Mednafen

Game Boy Advance Documentation

Last updated June 25, 2014
Valid as of 0.9.36.2

Table of Contents:

Introduction

Mednafen's GameBoy Advance emulation is based off of VisualBoy Advance.

BIOS

Built-in high-level BIOS emulation is used by default; however, a real BIOS can be used by setting the gba.bios setting.

Custom Palettes

Custom palettes should contain 32768 8-bit-per-color-component RGB triplets.


Backup Memory Type

To specify the backup memory type on a per-game basis, create a file with the same name as the ROM image but with the extension replaced with "type", in the "sav" directory under the Mednafen base directory.

Example: SexyPlumbers.gba -> SexyPlumbers.type

One or more of the following strings(on separate lines) should appear in this file:

Additionally, the flash size can be specified by specifying the size(real size, or divided by 1024) after the type, like "flash 128" or "flash 131072".



Default Key Assignments

Key(s):Action:Configuration String:
ALT + SHIFT + 1Activate in-game input configuration process for GameBoy Advance pad.input_config1

Key:Action/Button:
Keypad 2B
Keypad 3A
Enter/ReturnStart
TabSelect
Keypad 5Shoulder Left
Keypad 6Shoulder Right
WUp
SDown
ALeft
DRight

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:
gba.biosstring Path to optional GBA BIOS ROM image.
 

Setting:Value Type:Possible Values:Default Value:Description:
gba.enableboolean0
1
1Enable (automatic) usage of this module.
 
gba.forcemonoboolean0
1
0Force monophonic sound output.
 
gba.pixshaderenumnone
autoip
autoipsharper
scale2x
sabr
ipsharper
ipxnoty
ipynotx
ipxnotysharper
ipynotxsharper
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

  • autoip - Auto Interpolation
    Will automatically interpolate on each axis if the corresponding effective scaling factor is not an integer.

  • autoipsharper - Sharper Auto Interpolation
    Same as "autoip", but when interpolation is done, it is done in a manner that will reduce blurriness if possible.

  • scale2x - Scale2x

  • sabr - SABR v3.0
    GPU-intensive.

  • ipsharper - Sharper bilinear interpolation.

  • ipxnoty - Linear interpolation on X axis only.

  • ipynotx - Linear interpolation on Y axis only.

  • ipxnotysharper - Sharper version of "ipxnoty".

  • ipynotxsharper - Sharper version of "ipynotx".
 
gba.scanlinesinteger-100 through 1000Enable scanlines with specified opacity.

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

Negative values are the same as positive values for non-interlaced video, but for interlaced video will cause the scanlines to be overlaid over the previous field's lines(only if the video.deinterlacer setting is set to "weave", the default).

 
gba.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
 
gba.stretchenum0
full
aspect
aspect_int
aspect_mult2
aspect_mult2Stretch 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.

  • aspect_int - Aspect Preserve + Integer Scale
    Full-screen stretch, same as "aspect" except that the equivalent xscalefs and yscalefs are rounded down to the nearest integer.

  • aspect_mult2 - Aspect Preserve + Integer Multiple-of-2 Scale
    Full-screen stretch, same as "aspect_int", but rounds down to the nearest multiple of 2.
 
gba.tblurboolean0
1
0Enable video temporal blur(50/50 previous/current frame by default).
 
gba.tblur.accumboolean0
1
0Accumulate color data rather than discarding it.
 
gba.tblur.accum.amountreal0 through 10050Blur amount in accumulation mode, specified in percentage of accumulation buffer to mix with the current frame.
 
gba.videoipenum0
1
x
y
0Enable (bi)linear interpolation.
  • 0 - Disabled

  • 1 - Bilinear

  • x - Linear (X)
    Interpolation only on the X axis.

  • y - Linear (Y)
    Interpolation only on the Y axis.
 
gba.xresinteger0 through 655360Full-screen horizontal resolution.

A value of "0" will cause the desktop horizontal resolution to be used.

 
gba.xscalereal0.01 through 2563.000000Scaling factor for the X axis in windowed mode.
 
gba.xscalefsreal0.01 through 2561.000000Scaling factor for the X axis in fullscreen mode.

For this settings to have any effect, the ".stretch" setting must be set to "0".

 
gba.yresinteger0 through 655360Full-screen vertical resolution.

A value of "0" will cause the desktop vertical resolution to be used.

 
gba.yscalereal0.01 through 2563.000000Scaling factor for the Y axis in windowed mode.
 
gba.yscalefsreal0.01 through 2561.000000Scaling factor for the Y axis in fullscreen mode.

For this settings to have any effect, the ".stretch" setting must be set to "0".