GBS 8200/8220 CFW Project

[Cyber Akuma]

Oh tell me about it, my first one worked but had a constant white dots noise, this one is pretty much perfect, for DOS i can set the refresh rate to 60Hz apparently which would mean finally sharp DOS recording, i'm still kind bothered by the fact that 70Hz doesn't work though.

I am guessing that the "brand" you buy it from on Amazon or whatever does not matter as even within the same "brand"/seller quality can vary wildly?

[Iraito]

Oh tell me about it, my first one worked but had a constant white dots noise, this one is pretty much perfect, for DOS i can set the refresh rate to 60Hz apparently which would mean finally sharp DOS recording, i'm still kind bothered by the fact that 70Hz doesn't work though.

I am guessing that the "brand" you buy it from on Amazon or whatever does not matter as even within the same "brand"/seller quality can vary wildly?

It's a bit luck of the drawn but i noticed that the yellow buttons models after modding are pretty much always devoid of noise.

EDIT: Also little update, the GBS paired with VGA240.EXE for changing the refresh rate of DOS games to 60Hz gives off the best quality for DOS capturing that i have ever witnessed

[Josh128]

What is VGA240.EXE?

[Iraito]

What is VGA240.EXE?

https://github.com/joncampbell123/doslib

It's part of a large library of dos utilities, VGA240 in particular changes the refresh rate of DOS to 60Hz to make capturing way easier, it's a really unknown utility that doesn't impact compatibility or visuals and yet barely anybody uses it for DOS video capture.

[Zaca]

How well would having PS2-> GBS-C -> OSSC -> Monitor work? I've just been using the OSSC with my PS2 and whilst its playable the flickering you get from bob de interlacing can get distracting.

[NoAffinity]

How well would having PS2-> GBS-C -> OSSC -> Monitor work? I've just been using the OSSC with my PS2 and whilst its playable the flickering you get from bob de interlacing can get distracting.

It'll work fine. The processing lag of both devices will be additive but it is still very playable, imho. Less than 2 frames I would guess.

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[kitty666cats]

What are you doing with the GBS and the OSSC? 480p from GBS line doubled to 960p from OSSC? Using OSSC on pass through as an analog to digital converter? I’ve done the latter setup before (1080p from GBSC passed thru OSSC) and had good results. The VGA input on my Plasma sucks and doesn’t work with anything but computer resolutions.

Hey what’s the “URL” for the web interface, btw? I completely forget. 1.192.168… something? I have a new phone and now I can’t connect to my GBS

[NoAffinity]

192.168.4.1

Theres other url's too, can be found on the github.

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[Zaca]

What are you doing with the GBS and the OSSC? 480p from GBS line doubled to 960p from OSSC? Using OSSC on pass through as an analog to digital converter? I’ve done the latter setup before (1080p from GBSC passed thru OSSC) and had good results. The VGA input on my Plasma sucks and doesn’t work with anything but computer resolutions.

I was planning on trying 480p from GBS line doubled to 960p from OSSC, the additional lag isn't a big concern since I'll probably not even notice it.

Also I appreciate the help

[SuperSpongo]

192.168.4.1

That's not always the case, though, it is router/network dependent. Mine is 192.168.1.22, for example. Easiest way to tell is to login to your router and check the connected devices list.

[maxtherabbit]

What are you doing with the GBS and the OSSC? 480p from GBS line doubled to 960p from OSSC? Using OSSC on pass through as an analog to digital converter? I’ve done the latter setup before (1080p from GBSC passed thru OSSC) and had good results. The VGA input on my Plasma sucks and doesn’t work with anything but computer resolutions.

Hey what’s the “URL” for the web interface, btw? I completely forget. 1.192.168… something? I have a new phone and now I can’t connect to my GBS

it's whatever your local DHCP server assigns to it

[NoAffinity]

192.168.4.1

That's not always the case, though, it is router/network dependent. Mine is 192.168.1.22, for example. Easiest way to tell is to login to your router and check the connected devices list.

It is 192.168.4.1 for direct connection to the esp in AP mode prior to joining it to a network. You have to join the gbscontrol wifi first. These also work, according to the github:
http://gbscontrol (or http://gbscontrol:80) (or http://gbscontrol.local)

Once the gbs is joined to a wifi network, the device you are opening the web ui on needs to be joined to the same network as the gbs. The below work in that case too.
http://gbscontrol (or http://gbscontrol:80) (or http://gbscontrol.local)


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[SuperSpongo]

Ah, gotcha!
Yeah, when I connect to the GBSC's own network for initial setup I always use http://gbscontrol.local
This doesn't work anymore, once I let it join my network, unfortunately. I will have to try out the others from the wiki

[kitty666cats]

Thanks, fellas! I’ll have to bust mine back out soon. It’s a very nice GBS-8220 (dual output variant!) thrown together by NoAffinity, aka GBSensei

Very nicely put together with plastic standoffs, but tossed into a sloppy-looking plastic project box from the local electronics store with I/O holes cut out with a hacksaw by yours truly

—————

I’ve noticed an unfortunate trend online of people assuming GBSC units will also function well as a pure transcoder - which it CAN for 31+ kHz, but everyone I see doing this tends to be using it with PS2, laden primarily with 480i games! It seems that lots of people aren’t made quite aware that you can’t properly pass interlace through these things… or maybe 1080i works? IDK? But the only stable 15kHz one is gonna get out of these is a forced 240p.

It makes me wonder - would interlaced output be possible with enough rama-esque sorcery? Or are these TVIA (or whatever the brand is, I forget) units locked to progressive out no matter what?

[NoAffinity]

^correct, interlaced output is not possible, presumably due to the tvia. I dont know the mechanics entirely, but no interlaced output is possible.

^^once joined to a network, the eps' local network is no longer broadcast (goes into client mode instead of ap mode). Not sure if that's your issue, but thought it worth mentioning. Its either join the eps' wifi and login via wifi, or join it to a external wifi network and access it through wired or wifi connection via a device that is also on the external network, but never both. For example, I joined my gbs to a wifi network, and access it via a hard wired desktop that is on the same network as the wifi router that the gbs is joined to.

Separate from that, if you are doing all things correctly, the signal to/from the eps can get garbled due to noise from surrounding components. Soldering a vertical antenna of some sort to the eps' antenna which natively lies flat on its pcb, can help overcome this.

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[rabidgerry]

Ferrite bead on charge pump.(replace R58)
Charge pump decoupled with 100n cap.(Between R59 and R58)

Sorry to bring up ancient mods for the GBS8220 but I wanted to get some clarification on the charge pump mod. I swap out r58 with a ferrite bead of 100-120 ohms right, then do I use a 100nf capacitor or do I use a 1uF capacitor like the Retro RGB guy says in his links on this video https://www.youtube.com/watch?v=fmfR0XI5czI


100nf capacitor and 1uF capacitor are obviously not the same values as a believe 100nf is 0.1uf.

If anyone can clear this up for me that would be great.

[NoAffinity]

I followed the github instructions. My 8220 is the cleanest output I'd the 3 or 4 gbs controls that I've built for myself over time.

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[Keith Bress]

Sorry if this is a stupid question, but does the GBS-C actually support scaling to a 1600x1200 output? I seem to be hearing different answers on this. I've been told that 1280x960 is the max supported 4:3 output rersolution while others have said 1600x1200 is supported.

Thanks!

[BuddahLova]

For shits and giggles I bought one of those GBS C units from Retroscaler on Aliexpress to try it out.

Not to my surprise, it doesn't seem to give me an output. Just to make sure I'm not missing anything it should just automatically output a signal right? Any signal at all.. I get nothing, tested with all connections, diff consoles and diff monitors.

[NoAffinity]

1280x1024 is max 4:3 output. 1280×720 is 16:9. 1920x1080 is a 16:9 canvas with 4:3 image.

^yes it should just work as long as your source is good and connected correctly. If they've put a permanent 100ohm resistor across rgbs sync to ground, vga may not work.

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[BuddahLova]

1280x1024 is max 4:3 output. 1280×720 is 16:9. 1920x1080 is a 16:9 canvas with 4:3 image.

^yes it should just work as long as your source is good and connected correctly. If they've put a permanent 100ohm resistor across rgbs sync to ground, vga may not work.

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Cheers, I can see the LED show the stats of the signal correctly so I assume the inputs are working. Have tried multiple resolutions for each of my consoles but still don't get anything to output, both through the hdmi and vga connections.

[NoAffinity]

Are you able to get into the web ui? Might be some settings that can be changed to help. Are you able to see if the esp lights up? Bad esp's wont light up and are a semi common issue.

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[Keith Bress]

1280x1024 is max 4:3 output. 1280×720 is 16:9. 1920x1080 is a 16:9 canvas with 4:3 image.

^yes it should just work as long as your source is good and connected correctly. If they've put a permanent 100ohm resistor across rgbs sync to ground, vga may not work.

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Thanks for the clear answer. I think 1280x1024 is technically 5:4. Are there black bars on the top and bottom or does the GBS-C apply a slight vertical stretch?

[BuddahLova]

Are you able to get into the web ui? Might be some settings that can be changed to help. Are you able to see if the esp lights up? Bad esp's wont light up and are a semi common issue.

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Yep am able to get into the web ui and I can indeed see the esp light up when settings are changed or when console is turned on.

Still, could be a dodgy esp or even clock generator I'm leaning towards

[NoAffinity]

In the web ui:

Try the rgbhv/component toggle (you want it set to rgbhv always)

Try messing with Frame Time Lock and Switch Lock Method

Try the Reset Sync Processor button - the esp light should flash off momentarily when it resets.

Try Sync Watcher

And of course there is always Reset Default + Restart. Might just want to try this one first.

What consoles are you using? If any are 480p, try the pass through preset (and/or the same with any 240p sources IF your screens support 240p)



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[BuddahLova]

In the web ui:

Try the rgbhv/component toggle (you want it set to rgbhv always)

Try messing with Frame Time Lock and Switch Lock Method

Try the Reset Sync Processor button - the esp light should flash off momentarily when it resets.

Try Sync Watcher

And of course there is always Reset Default + Restart. Might just want to try this one first.

What consoles are you using? If any are 480p, try the pass through preset (and/or the same with any 240p sources IF your screens support 240p)



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Tried nearly every setting, still no output. Tried PS1 + PS2 via SCART and a Dreamcast through VGA, the device displays the specifications of the signal correctly, debug screen shows its receiving it.

If you been thinking about getting one of these units, learn from my example!

[NoAffinity]

Do you have separate scart cables for the ps1 and ps2? Ps2 is RGsB when outputting via scart? GBS Control does not support RGsB. And if you're using the same cable for both, it's possible the cable is set up for RGsB which also wont work with ps1. Add that to the possibility that the assembler included the 100ohm resistor on rgbs sync->ground which would render the vga input unusable, and you may have an explanation for none of the consoles working with your unit. But maybe the 100ohm resistor is switchable?

I may just be grasping at straws here tho. If you have tested the ps1 and its cable successfully elsewhere then that console should at least work with the gbs.

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[NO_ob]

Just saw this on aliexpress while looking for famicom stuff looks like a new all in one solution
https://www.aliexpress.com/item/1005004341800340.html

[captaineos]

@NO_ob Fascinating ingenuity of Aliexpress sellers on display. Unclear if the HDMI output is derived from the RGBHV output, I have to assume so which isn't ideal. Page 22 of the TVIA 5725 datasheet describes Analog RGB/YUV Input with 16bit and 24bit Digital Output Modes; it would be nice if these clones had an engineer write up specifically their enhancements or modifications.
I would be looking for them to include switchable TTL voltage attenuation as the absolute max is 3.3-3.6v. The excess voltage above that is clamped by ESD protection diodes that also reference to the chip's internal voltage in leading to spikes in noise.

Another thing they could optimise is either higher quality RGB input potentiometers or defaulting to 75-ohm termination.

EDIT: Just found this - https://gamescare.com.br/produto/gbs-co ... ler-1080p/
Guys don't seem to be selling their addon board separately but nice try I guess.

[Keith Bress]

Does anyone know if the GBS-C, the RT5X, or any other scaler is capable of "cropping" a 720x480p signal to 640x480 with a 1:1 PAR? It would be useful for systems like Gamecube/Wii and Xbox on fixed-pixel EDTVs. Sure the aspect ratio would be slightly off, and you'd lose some picture information on the sides, but most of those games are designed with overscan in mind anyway.