Welcome to GenesisPlus - MorphOS v2.1b
Genesis-Plus emulates the classic Sega Genesis/Megadrive,
Sega/MegaCD,MasterSystem and GameGear game consoles.
SegaCD support requires a bios file called BIOS_CD_U.bin
in the bios/ directory. SegaCD games must be in bin/cue format.
Select the .cue file to launch the game. If it becomes unstable
you probably have a bad cue file.
Press TAB key to open save state manager. Save states are
available for Genesis, MasterSystem, GameGear and SegaCD.
- Documentation -
- User Interface Options -
- GUI Interface -
load - select a genesis/megadrive game image to play
start - start the emulation
overlay - enable overlay support for scaled and smoothed image
window - enable playing inside a resizable window (requires overlay)
scanline - enable playing with simulated tv scanline effect
vsync - Synchronize the video frame to avoid screen tearing
this may be too slow on some systems so try both options
systemcycle - This cycle gadget lets you cycle through your game library
for each supported console type
listview - You can quickly select roms in your roms/ directory from here
- Configure Sound -
This is a window with various sound configuration options.
You can set the Master Volume for all sound channels.
FM Sound module Toggle:
You can enable or disable an enhanced ym2413 FM Sound output
module that is compatible with many Sega Master System games
giving enhanced sound output. This setting will only take effect
after restarting the emulation. If the FM mode is changed
once a game is started then the game will be automatically
reset to enable the changed FM Sound mode.
This will enable a sound filter mode
You can toggle between the original 9bit DAC of the Sega Genesis
or use a 14bit enhanced mode. The main difference is you will hear
less background hiss with 14bit mode enabled but it may change the
sound of the original music slightly.
Change how many Audio Buffers are allocated for playing back audio.
More buffers introduces latency so sound will not sync up with the
picture as closely. Keep this as low as possible with good results.
On slower systems increasing the buffers may improve playback.
Adjust frame timing to sync better with your display refresh rate
and reduce sound from crackling or popping on some systems. Default
value of 16 is for a 60hz monitor. On Higher refresh rate LCD panels
it might be useful to lower this value a bit. Lowering too far may
result in stuttering movements in game. NTSC and PAL are adjusted
separately to match the game region. 19 is the default for normal
PAL timing and 16 for NTSC timing.
- Configure Input -
This allows you to configure where each button is mapped
on your gamepad. (lowlevel.library/Poseidon/Sensors) Set
your controller to either port1 for the first player or
port2 for 2nd player in the Poseidon prefs menu.
Select which player you are configuring controls for using the
cycle gadget. Then click once on which control you want to map
for either USB GamePad, XBox 360 gamepad or Keyboard. You will
then have to press a key/button to map it to the control. Do
this once for each control.
psg volume - adjust the in game sound volume
border - enable or remove borders from GameGear and SMS display
Scanline X2 - double sized scanline mode for window play. This
is only possible if the double sized output will fit on your
default public screen. You may need a screen resolution larger
than 1024x768 to double SMS or Genesis games.
compact - make gui more compact
bg - remove background graphics for a more standard gui look
Save States and sram:
You can save a temporary snapshot or "state" of the
current running game by pressing keys 1 - 4 to save
position and keys 6 - 9 to reload the position.
(on keyboard not numpad) sram is automatically saved
and loaded by the emulator as needed. All save data
is stored in the "sav/" drawer.
Save State Manager:
Press TAB during gameplay for a gui save state manager.
You can save and load up to 4 positions by selecting the
Save Preview - Save a preview image for the current game.
- CLI Interface -
Template: genesisplus-mos <romname> <options>
Example : genesisplus-mos roms/sonic.bin -winplay
-winplay : play inside window using overlay
-overlay : play fullscreen using overlay
-scanline: play using simulated tv scanline effect
Passing no <options> : fullscreen without overlay support.
If no <romname> or <options> are passed, the MUI gui
will be launched instead.
- Keyboard and Gamepad controls -
GenesisPlus can be controlled with a keyboard or gamepad.
Gamepads are supported either through Poseidon v2.2,
lowlevel.library or Sensors.library depending on connection
type. Genesis game images can be copied to the "roms/"
directory for quick access. There are seperate drawers for
each supported console type and a seperate path can be used
XBox360 controller support note:
Controller must be plugged in before starting the emulator
and must not be unplugged until the emulator is closed again.
Please ensure you copy all contents of the archive
if updating from an earlier release!
Default Keyboard Controls:
button A - z
button B - x
button C - c
pause/start - enter
dpad - arrow keys
1 to 4 : save states 1 through 4
6 to 9 : restore previously saved states
- Version History -
v2.1b May 20 2020
- Fixed shortened save filenames for GameGear games
- sram only gets saved for games that actually have a valid sram
v2.1 April 29 2020
- Added double size scanline mode for all consoles if pubscreen size allows
- Added border removal option for GameGear and SMS games
- Fixed black pixel borders around all window modes
- Fixed error in input config causing down direction to be always pressed
v2.0b March 18, 2020
- Small bugfix to the overlay modulo value to fix corrupted gfx
v2.0 March 11, 2020
- Added a sound config window with new options available
- FM Sound toggle added for SMS games
- Filter option added for SMS and Genesis
- Original and Enhanced ym2612 sound modes are enabled
- Fixed a bug that was causing the sound to crackle occasionaly
- Updated all source code to latest GenesisPlus-GX core
v1.9 April 25 2018
- Reworked video mode system from hu-go! v1.5 implemented here
- Fullscreen overlay mode aspect ratio correction
- Windowed and fullscreen scanline modes aspect ratio corrected
- Fixed SegaCD mode to be working again - was broken in v1.8a
- .gen added as a valid filename extension
- Fixed videomode not changing sometimes causing a lockup of system
- Most lockup situations fixed
v1.8a April 22 2018
- Executable is slightly smaller by eliminating some uneeded things
v1.8 April 18 2018
- Updated to latest GenesisPlus GX Core 1.7.5
- Some stability fixes
- Runs on latest version of my supporting functions
- Savestate window opens in same position as the emulation window
- Savestate file format changed - old states need to be removed
- Savestates now support SegaCD games
- Quicker open/close of savestate window using mui notifications
- Various small tweaks and fixes
v1.7 July 13 2014
- filters employed to only show valid rom filenames (.cue|.bin|.smd||.sms|.gg)
- auto detect of pal and ntsc roms and set audio/video timings accordingly
- preview pics in startup window added
- thumbnails added to savestate manager
v1.6 September 13 2013
- fixed C button USB gamepad mapping
- fixed some unfreed signals on exit
- fixed certain roms locking up the system issue
v1.5 September 03 2013
- Major update complete overhaul of emulation core to
new based on the latest GenesisPlus Wii version
- Sega CD, MasterSystem and GameGear emulation
- Better window size handling
- Seperate rom dirs for each supported console
- New input configuration panel
- XBox 360 gamepad support via sensors.library
- New save state manager panel
- Many other bug fixes and improvements
v1.4b June 28 2013
- Rewrote display init stuff to work better on G5 and laptops
- Screen borders are properly blanked on all settings
- Display is properly centered in scanline+overlay+fullscreen
v1.4 Jul 5 2008
- FullScreen + Overlay mode clones the Ambient resolution
- Fixed MUI colors to work with most configs
- Added video sync option (fix screen tear on some systems)
- Added compact gui mode
- Option to remove background patterns
- Improvements to the spacing and resizing of gui elements
- audio channels are allocated only while emulation is running
v1.3 May 10 2008
- Switched to the latest GameCube/Wii
version of the Genesis-Plus source code
which features better sound, improved cpu
cores and sram emulation. etc.
- Enabled full stereo sound output
- sram auto load/save added
- Save states made operational
- Iconifies with program icon now
- Added reset key on F12
- Commodity info text shortened
- Added 1 and 2 player joypad configs
- Added selectable rom path
- Stability fixes
v1.2 October 15 2007
- GUI is now resizable
v1.1 July 22 2007
- Fixed sound support so most games have full audio now
- Updated audio engine for better audio/video sync
- Added scanline graphics mode
- Added quick rom selector
v1.0 April 28 2004
- Initial Release!
GenesisPlus-MorphOS port by Kelly Samel
Original emulation code by Charles Mac Donald (http://cgfm2.emuviews.com/)
Z80, 68000 and YM2612 cores by the MAME project (http://mamedev.org/)
Alternate YM2612 core by Stéphane Dallongeville (http://gens.consolemul.com/)
SN76489 core by Maxim (http://www.smspower.org/maxim/)
SVP Core by Notaz (http://notaz.gp2x.de/svp.php)
Original Gamecube's port by Softdev, Honkeykong & Markcube
Enhanced GC/Wii port by Bloze and EkeEke (genplus-gx.bountysource.com/)
genesisplus-morphos site : http://realstar.neocities.org
genplus gx site: : http://code.google.com/p/genplus-gx/
original genesis plus site : http://cgfm2.emuviews.com/