Retro-Go: Emulator launcher with improved emulators

[ducalex]

Retro-Go is a multi-emulator firmware with a simple launcher (strongly inspired by pelle7's go-emu).
Go-Play "Triforce" was used as a base.

Systems:

• NES
• Game Boy
• Game Boy Color
• Game & Watch
• Sega Master System
• Genesis/Mega Drive (WIP)
• Game Gear
• Colecovision
• PC Engine
• Atari Lynx
• SNES (WIP)
• DOOM

Features include:

• In game menus
• Smoother/faster transitions
• Adjust RTC and preserve time between plays
• Launcher style is customizable
• Favorites
• Hide unwanted emulators
• PAL region support (NES/SMS)
• Full speed PCE emulation
• Improved game compatibility
• More palettes (NES/GB)
• More scaling options
• Bilinear filtering
• Fixed many crashes
• Easy to build
• Save state screenshot
• And more!

Details:
I encourage you to read the README to see the key bindings and more details.

Code, assets, and releases:
Releases: https://github.com/ducalex/retro-go/releases
Cover art: https://github.com/ducalex/retro-go/releases/tag/1.19
Repository: https://github.com/ducalex/retro-go

Preview:


Problematic games list (Updated 2022-10-30):

• NES: Many MMC5 games (Incomplete mapper support) Fixed but disabled for now due to performance issue
• NES: Gun-Nac (U) - fb0ec3b9 - (Menu option text on title screen is unreadable, not rendered correctly) Confirmed
• NES: Pacman Championship Edition - (Sound doesn't work correctly) Confirmed
• NES: GI Joe - 1D2D93FF - Music some times work and sometimes not.
• NES: Battletoads - Doesn't work past level 2.
• NES: Battletoads Double Dragon - Unplayable. Confirmed
• NES: TMNT 3: Manhattan Project - Status bar jumps around because of irq timing issues. Confirmed
• GBC: Mario 6 Coins DX (romhack) (Doesn't load) In progress
• GB: Daedalian Opus (freezes after start) Confirmed
• PCE: Lode Runner (Japan) - (Loads but won't start the game after showing Stage: 1) Confirmed
• PCE: New Adventure Island -(Level 1-3 the rock sprite is garbled) Confirmed
• PCE: Legendary Axe II, The (U) -(Status bar and screen jumps up and down) In progress
• PCE: Dungeon Explorer - (hangs after title screen)
• PCE: Cadash (U) - a3eb340c - (troubles showing the sprites and status bar. They are just briefly visible now and then, blinking)

Please report any other issues!

Only the most recent releases are listed below. Older releases are available here.

[Nemo1984]

This is so much better! Thank you!

[ripper121]

How much of your code is from pelle7?
EDIT: ok found it.

Acknowledgements
The emulators code was originally from the "Triforce" fork the official Go-Play firmware.
A few lines of code were taken from go-emu by pelle7, as well as the esthetics was copied.

[deecee]

Thanks a lot for keeping up the development of new emulators for the Odroid Go.

[ripper121]

Its no new emulator. Its "only" a new UI.

[ducalex]

How much of your code is from pelle7?

The vast majority of the code is original and predates his project. The battery drawing function is about the only code taken verbatim but many other places were inspired by go-emu. You could say it's a spiritual successor.

Replicating the GUI allowed me to finally release this project, before everybody moves to the GO Advance!

[ducalex]

A new release (2020-02-05) is available.

• Fixed Game Gear aspect ratio
• PNG support for cover art (it also still supports Go-Play format)
• Option to reduce cover art loading delay
• (Very) Experimental ZIP support for NES/SMS/GG ROMS

Download: https://github.com/ducalex/retro-go/rel ... 2020-02-05 (The .fw is also attached to this thread)

[Nemo1984]

This is amazing! If you could do the same scaling trick on gb/gbc, I would be very happy! Like fullscreen stretch. This screen is small enough.

Thanks!

[ducalex]

This is amazing! If you could do the same scaling trick on gb/gbc, I would be very happy! Like fullscreen stretch. This screen is small enough.

Thanks!

I've added a new scaling option to fill the screen. It is only applicable to Game Boy as the others already fill the screen.

Unfortunately the Gameboy doesn't share the same display code as the Sega/NES emulators. For now I have made a basic scaler but I hope to reuse what is in place eventually which would give a softer image.

I have published the new release on Github (download here) but consider it beta!

[Nemo1984]

I am so happy right now! Thank you so much for your work, I'm glad my sketchy Tirforce was usefull for something!

I have tested a few roms. Abolutely no issues to report.

EDIT: I seem to have a savestate bug. Like, it's going to load the savestate whether I want it or not.

[ducalex]

EDIT: I seem to have a savestate bug. Like, it's going to load the savestate whether I want it or not.

Thanks, it is now fixed! I'm attaching a build to this post if you want to test, otherwise I will probably make a new release in a few days.

Few more changes in that build:

- Scaling setting is now correctly remembered per emulator
- Added a "Scale" option to scaling that respects the emulator aspect ratio, in case someone doesn't like the corrected/stretched Game Gear or NES
- 8MB GBC games are now supported

[Nemo1984]

I have done some more testing with the new version. I didn't find any bug.

It's a great version!

[ducalex]

Since no other issues were reported I have uploaded a new release. Nothing major since the last attached test build.
Changes since previous release:
- Scaling modes
- 8MB GBC game support
- Significant size reduction (Only useful if you use my multi-firmware, it frees up 2MB)
- Bug fixes

It is attached to the top post, or go to https://github.com/ducalex/retro-go/rel ... 2020-02-11


Edit: Let me know if you have feature requests, the next release should be a feature release!

[Nemo1984]

It is so nice that you optimized the size! (Partitions?). I can do so much more with the multiboot! I have seen some multiplayer code floating around? Wishful thinking?

Anyways. Big fan.

[ducalex]

Yes I reduced the padding space in partitions a bit, but more importantly I replaced the SD Card error images (saves 300KB per emulator) and removed pre-computed emulation tables in SMS (saves 250KB) and some misc stuff.

Multiplayer would be interesting! The GB Link is doable but for the others I imagine it would depend on the esp32 bluetooth latency. Ideally I'd need two consoles to develop and debug. In January I have ordered a second GO but I also bought a GO Advance at the same time so who knows when they'll finally ship

[Nemo1984]

I think I saw a wifi nes multiplayer emulator and a C64 one. All wifi.

[ducalex]

I found the NES one viewtopic.php?f=159&t=33689&p=247807 which is very promising.

It seems to sync inputs on every frame. I don't know if that would be enough for a good experience in all games however. Many games use PRNG (to spawn enemies and so forth) so both consoles could end up in very different states after a while...

[Nemo1984]

I found the NES one viewtopic.php?f=159&t=33689&p=247807 which is very promising.

It seems to sync inputs on every frame. I don't know if that would be enough for a good experience in all games however. Many games use PRNG (to spawn enemies and so forth) so both consoles could end up in very different states after a while...

Yes, that's the one I tried with my brother. It does work for a while, then it just stop syncing. I don't know if it is possible to make it fully working.

[ducalex]

I'll experiment with input syncing inspired by the experimental multiplayer NES but I think I'll also try streaming the video to the guest console.

[lordhardware]

Speedups are missing in GB when compared to Pelle7's go firmware launcher.

Apart from that very nice!

[jafox]

I don't know if it's possible to add partial screen updates for the gameboy emulator like the one made by Paspartout and Unorthodactyl. even so thank you very much for the effort

[Nemo1984]

I have noticed you are removing the interlace. This was a fix for the screen ripping in nes and others.

[ducalex]

Speedups are missing in GB when compared to Pelle7's go firmware launcher.

I have added speedups 2x 3x for all three emulators. There is a link to a test build at the end of this post if you want to try now!

I don't know if it's possible to add partial screen updates for the gameboy emulator like the one made by Paspartout and Unorthodactyl. even so thank you very much for the effort

I have tried using the partial update code from the NES/SMS and the results weren't good, full rendering caused less tearing.
Do you have a link to their emulators so I can see what they did different for the gameboy?

I have noticed you are removing the interlace. This was a fix for the screen ripping in nes and others.

The interlacing was enabled only in the NES, it was disabled in SMS/GG and not present at all in GB/GBC.

I couldn't find a game that suffered from my removal, could you give me an example I could try? I don't mind adding it back and improving it instead of removing it if it's really necessary!

You can download a test build of commit 1d40f6a, it contains the interlacing changes and the speed control.

[ducalex]

I have noticed you are removing the interlace. This was a fix for the screen ripping in nes and others.

I have added back the interlacing code but before enabling it I want to try something else. It seems to work well but can you please test this build and tell me if the results are worse, equal, or better than interlacing?

I don't know if it's possible to add partial screen updates for the gameboy emulator like the one made by Paspartout and Unorthodactyl. even so thank you very much for the effort

I figured out a way to make it work, I think. This experimental build contains partial GB updates.


The experimental build with both partial GB update and anti-tearing can be downloaded here: https://send.firefox.com/download/7ec3a ... xXl_o1M2lQ

[Nemo1984]

I like the new anti-tearing, it works as good as interlacing but without the blur. Really an improvement!

[concreted]

This is by far my favorite launcher and the experimental 2/17 build is working great for me - performance on GB is super smooth now. My biggest complaint with the Go was GB performance being not-quite-there and I'd almost given up hope on it being improved. Great work!

The "scale" option in GB no longer has blur though which looks worse to me because of inconsistent pixel sizes. Would be nice to be able to toggle blur.

Another longstanding issue with the other emulators is a freeze bug in GBC Metal Gear Solid, if you have any chance of looking into that I would be very happy viewtopic.php?t=31541

Thanks for your continued work on the Odroid Go, I'm happy to test/give feedback on new versions.

[ducalex]

The "scale" option in GB no longer has blur though which looks worse to me because of inconsistent pixel sizes. Would be nice to be able to toggle blur.

Agreed, a bilinear filter is planned and will probably be in the next release.

Another longstanding issue with the other emulators is a freeze bug in GBC Metal Gear Solid, if you have any chance of looking into that I would be very happy

I'll have a look into it!

Thanks

[ducalex]

New release 2020-02-19!

Changes:
- GB/GBC: More of the ROM is preloaded to fix stuttering in some games
- GB/GBC: Now using partial screen updates, allowing 60fps in many games
- Turbo speed support in all emulators
- Removed interlacing. The replacement method looks better (or at least equal) and works for all three systems
- Launcher: File extensions are now hidden

Known issues:
- The GBC partial updates cause rendering weirdness in Megaman Xtreme where the lightning effect is rendered as the screen half white

Postponed changes:
- Multiplayer support is postponed until I get my second GO. I can only test so much with a computer (and it's not fun)
- An optional bilinear filter to reduce shimmering caused by scaling but I want to see how the recent changes work for everybody first
- Sound in turbo modes. I got it to work, but to get it to sound good (albeit sped up) is another issue completely

Let me know if you like/dislike any of the changes and please report any bug found

[Nemo1984]

Thank you for your work!

I have been having trouble with Worms on GBC for a while now. I believe it might be related to the partial update. If you can't fix it, I don't mind sacrificing that game.

I have also noticed that ucity for gbc now crashes. We seem to have lost some compatibility. The last test version also does that.

EDIT: I have narrowed it down to when the firmware shrank. Something that was necessary for some games has been removed from the gbc emulator.

Link to UCity (open source simcity clone for GBC) https://github.com/AntonioND/ucity

[concreted]

On 2-19, I'm seeing GB running in "Full" scaling mode on start even if previously changed to "Off" or "Scale". In past releases I think it would remember the last used setting.

One thing I've noticed in 2-19 and 2-17 when testing Link's Awakening DX is that full-screen transitions from look very smooth when scaling is "Off", but a little choppier when scaling is "Scale" or "Full". Moving objects on a single screen look smooth regardless of scaling. I see something similar in Super Mario Land where the horizontal scrolling is slightly choppier when scaling is not "Off".

Will keep testing it out, thanks for the great releases!

[Nemo1984]

The scaling bug seems to be present on all platforms.

[lordhardware]

Performance in GBC is substantially improved in games with single direction scrolling like Donkey Kong.
Mario Tennis looks incredible now when in over world or more static screens, still a bit of slowdown during camera tracking of the ball diagonally, however definately more playable than ANY previously released version of the console.

I'd be happy to gift you a second Odroid Go if you have any working netcode examples

[ducalex]

I have also noticed that ucity for gbc now crashes. We seem to have lost some compatibility. The last test version also does that.
EDIT: I have narrowed it down to when the firmware shrank. Something that was necessary for some games has been removed from the gbc emulator.

Thanks for narrowing it down, it was in fact the 8MB support in that same release that caused the issue. It is now fixed!

On 2-19, I'm seeing GB running in "Full" scaling mode on start even if previously changed to "Off" or "Scale". In past releases I think it would remember the last used setting.

Thanks for the report, that's now fixed!

I'd be happy to gift you a second Odroid Go if you have any working netcode examples

That's very generous! I have already ordered one in January but it hasn't shipped yet .


I am attaching to this post an experimental/untested (2020-02-21-exp) build with the above fixes and a temporary new option to select the update mode:
- Auto: Current mode, it automatically decides when to do partial or full
- Full: Always do full updates
- Partial: Always do partial updates

The setting is remembered per emulator.

Auto is meant to be the best performance/rendering compromise. However it certainly needs tuning so if a game works better in full or partial please report it!

Thank you all for testing

[Nemo1984]

ucity works flawlessly now! Worms doen't work properly, but it never did regardless of the firmwares or settings. I guess it's just not fully compatible.

I really appreciate what you did with that firmware!

[ducalex]

Worms doen't work properly, but it never did regardless of the firmwares or settings. I guess it's just not fully compatible.

Can you tell me the exact game name and issue? I tested Worms Armageddon and it seems to work fine but I never played a full game.

[Nemo1984]

Worms doen't work properly, but it never did regardless of the firmwares or settings. I guess it's just not fully compatible.

Can you tell me the exact game name and issue? I tested Worms Armageddon and it seems to work fine but I never played a full game.

That's the one. When I use the air strike or move the map to see other worms, the terrain doesn't follow so the worms are floating everywhere.

[Paspartout]

Nice work! Just found this now and its working great! Thanks.
I really like how there is a clear menu now that prompts if you want to save and quit or just quit when you press menu button.
Every emulator launcher I tried had a different behaviour on menu button. While one saved the state the other one made you hold the menu button to save. This is much better and one thing I wanted to do myself at some point(now I don't have to anymore )
Also glad that you got the partial updates working. I remember it being tricky to decide when to frame skip but the Auto mode seems to work nicely in your build. It makes playing some games much more enjoyable.

Here are some suggestions and a bug report:

- When setting the gameboy emulator to full brightness(5/5) and switching to the menu it dims the light and vice versa. The values itself seem to be set properly though.
- When switching GB pallettes it would be nice to have a preview. I think we just unpaused the game for one frame to do that.
- One minor thing would be to remember the position in the options menu. If you wanna tweak a specific item that would make things easier.
- Another minor thing would be having brightness, volume and pallete wrap around, so can do pallete 7->0 with a single press. Its kinda matter of taste though doing it like this.
EDIT:
- Having a reboot to firmware option when pressing menu button in the launcher would be nice as well!

[ducalex]

@Paspartout
I fixed the brightness bug and implemented most of your suggestions. I also agree with remembering the menu position but it's more involved than it appears so I'll do it later!

@Everyone
A new release is available (2020-02-23). No new major features but I will have less time for a while and I wanted to share the latest improvements.
It contains many bug fixes and a 5-10% fps increase ("full" now reaches 33 fps, which is the max we can possibly achieve on this hardware).

It's attached to the top post or download here!

I'm currently working on linear/bilinear interpolation (filters) and I will also look into the broken GB games mentioned in this thread.

[Shumafuk]

I would love to have this launcher on Odroid Go Advance. Simple and effective.

[Nemo1984]

I have found a minor bug. Sometimes, when you exit a game, the speaker will emit a hiss. It seems random.

Thanks!

[ducalex]

I have found a minor bug. Sometimes, when you exit a game, the speaker will emit a hiss. It seems random.

Thanks!

I can't reproduce but I've added code to disable the speaker more forcefully when the emulator stops AND when the launcher starts, can you test this build see if it helps?

Thanks

[Nemo1984]

I have found a minor bug. Sometimes, when you exit a game, the speaker will emit a hiss. It seems random.

Thanks!

I can't reproduce but I've added code to disable the speaker more forcefully when the emulator stops AND when the launcher starts, can you test this build see if it helps?

Thanks

Yup, that fixed it. Many thanks!

EDIT: I have found a small bug in the menu. When you set a volume level in game, you can't lower it direcly in the menu after you exit the game. You have to raise it again and then lower it. It only does that on level 4. Very strange.

[ducalex]

Another longstanding issue with the other emulators is a freeze bug in GBC Metal Gear Solid, if you have any chance of looking into that I would be very happy viewtopic.php?t=31541

Could you provide a save game to reproduce the bug? The link for the save is dead and the video seems to imply the bug occurs an hour into the game which is a bit too long for me.

EDIT: I have found a small bug in the menu. When you set a volume level in game, you can't lower it direcly in the menu after you exit the game. You have to raise it again and then lower it. It only does that on level 4. Very strange.

Thanks for narrowing it down, it is now fixed . As a side note: I've got Worms Armageddon to work! I'm attaching a build to this post if you want to help me test (and more importantly see if I broke other games in the process). It took forever to debug so I haven't tested much myself yet.

[concreted]

Could you provide a save game to reproduce the bug? The link for the save is dead and the video seems to imply the bug occurs an hour into the game which is a bit too long for me.

Sure, please try the attached save. After loading hit the Up button on the right side of the elevator and you should see it crash a few seconds after the elevator starts moving.

[Nemo1984]

Here are the problems I found with this test:
1942: Scrolling clouds are wonky on intro
Toy Story Racer: Unplayable, Sprites errors
Obelix: Crashes
Oracle of ages: Wonky scrolling background in intro. Was a bit weird with the previous release, but not as bad.
Oracles of seasons: Wonky intro. Again, was a bit weird with the previous release, but got worst.

It's a no go for me. It is unfortunate.

Thank you for your work!

[ducalex]

Could you provide a save game to reproduce the bug? The link for the save is dead and the video seems to imply the bug occurs an hour into the game which is a bit too long for me.

Sure, please try the attached save. After loading hit the Up button on the right side of the elevator and you should see it crash a few seconds after the elevator starts moving.

Thanks that's perfect, I can replicate the crash.

Here are the problems I found with this test:
1942: Scrolling clouds are wonky on intro
Toy Story Racer: Unplayable, Sprites errors
Obelix: Crashes
Oracle of ages: Wonky scrolling background in intro. Was a bit weird with the previous release, but not as bad.
Oracles of seasons: Wonky intro. Again, was a bit weird with the previous release, but got worst.

It's a no go for me. It is unfortunate.

Thank you for your work!

Thank you for the variety, it will make debugging easier. So far they all seem affected by the same interrupt. Can you confirm that Worms is playable? Worst case scenario I can do a game-specific check.

[Nemo1984]

Worms is playable! No more bugs. While the worms are a bit jumpy while scrolling(might have been how it originally ran) everything works great! Thank you!

[Nemo1984]

I have done some further testing with the worms fix.

Donkey Kong Country. Language selection music plays way too fast.
Donky Kong Land III: Unplayable. Sprites errors.
Shantae: Unplayable. Sprites invisible.

[ducalex]

@Nemo1984
I've narrowed down the Worms issue further and applied the fix elsewhere. It seems to have fixed the previously mentioned games.

@concreted
I have also fixed Metal Gear Solid!

I'm attaching an experimental build to this post for those who want to test .

[concreted]

Metal Gear Solid works for me! This is awesome, finally get to keep playing this game. Thanks for your great work! I'm so happy this is finally working on the Go.

I tested this build with Shantae and noticed some rendering differences with the yellow clouds coming out of the water in the heal rooms. On the 2-23 build the clouds are pretty static and don't flicker, whereas in this build the clouds flicker a lot at inconsistent intervals. I never played on an actual console so not sure, but I think the clouds are supposed to flicker to simulate transparency - so this current build seems more correct, but the inconsistency is distracting. It's perfectly playable as is but curious if you think there are possible improvements here. I've included a save where you can see this, just walk right from where the save loads.

Will try other games and let you know if I notice anything else. Thanks again