Known issues
=============

-  Madou Monogatari I (Game Gear)

Has rendering issues due to video timing being different between SMS and GG.
See :
https://github.com/drhelius/Gearsystem/commit/71b7252831e8a50d94a11b491431b52f6c3af8d4

Partially fixed as of f0192681f2daa9d1f225f891119e26dbc4969a54, but
it is still not correct when the sprite moves into the background.

-  93c46 EEPROM Support

Used by a few Game Game games.

Majors Pro Baseball
Nomo's World Series Baseball (J)
Pro Yakyuu GG League (J)
World Series Baseball [A]
World Series Baseball [B]
World Series Baseball 95

Implementations :
https://github.com/OpenEmu/CrabEmu-Core/blob/master/consoles/sms/mapper-93c46.c

World Series Baseball '95 and World Series Baseball will hang up without at least a stub in place.

- LCD Persistence issues

Some games take advantage of the Game Gear's poor LCD screen.
If this behaviour is not replicated then it results in some heavy flickering.

Here's a list of affected games :

-  The Adventures of Batman & Robin (Disappearing HUD)
-  Super Monaco GP 2 (Titlescreen)
-  Space Harrier
-  Ninja Gaiden (affects 3rd & 2nd act)
-  Halley Wars
-  MLBPA Baseball
-  Power Drive (unreleased prototype)
-  James Pond 3 (Overworld level text)

MAME has an implementation of LCD persistence here (first appeared in MESS 0.135) :

https://github.com/mamedev/mame/blob/08cd6110268f9363e6c2cb9f0b6d92c00dadfbd6/src/mame/machine/sms.cpp#L1557

-  Graphics Board

http://www.smspower.org/forums/15032-SegaGraphicBoardV20ReverseEngineering
No support for it given how recent it is. MEKA supports this so i should take a look at it.

-  Space Gun

http://www.smspower.org/Development/SpaceGun-SMS

I need to add back Lightgun emulation.
The code is left turned off for now because most games also support the controllers but this game requires the light gun.

There's also an issue with memory mapping. I believe we don't suffer from that bug ?

-  Sports Pad

Not currently implemented.
In addition to that, a bug has been discovered where the game would sometimes read the input from player 1 for player 2.
Do we really want to implement this bug though ???

https://github.com/mamedev/mame/commit/33c5196a429d0afa801caac3ad24a76bf0ac273d#diff-cafb9b1c2517c95f421c776c3ec74e56