Mednafen

Sega Master System Documentation

Last updated March 19, 2024
Valid as of 1.32.1

Table of Contents:

Introduction

Mednafen's Sega Master System emulation is based off of SMS Plus.

Sega Master System emulation in Mednafen is a low-priority system in terms of proactive maintenance and bugfixes.

Custom Palettes

Global Filename:Description:
sms.palSMS 6-bit BGR

64 RGB triplets

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:
sms.fmboolean0
1		1Enable FM sound emulation when playing domestic/Japan-region games.
 
sms.slendinteger0 through 239239Last displayed scanline in NTSC mode.
 
sms.slendpinteger0 through 239239Last displayed scanline in PAL mode.
 
sms.slstartinteger0 through 2390First displayed scanline in NTSC mode.
 
sms.slstartpinteger0 through 2390First displayed scanline in PAL mode.
 
sms.territoryenumdomestic
export		exportSystem territory/region.
  • domestic - Domestic(Japanese)

  • export - Export(World)
 

Setting:Value Type:Possible Values:Default Value:Description:
sms.enableboolean0
1		1Enable (automatic) usage of this module.
 
sms.forcemonoboolean0
1		0Force monophonic sound output.
 
sms.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(if the "video.deinterlacer" setting is set to "weave", the default) field's lines.

 
sms.shaderenumnone
autoip
autoipsharper
scale2x
sabr
ipsharper
ipxnoty
ipynotx
ipxnotysharper
ipynotxsharper
goat		noneEnable specified OpenGL shader.

Obviously, this will only work with the OpenGL "video.driver" setting, and only on cards and OpenGL implementations that support shaders, otherwise you will get a black screen, or Mednafen may display an error message when starting up. When a shader is enabled, the "sms.videoip" setting is ignored.

  • 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".

  • goat - Simple approximation of a color TV CRT look.
    Intended for fullscreen modes with a vertical resolution of around 1000 to 1500 pixels. Doesn't simulate halation and electron beam energy distribution nuances.
 
sms.shader.goat.fprogboolean0
1		0Force interlaced video to be treated as progressive.

When disabled, the default, the "video.deinterlacer" setting is effectively ignored with respect to what appears on the screen, unless it's set to "blend" or "blend_rg". When enabled, it may be prudent to disable the scanlines effect controlled by the "sms.shader.goat.slen" setting, or else the scanline effect may look objectionable.

 
sms.shader.goat.hdivreal-2.00 through 2.000.50Constant RGB horizontal divergence.
 
sms.shader.goat.patenumgoatron
borg
slenderman		goatronMask pattern.
  • goatron - Goatron
    Brightest.

  • borg - Borg
    Darkest.

  • slenderman - Slenderman
    Spookiest?
 
sms.shader.goat.slenboolean0
1		1Enable scanlines effect.
 
sms.shader.goat.tpreal0.00 through 1.000.50Transparency of otherwise-opaque mask areas.
 
sms.shader.goat.vdivreal-2.00 through 2.000.50Constant RGB vertical divergence.
 
sms.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, for a sharper image, though the "autoipsharper" shader may provide better results.

  • 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
 
sms.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.
 
sms.tblurboolean0
1		0Enable video temporal blur(50/50 previous/current frame by default).
 
sms.tblur.accumboolean0
1		0Accumulate color data rather than discarding it.
 
sms.tblur.accum.amountreal0 through 10050Blur amount in accumulation mode, specified in percentage of accumulation buffer to mix with the current frame.
 
sms.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.
 
sms.xresinteger0 through 655360Full-screen horizontal resolution.

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

 
sms.xscalereal0.01 through 2564.000000Scaling factor for the X axis in windowed mode.
 
sms.xscalefsreal0.01 through 2561.000000Scaling factor for the X axis in fullscreen mode.

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

 
sms.yresinteger0 through 655360Full-screen vertical resolution.

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

 
sms.yscalereal0.01 through 2564.000000Scaling factor for the Y axis in windowed mode.
 
sms.yscalefsreal0.01 through 2561.000000Scaling factor for the Y axis in fullscreen mode.

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