Mednafen

Sega Genesis/MegaDrive Documentation

Last updated December 31, 2010
Valid as of 0.9.16-WIP

Table of Contents:


Introduction

Mednafen's Sega Genesis/Megadrive emulation is based off of Genesis Plus.


Settings Reference

Caution: Any settings that change emulation behavior as seen from the emulated game are shown with the setting name bolded in the table. One should be conscious of these settings if one has changed them from the default values when using network play or movies, as they can cause desychronizations if not set the same among hosts(or between the recording emulator and the playing emulator).

Setting:Value Type:Possible Values:Default Value:Description:
md.cdbiosstring us_scd1_9210.binPath to the CD BIOS

SegaCD/MegaCD emulation is currently nonfunctional.

 
md.correct_aspectboolean0
1
1Correct the aspect ratio.

 
md.input.port1enumnone
gamepad2
gamepad
gamepad6
megamouse
gamepadInput device for Port 1

  • none - none

  • gamepad2 - 2-Button Gamepad

  • gamepad - 3-Button Gamepad

  • gamepad6 - 6-Button Gamepad

  • megamouse - Sega Mega Mouse
 
md.input.port2enumnone
gamepad2
gamepad
gamepad6
megamouse
gamepadInput device for Port 2

  • none - none

  • gamepad2 - 2-Button Gamepad

  • gamepad - 3-Button Gamepad

  • gamepad6 - 6-Button Gamepad

  • megamouse - Sega Mega Mouse
 
md.regionenumgame
overseas_ntsc
overseas_pal
domestic_ntsc
domestic_pal
gameEmulate the specified region's Genesis/MegaDrive

  • game - Match game's header.
    Emulate the region that the game indicates it expects to run in via data in the header(or in an internal database for a few games that may have bad header data).

  • overseas_ntsc - Overseas(non-Japan), NTSC
    Region used in North America.

  • overseas_pal - Overseas(non-Japan), PAL
    Region used in Europe.

  • domestic_ntsc - Domestic(Japan), NTSC
    Region used in Japan.

  • domestic_pal - Domestic(Japan), PAL
    Probably an invalid region, but available for testing purposes anyway.
 
md.reported_regionenumsame
game
overseas_ntsc
overseas_pal
domestic_ntsc
domestic_pal
sameRegion reported to the game.

  • same - Match the region emulated.

  • game - Match game's header.
    This option, in conjunction with the "md.region" setting, can be used to run all games at NTSC speeds, or all games at PAL speeds.

  • overseas_ntsc - Overseas(non-Japan), NTSC
    Region used in North America.

  • overseas_pal - Overseas(non-Japan), PAL
    Region used in Europe.

  • domestic_ntsc - Domestic(Japan), NTSC
    Region used in Japan.

  • domestic_pal - Domestic(Japan), PAL
    Probably an invalid region, but available for testing purposes anyway.
 

Setting:Value Type:Possible Values:Default Value:Description:
md.debugger.disfontsizeenumsmallDisassembly font size.

     
    md.debugger.memcharencstring shift_jisCharacter encoding for the debugger's memory editor.

     
    md.enableboolean0
    1
    1Enable (automatic) usage of this module.

     
    md.forcemonoboolean0
    1
    0Force monophonic sound output.

     
    md.pixshaderenumnone
    ipxnoty
    ipynotx
    ipsharper
    ipxnotysharper
    ipynotxsharper
    scale2x
    noneEnable specified OpenGL pixel shader.

    Obviously, this will only work with the OpenGL "video.driver" setting, and only on cards and OpenGL implementations that support pixel shaders, otherwise you will get a black screen, or Mednafen may display an error message when starting up. Bilinear interpolation is disabled with pixel shaders, and any interpolation, if present, will be noted in the description of each pixel shader.

    • none - None/Disabled

    • ipxnoty - Linear interpolation on X axis only.

    • ipynotx - Linear interpolation on Y axis only.

    • ipsharper - Sharper bilinear interpolation.

    • ipxnotysharper - Sharper version of "ipxnoty".

    • ipynotxsharper - Sharper version of "ipynotx".

    • scale2x - Scale2x
     
    md.scanlinesinteger0 through 1000Enable scanlines with specified opacity.

    Opacity is specified in %; IE a value of "100" will give entirely black scanlines.

     
    md.specialenumnone
    hq2x
    hq3x
    hq4x
    scale2x
    scale3x
    scale4x
    2xsai
    super2xsai
    supereagle
    nn2x
    nn3x
    nn4x
    nny2x
    nny3x
    nny4x
    noneEnable specified special video scaler.

    The destination rectangle is NOT altered by this setting, so if you have xscale and yscale set to "2", and try to use a 3x scaling filter like hq3x, the image is not going to look that great. The nearest-neighbor scalers are intended for use with bilinear interpolation enabled, at high resolutions(such as 1280x1024; nn2x(or nny2x) + bilinear interpolation + fullscreen stretching at this resolution looks quite nice).

    • none - None/Disabled

    • hq2x - hq2x

    • hq3x - hq3x

    • hq4x - hq4x

    • scale2x - scale2x

    • scale3x - scale3x

    • scale4x - scale4x

    • 2xsai - 2xSaI

    • super2xsai - Super 2xSaI

    • supereagle - Super Eagle

    • nn2x - Nearest-neighbor 2x

    • nn3x - Nearest-neighbor 3x

    • nn4x - Nearest-neighbor 4x

    • nny2x - Nearest-neighbor 2x, y axis only

    • nny3x - Nearest-neighbor 3x, y axis only

    • nny4x - Nearest-neighbor 4x, y axis only
     
    md.stretchenum0
    full
    aspect
    0Stretch to fill screen.

    • 0 - Disabled

    • full - Full
      Full-screen stretch, disregarding aspect ratio.

    • aspect - Aspect Preserve
      Full-screen stretch as far as the aspect ratio(in this sense, the equivalent xscalefs == yscalefs) can be maintained.
     
    md.tblurboolean0
    1
    0Enable video temporal blur(50/50 previous/current frame by default).

     
    md.tblur.accumboolean0
    1
    0Accumulate color data rather than discarding it.

     
    md.tblur.accum.amountreal0 through 10050Blur amount in accumulation mode, specified in percentage of accumulation buffer to mix with the current frame.

     
    md.videoipboolean0
    1
    1Enable bilinear interpolation.

     
    md.xresinteger64 through 655361024Full-screen horizontal resolution.

     
    md.xscalereal0.01 through 2563.000000Scaling factor for the X axis.

     
    md.xscalefsreal0.01 through 2563.200000Scaling factor for the X axis in fullscreen mode.

     
    md.yresinteger64 through 65536768Full-screen vertical resolution.

     
    md.yscalereal0.01 through 2563.000000Scaling factor for the Y axis.

     
    md.yscalefsreal0.01 through 2563.200000Scaling factor for the Y axis in fullscreen mode.