BizHawk/BizHawk.Emulation/Consoles/PC Engine/Compat.txt

======= TurboGrafx compatibility issues =======

General: 
 + Don't have a complete list of instructions affected by T flag. Currently warns if SET precedes an unrecognized instruction.
 + Audio volumes are probably wrong.
 + LFO is not implemented, though I can't tell.
 + Screen resolution is an ongoing issue. Some games appear to show garbage beyond what it supposed to be visible.
   Most emulators simply crop the screen at a certain vertical range. For now, I have chosen not to do this.
   Right now the emulator is simply displaying a framebuffer. Eventually, we will do an update that emulates NTSC.
   But for now we're letting this be. There's no intermediate step between emulating a framebuffer and emulating a TV.

Air Zonk          - Fully playable, doesn't freeze, but some gfx/timing issues
Battle Ace        - Some gfx glitches
Cadash            - Minor raster issue. Timing sensitive game.
Chase HQ          - Press start -"O" sprite gets left on screen. probably timing on SATB DMA
Coryoon           - Recent VDC updates broke scrolling. Generally timing sensitive game.
Cross Wiber       - Minor; Raster on wrong line
Davis Cup Tennis  - Some timing issue, splash screen is too slow
Dungeon Explorer  - Freeze in 'intro'
Legend of Hero Ton- Slight gfx- check top of screen
Lode Runner       - Freezes in new game 
Madoo Granzort    - Graphics issues because SGX VPC renderer is not using new frame timing
MML Demo          - Echo channels are too loud (equal volume!)
Outrun            - OK currently but timing sensitive game for future testing
Paranoia          - Game hits BREAK on 3rd level. need to investigate
Power Drift       - Timing glitch... starting new game runs slower than it should
Power Tennis      - Elaborate intro screen doesnt display right
Raiden            - Sprites and BG get out of sync with current timing
Sinistron         - Much less bad raster effect errors now
Tiger Road        - On second level, sprites should be getting masked from the top status area somehow

===================================
Games that need TV Emulation (to varying degrees)
===================================

Final Blaster     - Intro does crazy shit with video modes; not sure what if anything to do about it
Griffon           - Screen goes black because game changes video mode mid-frame

===================================
Games with 'Frame Too Tall' issues:
===================================

Aero Blaster      - Bottom of Screen extends too many lines - like 3 extra or so
Alice             - Screen too tall; glitches when scrolling up, but in pcejin also,  
                    but not ootake; ergo probably a timing artifact
Dead Moon         - Screen is too tall
Jack Nicholas Golf- Some screens are too tall and reveal bad gfx below the intended visible screen
Metal Stoker      - Tearing when scrolling vertically at bottom of screen - screen too tall?
Side Arms         - Screen is like 4 pixels too tall

Stuff I Fixed That's Not In Other Docs:

+ Street Fighter II special mapper
+ Populous has special SaveRAM, 32k starting at page $40.
+ After Burner - There is a 1-instruction delay on changes to IRQ Control Byte taking effect
+ There is a one-instruction delay on changes to the I flag taking effect
  - Affects (Not a complete list): Blodia, Body Conquest 2, Champions Forever Boxing,
    Cross Wiber, Jackie Chan, Jigoku Meguri, New Adventure Island, World Beach volley
  - Actually, I'm not at all convinced there's always a 1-instruction delay on the I-flag.
    But this fixes several games; clearly there are delays in some scenarios. But it's not clear
    to me that this delay is ALWAYS present.
+ Writing to the SATB location register of the VDC requests a VRAM->SAT DMA even if the SAT DMA
  bit is disabled in the DCR.
+ This is in other docs, but Fighting Run requires full MWR register emulation including the various
  4 color modes. It appears to be the only game that requires this, and it's a shitty game. :(