r/SBCGaming

I recently built a pair of RetroArch shaders that try to recreate the original display characteristics of the first-generation Game Boy and the backlit GBA SP AGS-101.

Many handheld shaders begin with an imagined “retro screen” color and then blend a few previous frames to create ghosting. That can look nostalgic, but nostalgia is not always accuracy.

Some Game Boy shaders become extremely bright green. Others look more like a generic calculator or electronic-organizer LCD than an original Game Boy. Both may feel old, but they are still interpretations of what people remember an old screen looking like.

I wanted to approach the problem differently.

Here are two screenshots with my Game Boy shader enabled. The first scene exposes row and column crosstalk, while the falling piece in the second image makes the LCD response and ghosting easier to see.

https://preview.redd.it/71j5mhvtfdkh1.png?width=2046&format=png&auto=webp&s=7e939fbd923bf198fc91c9d71e77992c06d9e45d

My approach can be summarized in four words:

Measure first, then calculate.

For color, I used measured and color-managed reference data for the original displays, including their color, grayscale and black-level behavior. That data is then converted correctly to sRGB instead of being approximated with a green tint.

On a reasonably accurate sRGB display, the result should therefore be much closer to the original screen colors—not simply someone’s memory of what a Game Boy looked like.

The second part is the display model itself.

A real LCD does not create ghosting by blending several complete frames. Each liquid-crystal pixel has a previous state, receives an electrical drive signal and takes time to move toward its next state. Bright-to-dark and dark-to-bright transitions do not necessarily happen at the same speed.

My shader first converts the game image into simulated electrical drive values. It then calculates how the virtual liquid-crystal pixels respond over time while preserving their previous states.

For the original Game Boy, the model also accounts for the shared row and column drive structure of its passive-matrix screen. This means ghosting, crosstalk and residual images are produced by the evolving display state rather than being painted over the final image as a blur effect.

The GBA SP AGS-101 uses a very different type of LCD, so I built a separate model for it. Its pixels respond faster, but different color and brightness transitions still have different response characteristics. Its measured color behavior, black level, scanning and pixel structure are handled separately from the Game Boy model.

The comparison below shows raw emulator output on the left and the AGS-101 shader on the right. The difference is not only saturation: the color balance, black level, tonal depth and pixel appearance all change.

https://preview.redd.it/pe1yosc6gdkh1.png?width=2040&format=png&auto=webp&s=774b5dfb3e5f5a1f40bcb2829bbbba37669125c2

The models were not tuned only by eye. During development, I used original display measurements, drive and timing information, historical LCD research, and experimental data from similar materials and panels from the same era.

Where complete original panel data no longer exists, I used historically appropriate research to constrain the model instead of inventing values based on appearance alone.

All screenshots in this post were rendered in RetroArch on a KONKR Pocket Advance and captured directly from its 960×640 framebuffer:

- GBA content uses an exact 4× mapping from 240×160 to 960×640.
- Game Boy content uses an exact 4× mapping from 160×144 to a 640×576 viewport.

These are direct captures of the shader’s GPU output on the handheld, not photographs of its physical panel.

The project is now open source and can be used with RetroArch. Download it, extract it into the RetroArch shaders directory, and load the appropriate preset. Any frame-mixing option inside the emulator core should be disabled so the temporal response is not calculated twice.

GitHub and download: https://github.com/JohnnySun/retro-display-lab

The Brick Hammer definitely has a nicer screen(images don’t reflect it) and nicer buttons but I found myself struggling when on the go and being more careful on how I stored/placed in my bags. it definitely looks nicer and the buttons are much better. This will become my one handed gaming device or RPG centric for now. looks nicer on my desk too with my display stand.

The RG SP is so nice to just shut and put away anywhere. no worry about having to put a certain way in my bag etc. It’s hard to say if it can take over the Brick as primary retro handheld but definitely enjoying platformers it.

Tl;dr: Flippad won't fit phones if the USB port is not in the center.

I know it's gonna sound obvious to most people, but I'm dumb and maybe there are other dumb people out there that this might be of some use.

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I really liked the Gamesir Taco form factor, something truly pocketeable to give my phone physical controls. I ordered one, and took 5min upon arrival to realize the dpad was catastrophically bad and beyond fixing.

The 8bitdo Flippad was the 2nd best thing (not a fan of all front buttons, especially the menu button right under your thumb), so I ordered one too. It just arrived, and took 30s to realize I made a very basic miscalculation.

My phone is a foldable so the USB port is towards the back and not the center like most normal phones. For some reason I expected the Flippad USB connection to be more flexible to allow for that, but... it isn't at all.

Well, at least it was cheap. But I said the same thing about the Taco, and I ended up with paying not a lot for zero usable controllers.

really tried to like the stock OS, after an hour of unplayable slowdowns with final burn neo & amiga cd32 it's time to move. Going back to my fav on 40xx-v & 34xx - which is - muOS. 'Andromeda' build is still in the works, but it's beautiful, here's a short sneak preview

The Brick Hammer definitely has a nicer screen and nice button but I found myself struggling when on the go and being more careful on how I stored/placed in my bags. it definitely looks nicer and the buttons are much better. This will become my one handed gaming device or RPG centric for now. looks nicer on my desk too with my display stand.

The RG SP is so nice to just shut and put away anywhere. no worry about having to put a certain way in my bag etc. It’s hard to say if it can take over the Brick as primary retro handheld but definitely enjoying platformers it.

Edit 2: More pic in comment sections with more details. Feel free to ask me more questions!

Edit: pics of back in different angles to showcase how lighting changes how the shell looks.

Back looking more transparent:

https://ibb.co/84dMWbVr

Held at a different angle looking more frosted, same lighting:

https://ibb.co/tPwP3RMZ

Wow! I’m blown away so far in every aspect of just unboxing and booting this up.

Highlights so far:
- the weight is perfect! Doesn’t feel too heavy nor cheap & light. An excellent premium feel!
- the buttons are great! Yes they are less rounded then something like a Miyoo Mini BUT are not sharp. Think NES angles but slightly convex, my fingers glide just fine. It’s nothing like the sharpness on a PS Vita LCD version. Those bug tf out of me.
- the buttons are also big enough to where I don’t need them bigger, they feel juuuuust right. Also not loud, I love these buttons!
- triggers are good, I’m not an expert in these so can’t really say anything til I test them but so far no complaints. The tiny etched texture on the shoulder buttons are way smaller than pictures make it out to be and don’t feel rough, kinda smooth tbh but can keep your fingers in place. I dig them!
- D-Pad is so PS Vita like and that’s a HUGE PRO! I love my Vita’s D-Pad and this is coming from someone that grew up on NES & SNES in the late 80’s & early 90’s and prefers old school membranes. I’m gonna jump the gun and say this is one of the best D-Pads I’ve ever tried along with my favorites like OG SNES, 8Bitdo M30 2.4ghz (buttery smooth!), Xbox One “polygon” pad w/ micro switches (just wish it was as quiet as these) and the just acquired Gamesir Tegenaria Lite (it’s what the PS1 should of been).
- joysticks feels just right. I need to test them on games but so far just playing with them I’m happy. As long as you’re not playing with the tips of your thumbs then ergos won’t be much of an issue plus the edges grip your skin where you can adjust to them in the base of your thumbs. 👍🏻
- ergonomics are good to almost great. Too early to say if it’s perfect but no issues so far. The corners are wonderfully curvy. I have the spare back plate and will try it in the future but I’m liking the flat back. Gonna see if that suits me more vs more bumps.
- the speakers with how I hold them are not blocked. That was a big concern from online reviewers but that’s not my case. Even when I put my thumbs slightly over them they still sound clear. YMMV.
- the shell is WAY less frosted than what online pictures make it out to be. In the right light yes it can get frosty and with the bumpy extra back shell away from the device it is a frosty white but with the black parts on the Nova it’s less so. As you can see the pics I took are in my bedroom around sunset. With the screen on at night on my white bed comforter you can see through plenty enough and is more of a mixture of a light grey with white highlights. I’m so happy I sticked with this shell as the black boarder for the OLED really sells the premium look. The back is also less frosty and darker than expected. With my phone screen over it on certain angles it actually gets closer to the renders online. Love it!
- the OLED is the star of the show! I just put on some random YT HD video that show cases lots of games on full screen and man it just pops! This will be a shader enthusiast’s portable dream!!! The black borders makes the device disappear and gets you more immersed vs seeing the flashy shell.
- after staring at the OLED screen the frosted shell & clear buttons are starting to grow on me cause they disappear in the background. It’s where I’ll be okay with not swapping out the buttons cause I’m digging them more and more(but I’m gonna anyways for you guys cause I love ya). They are more grey than white and so far any regret about this crystal colorway is going away more and more.
- speakers sound okay to good. Not muffled but more “tame” and retro games sound alright. I can tell a good DSP will take this to another level but don’t worry they sound just fine how they are as I prefer them less in your face. Maybe up the bass a bit and clean it up some more then they will shine.
- the fan on quiet mode and smart (haven’t pushed it yet) is barely audible in a room with everything turned off (I mean it has to be dead silent) but since it’s summer and I always have some sort of fan on me it’s not there. If you have any sort of noise around you like from the device, TV, fan on low or even a window/door open outside you will not hear it. On Sport mode yes it sounds like a tiny jet preparing to take off but I mean you will have to like push this device hard to even need this setting and if it gets there then just put on headphones or up the speaker volume. Off or quiet is the way to go.
- the carrying case is fitted for both flat and rounded back shells so no worries there. Feel solid and so glad I got it so I can just toss my Nova where ever and be worry free of damaging it

Just make sure to use a high quality screw driver/bit before you unscrew it after reading others have trouble. Don’t have one? I’d suggest you invest in one for future handhelds, the Nova alone is worth the investment.

I will get back to you later on how this plays and will be testing the latency as well since I’m very sensitive to input lag and why I didn’t buy these retro handhelds in the past. It ruins the experience for me and I rather play them at home on my PC, Steam Deck and Mister vs being frustrated on-the-go. Update: I posted a comment below about playing and lowering the input lag and… yeah it rocks! Go check it out!

This is my first retro handhelds purchase but I actually bought a Miyoo Mini Plus and a Mini Flip right after from discovering they have one of THE lowest input lag compared to what has been tested out there. FYI a Gameboy DMG and Gameboy Advance have an avg of 33ms and the Miyoo test at an avg of 48ms! With run-ahead/preemptive frames on GB, NES and SNES feels so snappy to play! I hope I get these same numbers on the Nova, I will be thrilled if this matches the Miyoo’s numbers or maybe match the Steam Deck as that is snappy af!

Any ways feel free to ask me any questions about the device itself. I won’t be able to test games on it til maybe tomorrow around midnight.

Using the Gamesir X5 Lite matches well with the phone. Been playing the android ports of Tomb Raider and Red Dead Redemption. As well as playing Resident Evil Code Veronica X with HD Texture pack on Nethersx2 and Resident Evil Director's Cut with HD Texture on Duckstation.

Satisfied so far!

I know it's not the best deal just hope it can help out a few of you. Normal price is $229. Sad times indeed.

Told my wife I wanted this for my birthday and to order it ASAP because it will take a while. She didn’t believe me and had to print out the order conf as the gift LMAOO🤣 cant wait for it to arrive!

Edit: I know she paid for the useless Worry-feee protection but she didn’t know better and I didnt tell her to not include that in the case she ordered it which she did so it is what it is