From Emulation General Wiki
Jump to navigation Jump to search
Current version: 1.25.0-UNSTABLE
Active: Yes
OS: Multi-platform
Authors: Ryphecha, Mednafen Team
Official website:
Source code: SourceForge

Mednafen is a multi-system emulator, driven from the command-line. Many of its cores are ports of other emulators, but many of them are also original. Its PlayStation and PC Engine (TurboGrafx-16) original cores are notable for their high quality, compatibility and accuracy.

Mednafen is an acronym for "My Emulator Doesn't Need A Frickin' Excellent Name".


Supported systems

System Based on code from:
Atari Lynx Handy
Game Boy Advance VisualBoyAdvance
Neo-Geo Pocket/Color NeoPop
Famicom (NES) FCE Ultra
Super Famicom (SNES) bsnes
Nintendo Virtual Boy Original. NEC V810 CPU core based on Reality Boy.
PC Engine (TurboGrafx-16) Original. CD-ROM interface based on PC2E.
PC-FX Original. NEC V810 CPU core based on Reality Boy.
PlayStation Original.
WonderSwan/Color Cygne
Mega Drive (Sega Genesis) Genesis Plus
Sega Master System and Game Gear SMS Plus


Mednafen only has a command line interface, so its interface might be hard to use to new users.

The best cores in Mednafen are those that are original - which are the PS1, PCE, PC-FX and Virtual Boy cores. The PCE core is one of the best emulators for that system, with a Fast and Accurate version. The PS1 core is native resolution only, and features high degree of accuracy and compatibility.[1] The Virtual Boy core is one of the best for the system.

Other cores improve upon emulators that have been long abandoned and rarely updated. These include the Neo-Geo Pocket, WonderSwan Color and Atari Lynx cores.

Other cores are less useful, as there are better options in stand-alone emulators (NES, Genesis, Master System and SNES). These cores might even be based on out-dated versions. For instance, the SNES core is based on an old outdated version of bSNES. This is before the performance/accuracy/balanced cores - 0.50x territory - with a couple of changes by Ryphecha.

It is unknown at this time whether Mednafen's GBA core is better than VBA-M.

RetroArch uses the PS1, PCE, Neo-Geo Pocket, Virtual Boy, and WonderSwan cores of Mednafen, so it might make sense to use that instead.

Using Mednafen

Mednafen is pretty easy to get up and running. You can use a frontend like medgui. However, a good text editor like Notepad++ is all you need if you need to change settings.


Most cores do not require any BIOS except for the PS1, PCE-CD and PC-FX cores. BIOS files need to be placed into a folder called "firmware" in your Mednafen directory. Mednafen is very picky about which BIOS to use. The ones that you might need are:


  • SCPH5500.bin - (NTSC-J) Required for Japan-region games.
  • SCPH5501.bin - (NTSC-U) Required for North America/US-region games.
  • SCPH5502.bin - (PAL) Required for Europe-region games.


  • syscard3.pce


  • pcfx.rom

All of these come with the RetroArch BIOS pack, and are correctly named.


For most systems, Mednafen only needs the rom file; but to load PS1 games, Mednafen requires CUE sheets to know where the music data is. Ensure that the CUE sheet is properly set up in order for the game to run. See the Cue sheet (.cue) page for more info.

Loading a game

To load a game in Mednafen, simply drag and drop your rom or CUE file onto mednafen.exe, or if you prefer, you can use the command line. Mednafen requires no special commands, such as the desired system. For example, in Windows, the command would look like C:/Emulators/Mednafen/mednafen.exe C:/Roms/Nintendo/battletoads.nes

Dual Analog Controllers with PS1

To enable analog sticks and rumble on DualShock controllers, open the mednafen-09x.cfg file, search for "psx.input.port1" and change gamepad to DualShock. Do this for port2 if you wish to play multiplayer games with the features of DualShock controllers.

Configuring Controls

Once in-game, to configure your controller at any time, press Alt+Shift+1 and it will guide you through the setup. Press Alt+Shift+2 and so on for each additional controller for multiplayer.

Graphical Enhancements

Sprite Limit

This is a feature on older systems, due to hardware limitations, that makes it only display so many sprites could be on screen at the same time. Most systems got around this limitation by alternating which sprites were on screen each refresh, causing the sprite to flicker. Mednafen's default settings are true to the original system limits,  but this can be disabled in the cfg file. Here is the list of options from the cfg file to change from 0 to 1 if you don't wish to have the limit.

  • nes.no8lim
  • pce.nospritelimit
  • pce_fast.nospritelimit
  • pcfx.nospritelimit


Mednafen supports the usual cheats such as GameShark, Code Breaker, and Action Replay. The cheats menu can be accessed (or quit back to normal gameplay) with ALT+C.

The cheat engine interface is command-based but still easy to use. Each time a menu appears, you have a bunch of options with a number (or key) before each choice. You're supposed to write the number (# just means to choose the number for the line you want) or letter standing for your choice. Occasionally, when asked to input some values or names, a value appears between brackets after the question - if that's what you want to write down, you can simply leave the entry field empty and press Enter.

To add an existing GS/AR/PAR/CB cheat code, use "Gameshark Codes". Else, if you have a memory address and a given value for it, choose "Search Code" then "Add Code", then put in the address (as $XXXXXXXX), the byte range depending on the values your variable can take (1 is 0-255, 2 is 0-65535, etc), and the numeric value proper (in decimal, or hexadecimal if followed by a lower-case h). Various cheat types exist too (S(substitute on read), C(substitute on read with compare) or R(replace value before vblank) -- R being the default recommended option).

Searching for new cheat codes is also possible. The general idea being comparing variables, going back to gameplay so that this variable changes then back to the cheat engine searching for any variables that changed in that particular way. For example:

  • Infinite Health / Ammo / Time / Money: you start with 5 hearts, reset search (in the cheat engine, not reset the game you silly!), you get hurt to 4 hearts, search variables that decreased, get healed back to 5 hearts, search variables that increased, and so on. For money you can start with 0 when you have 0 gold and try earning/spending money. You could try using save states as well when you don't have as much freedom changing the value.
  • Infinite Lives: It's game over when the internal variable for "Lives" is 0. So in some cases, when it shows "REST/LEFT=1" in-game and you lose a life then it becomes 0 but you're still allowed to play on your last life, that means the internal counter for lives has actually changed from 2 to 1 and not from 1 to 0, but in other games (where if you die on "LIVESx1" it's game over) it's not the case. In the case of lives, you actually know the exact value: reset search initially, then (if you have 2 lives on a game that allows you to play on "LEFT=0") search for variables with values equal to 3. Lose a life, search for variables equal 2, and so on.
  • Character Modifier / Level Modifier / Having an Item: reset search, play without changing whatever you're searching for (let's say the stage), do lots of searches for new value equals old value. In-game, change it, then do a new value doesn't equal old value. And so on.
  • Walk Though Walls / Invincibility / In-game Cheats & Features : you need to find the value that tells the character if he can move or not (he can't really move when walking against a wall) / if he's blinking or being invincible right now after getting hurt. Same methods as before, but there are hints that could be useful here -- both states could be 0/1, or something else... for example, one could assume 0 is not enabled and 1 is enabled.
  • Debug Modes: stuff that stays 0 no matter what, extra off-screen inaccessible options in menus, extra dialogue... you name it. Have fun experimenting.

The goal of these searches is to narrow down the list of results to a single or handful of addresses (variables) pertinent directly to whatever we're searching for. The search always starts with "Reset Search", going back in-game (Alt+C) to play and change stuff, then back to the cheat engine to compare the "Original" value with the "Current" value. Then you check the results page which must get smaller and smaller (if it's 0 results, you screwed up and need to reset search to try again). The comparing options offered by Mednafen are as follow, with O being the Original value, and C being the Current value (when you reset a search, they're the same):

  • 1) O==V1 && C==V2 : if you know the explicit numerical values for the variable you write it here. First time, just write same value in both. Subsequent times, leave O blank and press Enter so that you don't write the old value again, and write the current value under C.
  • 2) O==V1 && |O-C|==V2 : same, but instead of writing the current value you write by how much it changed (0 if old value equals new value)
  • 3) |O-C|==V2 : you write by how much it changed (0 if old value equals new value)
  • 4) O!=C : if old value doesn't equal new value
  • 5) Value decreased : if new value smaller than old value
  • 6) Value increased : if new value bigger than old value

Further Reading

Memory cards

Shared memcards

Use this so that there is a shared memory cards for all games:

Create psx.cfg, and add the line: filesys.fname_sav %s.%X
Here's the full documentation:

Emulation bugs, crashes and save states can corrupt your memory card data.


To transfer memory cards, follow this guide. Also, in games with multiple discs with saves that carry over, you have to follow the same procedure.

Mednafen creates memory card files for each individual game, in contrast to PCSX-R/ePSXe where all game saves are stored into 2 memory card files. To transfer memory card files from PCSX-R/ePSXe to RetroArch:

  • Start game in RetroArch.
  • Go to system folder. Copy the names of the .mcr files created for the game.
  • Delete them.
  • Rename the files you want to transfer with the names of the RetroArch memcard files.
  • Place the new ones in the system folder.



Cores that work with NetPlay:

  • PC Engine (TurboGrafx-16)/PC-CD/SuperGrafx (option for both accuracy and fast cores)
  • PC-FX
  • NES
  • Genesis
  • Master System
  • SNES
  • PlayStation
  • You can make and load savestates
  • Netcode allows for people to join a game that's already in session
  • In-game chat
  • Playing it fullscreen works (sometimes)
  • Command-line only (you can use a frontend, though)
  • Weird, convoluted settings (or lack thereof)
  • SNES emulation will be slow to you if you're on a low-end computer (uses bsnes core)
  • PlayStation is inexplicably slow (haven't checked to see what core it uses, but probably has one that's focused on accuracy)
  • Only supports 2 Players on Genesis.
  • Frontend doesn't always save settings correctly.
  • Frontend defaults to detecting compressed ROM archives instead of the actual ROMs (you can still load uncompressed ROMs by selecting "All files *.*" from the dropdown menu).
How to

It's recommended that you download a frontend

  1. Run MedGui.exe
  2. You'll get a small window. On your left, you'll see two arrow buttons with a console/handheld icon in between. Choose your desired platform.
  3. Click the button with the blue lightning icon and look for the folder that contains your game(s). The emulator looks for compressed archives by default, but you can still load uncompressed files by clicking on the drop down menu.
  4. Pick your game.
  5. Click the button with a checkered red ball and joystick to start the game.
  6. You'll then (very likely) get a message an update prompt. Click Yes, and wait.
  7. Start the game. If it asks you to update again, ignore it and restart the emulator.
  8. While the game is loaded, press ALT + SHIFT + 1 to map your controller. You'll get several options per button (for example, UP 1, UP 2, UP 3, etc.). Just map the first one to your controller, and the rest to a key you'll never press. You will have to repeat this step for every emulator core.
  9. Close the emulator.
  10. Click the arrow button on the right side of the window. It should expand it.
  11. Click Advanced Mode.
  12. Click the tab called Media/Network/Utility.

For Hosting:

  1. In the Netplay-Server section, you have the following options:
    • "Max Clients", as in, the number of people that can connect to your server (not necessarily players; theoretically you can use this as a makeshift stream)
    • "Conn. Timeout" which is the number of seconds you'll allow for your clients to attempt establishing a connection
    • "Port" where you'll choose one an open TCP/UDP one
    • "Password" which you can establish or leave blank
  2. When you're done fiddling with your settings, click Create standard.conf
  3. Click Create Server. A cmd window will appear.
  4. Click My IP to obtain your external IP address, and share it along with your port to your friend(s).
  5. Launch the game.
  6. Press T, and type /server localhost.
  7. Wait for other people to connect.

If you're Connecting:

  1. In the Netplay-Client section, you have the following options:
    • "Host", which is the server's IP you'll connect to
    • "Port, which is the one used by the server (which you should also have open on your end).
    • "Password", blank if there is none.
    • "Nickname" where you type whatever you want.
    • "Localplayer" is the number of players that will also be playing from one computer.
    • "Small font" which makes the chat font smaller.
  2. When you're done fiddling with your settings, launch the game.
  3. Press T, and type /server IP_goes_here.

You can chat in-game by pressing T. Also, remember that you can drop in and out of the game at any time, so you don't need to reset the game if someone accidentally disconnects. There are way too many settings, commands and features to list, so take a look at the emulator's documentation.

External links

Mednafen Tutorial