.
• Changed BOOT register to set on write independent of value.
• Added volume boosting and debug feature to disable SGB enhancements.

sgb04

• Added another envelope register write side effect.
• Fixed APU length (enable) counter bug.
• Added wave RAM protection while channel enabled.
• Updated audio CIC rates and precision. Removed hack to filter one case of noise which is now handled by CIC.
• Changed MSU CIC to reduce accumulator precision. Simplified CIC accumulator logic.
• Fixed duplicate interrupts by removing double trigger on LYC==0 in favor of STAT write spurious int during V-Blank (and other conditions).
• Added single cycle H-Blank status update on LY==0.
• Fixed LY early transition to 0 bug for when it is read during scanline 153.
• Added support for LSDj (128KB SaveRAM). Change from ikari01.

sgb03

• Fixed GB RTC. Known bugs are fixed, but it is not well tested. See readme.txt.
• Updated initial WAV RAM values to match a SGB2.
• Fixed end of frame line match interrupt.
• Added extra line of OAM interrupt.
• Fixed problem with hidden sprites still getting rendered.
• Fixed some cases of partially flashing scanlines by masking OAM LUT reads/writes when DMA is active.
• Fixed interrupt related problems by rewriting STAT interrupt generation logic. Removed hack where OAM interrupt was masked using sprite disable flag.

sgb02

• Fixed stack overflows due to delayed interrupts by masking OAM STAT interrupt when sprites are disabled.
• Updated STAT interrupt code to make match/oam coincident.
• Added MBC1M support. The detection is a hack. It's possible a MBC1 cart is incorrectly detected as MBC1M.
• Fixed popping noises and some other APU bugs by rewriting output and handling unsigned->signed conversion better. Hopefully this is better than before.
• Updated wave sample buffer to only update on timer expiration.
• Updated audio output volume scaling to a closer but still crude approximation of the original SGB2.
• Added square channel register write side effects involving duty position. Sometimes used to creating ringing in output.
• Changed square channel duty cycle relative phase and inversion but may not matter.
• Added some of the APU envelope register write volume corner cases.
• Fixed RETI setting of IME by adding bypass. Exposes bugs in some games.
• Changed PPU pipeline to remove DRN wait.
• Changed interrupts to clean up code a bit.
• Added serial link transfer interrupt.
• Changed MCU bus availability to add more clocks. Speeds up save states a little bit.
• Fixed save state audio glitches by forcing APU writes to disable channels during HLT. There is a tradeoff between forcing all silent channels vs enabling channels with incorrect state.

sgb01

• Fixed window overlay to be per-pixel rather than per-tile. Addresses window graphics problems with CAW bosses and likely many other games.
• Fixed several dynamic range and popping/clicking APU bugs.
• Changed in-game hooks to be fpga-only. Hook is no longer run on SNES NMI or IRQ.
• Added save states (Save=X+R, Load=X+L) for development. To enable, modify sd2snes/config.yml sgb_* settings after booting new firmware. In-game hooks and buttons must be enabled for them to work. One state is recorded in the SRM file. Does not work with MSU audio on SD2SNES classic.
• Changed SD2SNES classic to only load MSU bit file for enabled ROMs to make development easier. The MSU bit file may lag in development.

sgb00

• Initial Release