Game Boy, Game Boy Color, and Game Boy Advanced Emulator

Last update: Jan 4, 2023

Overview

SkyEmu

SkyEmu is low level cycle accurate GameBoy, GameBoy Color and Game Boy Advance emulator that I have been developing in my spare time. Its primary focus is to provide a good user experience through a good mixture of tradeoffs of accuracy, performance, features and usability. It is still fairly early in development and should be considered as beta quality.

Web App Based Build (Desktop/iOS/Android)

The latest version of the emulator can be played at the following address as a progressive web app:

https://skylersaleh.github.io/SkyEmu/

On Mobile platforms it is recommended to add to the home screen and launch from there. This will prevent the web browser from auto deleting save files and will remove the browsers UI.

Drag and drop a rom in to load it or click on the Load .GB/.GBC/.GBA button to open a menu to select a rom.

Note: A GBA BIOS is not required as SkyEmu bundles an open source replacement BIOS.

Controls:

WASD: D-Pad
J: A button
K: B button
': Select button
Enter: Start button
U: L shoulder
I: R shoulder

On mobile platforms an onscreen touch screen controller is provided.

Native Build Instructions

Native builds are experimental currently but can be built using the following commands:

mkdir build
cd build
cmake .. 
cmake --build .

The output binaries should be in the build/bin folder

Native builds should work for the following platforms although they are currently not well tested:

Windows
Mac OS X
Linux
iOS
Android

Accuracy/Compatibility

SkyEmu has been tested on 100s of ROMs and most common games should be playable with no to minor bugs currently. However, the GBA emulation is significantly more accurate than the GB/GBC emulation.

GBA:

Per Pixel PPU Implementation capable of both scan line and mid scan line effects (SkyEmu is the only GBA emulator released to support this)
Passes the AGS Aging Test ROM (SkyEmu is the second SW based GBA emulator to ever pass this)
Can run difficult to emulate GBA games such as the NES Classics Series, Golden Sun and Hello Kitty Miracle Fashion Maker
100% Passes all ArmWrestler Tests
100% Passes all FuzzARM tests
100% Passes arm.gba and thumb.gba
Passes 1860/1920 GBA Suite timing tests when utilizing the original Nintendo GBA BIOS (the bundled BIOS is less accurate)
Full instruction pipeline and prefetch emulation

GB:

Passes all of Blargg's CPU instruction tests
Passes DMG and GBC acid2 PPU conformance tests
Passes MBCtest
Scan line based PPU implementation
Anti-aliased audio synthesis with support for APU changes per sample (supports Pikachu's voice in Pokemon Yellow/Pokemon Pinball)

Comments

SkyEmu v2
This pull request is a parent for tracking the changes for SkyEmu 1.5.

The latest builds of dev are available at the below links:

Web Build: https://web.skyemu.app/branch/dev/

Windows: https://nightly.link/skylersaleh/SkyEmu/workflows/deploy_win/dev/WindowsRelease.zip

macOS: https://nightly.link/skylersaleh/SkyEmu/workflows/deploy_mac/dev/MacOSRelease.zip

Linux: https://nightly.link/skylersaleh/SkyEmu/workflows/deploy_linux/dev/LinuxRelease.zip

Current Status: BETA Testing

SkyEmu v2 Goals, Release Gates and Progress:

>3 Major Features:

[x] Persistent Save States (https://github.com/skylersaleh/SkyEmu/pull/81)

[x] Loading ROMs from zip files

[x] Shaders (https://github.com/skylersaleh/SkyEmu/issues/41)

[x] Loading of GB/GBC Boot ROMs

[x] Boot GB games from GBC Boot ROM and get GBC colors

[x] GB RTC emulation

[x] https://github.com/skylersaleh/SkyEmu/issues/112

[x] https://github.com/skylersaleh/SkyEmu/issues/113

Fix > 10 games:

[x] (GBA) Final Fantasy Tactics: Fixed in game save

[x] (GBA) Top Gun Combat Zones: Fixed bug that prevented being able to start the game

[x] (GB) Alleyway World (GB): Fixed a bug that prevented the users input from being able to move the paddle

[x] (GB) Pokemon Red: Fixed corruption on game loading screen

[x] (GBA) 007 Everything or Nothing: Fixed audio screeching

[x] (GBA) Beyblade V-force - Ultimate Blader: Fixed audio clicks/pops https://github.com/skylersaleh/SkyEmu/issues/61

[x] (GBA) https://github.com/skylersaleh/SkyEmu/issues/45

[x] (GBA) https://github.com/skylersaleh/SkyEmu/issues/55

[x] (GBA) https://github.com/skylersaleh/SkyEmu/issues/63

[x] (GBA) https://github.com/skylersaleh/SkyEmu/issues/39

[x] (GBC) https://github.com/skylersaleh/SkyEmu/issues/66

[x] (GBA) https://github.com/skylersaleh/SkyEmu/issues/77

[x] (GBA) https://github.com/skylersaleh/SkyEmu/issues/78

[x] (GBC) https://github.com/skylersaleh/SkyEmu/issues/79

[x] (GB) https://github.com/skylersaleh/SkyEmu/issues/58

[x] (GBC) https://github.com/skylersaleh/SkyEmu/issues/28

[x] (GB) https://github.com/skylersaleh/SkyEmu/issues/31

[x] (GBC) https://github.com/skylersaleh/SkyEmu/issues/71

[x] (GBC) https://github.com/skylersaleh/SkyEmu/issues/70

[x] (GBC) https://github.com/skylersaleh/SkyEmu/issues/48

[x] (GBC) https://github.com/skylersaleh/SkyEmu/issues/106

[x] (GBC) https://github.com/skylersaleh/SkyEmu/issues/67

Pass/Fix 25 more test roms

[x] https://github.com/skylersaleh/SkyEmu/issues/104

[x] (GB/GBC) blarg/halt_bug.gb

[x] (GB/GBC) blarg/instr_timing.gb

[x] (GB/GBC) blarg/interrupt_time.gb

[x] (GB/GBC) blarg/mem_timing/01-read_timing.gb

[x] (GB/GBC) blarg/mem_timing/02-write_timing.gb

[x] (GB/GBC) blarg/mem_timing-2/01-read_timing.gb

[x] (GB/GBC) blarg/mem_timing-2/02-write_timing.gb

[x] (GB/GBC) blarg/oam_bug/1-lcd_sync.gb

[x] (GB/GBC) blarg/dmg_sound/01-registers.gb

[x] (GB/GBC) blarg/dmg_sound/02-len_ctr.gb

[x] (GB/GBC) blarg/dmg_sound/03-trigger.gb

[x] (GB/GBC) blarg/dmg_sound/04-sweep.gb

[x] (GB/GBC) blarg/dmg_sound/06-overflow_on_trigger.gb

[x] (GB/GBC) blarg/dmg_sound/11-regs_after_power.gb

[x] (GB/GBC) blarg/cgb_sound/01-registers.gb

[x] (GB/GBC) blarg/cgb_sound/02-len_ctr.gb

[x] (GB/GBC) blarg/cgb_sound/03-trigger.gb

[x] (GB/GBC) blarg/cgb_sound/04-sweep.gb

[x] (GB/GBC) blarg/cgb_sound/06-overflow_on_trigger.gb

[x] (GB/GBC) blarg/cgb_sound/08-len_ctr_during_power.gb

[x] (GB/GBC) blarg/cgb_sound/09-wave_read_while_on.gb

[x] (GB/GBC) blarg/cgb_sound/11-regs_after_power.gb

[x] (GB/GBC) blarg/cgb_sound/12-wave.gb

[x] (GB/GBC) daid/ppu_scanline_bgp.gb (GBC)

[x] (GB/GBC) daid/stop_instr.gb (DMG)

[x] (GB/GBC) mooneye/acceptance/bits/unused_hwio-GS.gb

[x] (GB/GBC) mooneye/acceptance/call_cc_timing.gb

[x] (GB/GBC) mooneye/acceptance/if_ie_registers.gb

[x] (GB/GBC) mooneye/acceptance/jp_cc_timing.gb

[x] (GB/GBC) mooneye/acceptance/oam_dma_timing.gb

[x] (GB/GBC) mooneye/acceptance/oam_dma/sources-GS.gb

[x] (GB/GBC) mooneye/acceptance/oam_dma_restart.gb

[x] (GB/GBC) mooneye/acceptance/ppu/intr_1_2_timing-GS.gb

[x] (GB/GBC) mooneye/acceptance/ppu/stat_irq_blocking.gb

[x] (GB/GBC) mooneye/acceptance/timer/tim00.gb

[x] (GB/GBC) mooneye/acceptance/timer/tim00_div_trigger.gb

[x] (GB/GBC) mooneye/acceptance/timer/tim01.gb

[x] (GB/GBC) mooneye/acceptance/timer/tim01_div_trigger.gb

[x] (GB/GBC) mooneye/acceptance/timer/tim10.gb

[x] (GB/GBC) mooneye/acceptance/timer/tim10_div_trigger.gb

[x] (GB/GBC) mooneye/acceptance/timer/tim11.gb

[x] (GB/GBC) mooneye/acceptance/timer/tim11_div_trigger.gb

[x] (GB/GBC) mooneye/emulator-only/mbc1/bits_mode.gb

[x] (GB/GBC) mooneye/emulator-only/mbc1/bits_ramg.gb

[x] (GB/GBC) mooneye/emulator-only/mbc1/ram_256kb.gb

[x] (GB/GBC) mooneye/emulator-only/mbc1/ram_64kb.gb

[x] (GB/GBC) mooneye/emulator-only/mbc1/rom_16Mb.gb

[x] (GB/GBC) mooneye/emulator-only/mbc1/rom_1Mb.gb

[x] (GB/GBC) mooneye/emulator-only/mbc1/rom_2Mb.gb

[x] (GB/GBC) mooneye/emulator-only/mbc1/rom_4Mb.gb

[x] (GB/GBC) mooneye/emulator-only/mbc1/rom_512kb.gb

[x] (GB/GBC) mooneye/emulator-only/mbc1/rom_8Mb.gb

[x] (GB/GBC) mooneye/emulator-only/mbc2/bits_unused.gb

[x] (GB/GBC) mooneye/emulator-only/mbc2/rom_1Mb.gb

[x] (GB/GBC) mooneye/emulator-only/mbc2/rom_512kb.gb

[x] (GB/GBC) samesuite/apu/channel_3/channel_3_wave_ram_locked_write.gb

[x] (GB/GBC) samesuite/ppu/blocking_bgpi_increase.gb

[x] (GB/GBC) cpp/ramg-mbc3-test.gb

All non emulation bugs fixed

[x] Resolved an issue that could cause a BIOS to not be loaded if it was in the same directory as the executable

[x] Fix crashes on bad paths to ROMs

[x] Memory Leaks (https://github.com/skylersaleh/SkyEmu/issues/65)

Other

[x] Made noise emulation more accurate

2 Improvements to Test / Development Infrastructure

[x] Enabled GBEmulatorShootout for automated testing of the GB core

[x] Enabled continuous integration of a development branch and a 2 stage repo to allow for more aggressive merging of features without worrying about breaking the public builds, and to make regression testing more efficient.

Notes: GBEmulatorShootoutComparison
opened by skylersaleh 83
Android Build

Currently a WIP. This pull request is so that we can engage the build workers in the continuous integration environment.

This doesn't produce a valid build yet.

opened by skylersaleh 32
Scooby doo classic creep capers minor graphics glitch.

Dr Jekyll's head keeps flickering in visibility.

Updated correct screenshot. Other emulators have this too, might be glitched on hardware as well. This persists, even while using the official bios.
help wanted gb

opened by jmc92 4
Android port version?

I know there's already a web version, but i prefer for this multiple Gameboy emulator have a stand alone app version for android. And play games fully offline. The osc is really bad too. I really like your idea with that emu and the app icon looks cute. Please consider porting this to android.

opened by DavidAriyan 3
[BUG?][WEB version][IOS15] can't running

but the 微软Edge it can runnig. safari will cash

Error: TypeError: Argument 1 ('shader') to WebGLRenderingContext.shaderSource must be an instance of WebGLShader url: blob:http://172.20.10.5/a4833a2e-bc6e-4f04-a360-71ef20c468f9 line: 8010 column: 23 error: TypeError: Argument 1 ('shader') to WebGLRenderingContext.shaderSource must be an instance of WebGLShader

opened by nenge123 3
Various Memory Leaks

I left SkyEmu running in the background and left my laptop unattended for around 9 or so hours, and go back to it and see SkyEmu has crashed (generic 0xc0000005 exception). Not only that, but other applications seem to have crashed, like Firefox and HexChat.

Looking at the Event Viewer shows warnings on low virtual memory, with SkyEmu taking a wooping 43282735104 bytes of memory, which seems to indicate a memory leak someplace (and would explain why other applications crashed, they probably didn't like running out of memory).

opened by CasualPokePlayer 3
Need for speed flickering graphics on title menu

There's about 3-5 pixels in a long strip at the bottom of the menu on Need for Speed - Porsche Unleashed that keeps flickering, on the screen where you have all the options after pressing start.

This persists, even while using the official bios.
bug gba

opened by jmc92 3
[Feature Request] Android Native Build

This issue is to track the feature request for an Android Native build to create SkyEmu.apk

In theory the current code base supports this, but the CI infrastructure and build system need updates to produce the android apks.

This request was forked out of this issue: https://github.com/skylersaleh/SkyEmu/issues/36#issue-1300935444
enhancement good first issue

opened by skylersaleh 2
【GB】Add LFSR for noise channel

Adds emulation for the linear-feedback shift register that is used to generate pseudeorandom noise for the noise channel in the Game Boy's sound processor.

opened by Powerlated 2
Text corruption in Lufia

This seems to be caused by spurious hflip flags being included on the tile data for the text background layer.

Tracing through DMA and cpu memory transactions, there is two potential culprit writes from the CPU, both by PC (0x0807a4f2):

The disassembly of the game ROM seems to show a complex expression leading to those writes.

Best guess currently is this is caused by incorrect latching/open bus emulation, as this value may be created by ORing a previous value onto itself, and there is portions in the game where VRAM seems to be being cleared with open bus values.

opened by skylersaleh 2
Reduce Duplication

File Browser Super Mario Advance 4 - Super Mario 3 + Mario Brothers (Japan) (Rev 2) sdcard/New Folder/Super Mario Advance 4 - Super Mario 3 + Mario Brothers (Japan) (Rev 2)

why make it show 2 same file names

my suggestion Super Mario Advance 4 - Super Mario 3 + Mario Brothers (Japan) (Rev 2) sdcard/New Folder

or Just show only one Current Path at the top the other file names text warp
enhancement

opened by soundsnow 0

Releases(v2)

v2(Oct 23, 2022)
It is my pleasure today to announce the release of the SkyEmu v2 GBA/GB/GBC emulator.

You can access the web build here or download the native builds linked at the bottom.

Lets take a look at some of the new features in this release:

Display Options

SkyEmu v2 adds 5 high quality upscaling shaders covering the most popular upscaling algorithms. All filters are antialiased so they look nice at a variety of resolutions and the LCD filters even adapt themselves to the characteristics of the screens of the HW being emulated. For example when playing a DMG game the LCD filter's pixel outline color changes and its sub-pixel grid is replaced with a slight drop shadow.

On top of the upscaling shaders SkyEmu v2 adds a bunch of scaling and display emulation options:

Forced Integer Scaling

Stretch to Fit Scaling

Color Correction

Screen Ghosting

Screen Rotation

Customizable DMG GB Color Palette

The GBA color correction uses a new algorithm that tries to recreate the characteristics of the popular AGS-101 screen, and like the shaders, the color correction and ghosting adapt automatically to the system of the game being played.

Improved Save States

The save state system was substantially beefed up compared to v1. Save state capture/restore can be bound to keyboard and joypad button presses. The Save states are now saved to the disk and persist across app launches, switching games, and future SkyEmu versions. And, the save states are even encoded into png images that show screenshots of the game when the save state was taken. This makes it easy to manage, organize and share save states, as you can see what they contain even without opening SkyEmu. The picture below is a real, working, save state from SkyEmu v2.

Compressed ROM loading

Because of popular request, SkyEmu can now load ROMs directly from .zip files without unzipping them first. When loading a .zip file SkyEmu will autodetect the correct system for the ROM inside and place save states/files on the same folder that contains the zip.

Improved GameBoy and GameBoy Color Emulation:

Rewritten APU and PPU

Significantly more accurate audio and graphics emulation

Supports mid-scanline effects

Supports mid tone PSG writes

Can now run complex games like Prehistorik Man with correct audio and video

Added support for RTC emulation (allows for day/night cycle in Pokemon among other things)

Added support for booting GB/GBC Boot ROMs:

Enabled by adding one of the following files to the folder with the game ROM:

GBC Boot ROMs: "gbc_bios.bin" "cgb_boot.bin", "cgb0_boot.bin", "cgb_agb_boot.bin"

GB Boot ROMs: "dmg0_rom.bin", "dmg_rom.bin" "gb_bios.bin"

Running a GB game with a GBC Boot ROM enables colorizing the GB games and palette selection by holding a direction on the D-pad just like a real Game Boy Color

Fixes for > 50 edge case test roms

Increased Accuracy

The following games have confirmed fixes in SkyEmu v2:

(GBA) Final Fantasy Tactics: Fixed in game save

(GBA) Top Gun Combat Zones: Fixed bug that prevented being able to start the game

(GB) Alleyway World (GB): Fixed a bug that prevented the users input from being able to move the paddle

(GB) Pokemon Red: Fixed corruption on game loading screen

(GBA) 007 Everything or Nothing: Fixed audio screeching

(GBA) Beyblade V-force - Ultimate Blader: Fixed audio clicks/pops

(GBA) Beyblade V-Force - Ultimate Blader Jam (USA) audio click/pops Issue #61

(GBA)Golden Sun - Depth issues Issue #45

(GBA) ATV Quad Power Racing unplayable. Issue #55

(GBA) Konami Krazy Racers (USA) missing tracks during the intro Issue #63

(GBA) Mario Kart - Super Circuit: track renders incorrectly Issue #39

(GBC) Action Man - Search for Base X (USA, Europe) (gbc) crashes out straight away Issue #66

(GBA) Golden Sun don't save Issue #77

(GBA) GBA Golden Sun...Sleep Mode does not work Issue #78

(GBC) Survival Kids (GBC) intro sequence has wrong color pallette Issue #79

(GB) Zen - Intergalactic Ninja (USA) graphics glitch Issue #58

(GBC) Warriors of Might and Magic (USA) (En,Fr,De) GBC corrupt hud Issue #28

(GB) Speedy Gonzales (USA, Europe) corrupt hud during gameplay Issue #31

(GBC) 007 - The World Is Not Enough (USA, Europe) glitchy HUD Issue #71

(GBC) Fli-Plasma (PD) [C] glitchy line at top of screen Issue #70

(GBC) Doesn't pass the test made by Demotronic GBC demo Issue #48

(GBC) Binary Chaos (PD) [C].gbc flashing screen and freezes up Issue #106

(GBC) Ready 2 Rumble Boxing (USA) (Rumble Version) (GBC) stuck on the title screen Issue #67

Source code(tar.gz)
Source code(zip)
SkyEmu-v2-Linux.zip(6.97 MB)
SkyEmu-v2-macOS-universal.dmg(4.45 MB)
SkyEmu-v2-Windows.zip(1.38 MB)
v1(Oct 14, 2022)
SkyEmu v1

SkyEmu is a low level GameBoy, GameBoy Color and Game Boy Advance emulator. Its primary focus is to provide a good user experience through a good mixture of tradeoffs of accuracy, performance, features and usability.

Features

Highly accurate Game Boy Advance emulation

Game Boy and Game Boy Color Emulation

Experimental Nintendo DS support (only capable of running homebrew currently)

Cross Platform: Windows, MacOS, Linux, Web App (with touch screen controls for iOS and Android)

Game Controller and Rumble Support with configureable keybinds

4x Save Slots with screenshot preview

Game fastforward and rewind support (supporting very long rewind times)

Support for emulating the Real Time Clock

CPU, MMIO, and Memory Debuggers

Dark and Light Themes

Support for loading official BIOSs dumps

Source code(tar.gz)
Source code(zip)
SkyEmu-Linux.zip(6.43 MB)
SkyEmu-macOS.dmg(2.38 MB)
SkyEmu-Windows.zip(1.26 MB)