GBS 8200/8220 CFW Project

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Cyber Akuma
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Re: GBS 8200/8220 CFW Project

Post by Cyber Akuma »

I'm still pretty lost on how to do some of the modifications to the GBS8200, namely for the capacitors and SCART.

There are three modifications I could use some help on understanding:

https://github.com/ramapcsx2/gbs-contro ... od-Library

1: The wiki mentions "Add 10uf / 22uf ceramic SMD capacitors in parallel to stock ones (x4) C23, C41(alternative: C43), C42, C48"

They show it being done here: https://github.com/ramapcsx2/gbs-contro ... capacitors

Does this mean to use a capacitor between 10uf and 22uf? Or am I supposed to get both 10uf and 22uf and use them on the specific points? They don't mention if all three caps are the same and I can just use the same cap to stack all three or if I need different capacitance ratings for them. And if they are all the same, would it be better to use a 10uf or 22uf? I am not sure in this situation if less capacitance or more would be better. Do I just buy these from somewhere like DigiKey or Mouser? Not entirely sure which ones to buy.

The wiki also mentions "Let's settle on 10uF for the large local storage caps, as more capacity seems to be at the upper end of current market offers. We want as high a voltage rating as possible, but that increases size. We want to limit size to 0805, so they can still be soldered besides the 0603 stocks. Ebay has some cheap listings for: 0805: 10V 0603: 6.3V Actual voltages are 3.3V for the main supply (C23 C41 C48), and 1.8V for the digital supply (C42)." So does this mean that C23/41/48 use the same caps but C42 needs a different cap? It mentions buying 10V and 6.3V caps... but the actual caps are 3.3V and 1.8V? Not sure what goes where.

2: Likewise, it also mentions "Remove C11, optionally replace with 22uF (6.3V to 16V) electrolytic cap"

Well, I would like to replace the capacitor instead of just removing it. But it wants me to replace a non-polarized ceramic cap with a polarized electrolytic one. How would I know the proper orientation for the electrolytic capacitor? I tried to find videos of this but nobody seems to have installed an electrolytic one in place of C11, if they removed C11 at all. I could really use some help figuring this one out. (Also, I assume I would not be able to install a SMD version since the traces would not line up?)

3: And finally for SCART, it's about the resistor: "Add 100ohm resistor across sync and ground for RGBs input"

Is this only needed if I use a SCART to VGA adapter? Or would I still need to add this resistor somewhere even if I wire the SCART into the RGB input headers? From my understanding the resistor is needed for connecting consoles from SCART to VGA, but would cause problems connecting an actual VGA signal from a PC this way? So if the resistor is only needed if using the VGA port then it would be ideal if I could use the RGB header and leave the VGA port alone without causing any conflicts between consoles and PCs. But if I need it then I want to figure out a way to install it without permanently effecting PC VGA input.
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NoAffinity
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Re: GBS 8200/8220 CFW Project

Post by NoAffinity »

1) 10uf caps. Solder them side-by-side with the existing caps at each location. 0805 or 0603 works fine. They need to be rated for what the circuit is measured at, at a minimum, at each location. 6.3v and 10v are commonly readily available in the sizes noted and will work for all.
2) yes, remove c11 and replace with an electrolytic cap. Negative goes to ground.
3) the 100 ohm resistor is needed for console rgbs input, should be removed when inputting rgbhv. Doesnt matter if it's there or not when inputting ypbpr. You can get a connector and pins that will plug onto the 5-pin connector, make a resistor connection between the sync and ground pins (cut resistor legs, solder resistor to the pins, insert pins into the connector). Go back enough pages, I posted some pics of how I did this and a link to order the parts. Others simply twist the legs of the resistor around the two pins, making it a figure 8 shape that can be easily removed. Theres pictures herein of that as well.

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Cyber Akuma
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Re: GBS 8200/8220 CFW Project

Post by Cyber Akuma »

NoAffinity wrote:1) 10uf caps. Solder them side-by-side with the existing caps at each location. 0805 or 0603 works fine. They need to be rated for what the circuit is measured at, at a minimum, at each location. 6.3v and 10v are commonly readily available in the sizes noted and will work for all.
That makes it a lot easier, thanks. So I can just use 0805 10v 10uf ceramics on all four points? That's thankfully a lot simpler to do.

Would the method of soldering to the back of the board as shown in the last image on that page work or even be recommended? I am worried about soldering directly to surface-mount components since in the past when I tried years ago I just wound up tearing them off the board and frying them on the iron.
2) yes, remove c11 and replace with an electrolytic cap. Negative goes to ground.
Thanks. I still wasn't sure what end was positive/negative though, but then I ran into this:

https://jbretro.wordpress.com/2020/10/2 ... sterclass/

Specifically this image at the end: https://i.imgur.com/n5SNJZS.jpg

So I am supposed to solder the electrolytic cap directly to the legs of that voltage regulator instead of on the bare pins of where C11 used to be? I assumed I would have to solder it in place of C11, but I had no idea what pad was what polarity to do that. Would leaving C11 bare and soldering it to that VRM be the same thing?

By the way, could I get advice on what would be a good quality capacitor to use? Places like Mouser and Digikey have a dizzying selection and I don't know where to start, there are several random cheap ones on Amazon but I have no idea if they are any good, and I saw some with the brand "NTE" at Microcenter if those are good... even if a little pricy.
3) the 100 ohm resistor is needed for console rgbs input, should be removed when inputting rgbhv. Doesnt matter if it's there or not when inputting ypbpr. You can get a connector and pins that will plug onto the 5-pin connector, make a resistor connection between the sync and ground pins (cut resistor legs, solder resistor to the pins, insert pins into the connector). Go back enough pages, I posted some pics of how I did this and a link to order the parts. Others simply twist the legs of the resistor around the two pins, making it a figure 8 shape that can be easily removed. Theres pictures herein of that as well.
I see, so regardless of which input/header I use for my consoles I would need to install that 100 ohm resistor if I am just getting straight RGB over SCART out of them.

And yeah, I saw the RetroRGB video do the same trick by twisting the pins of the resistor to work as a sort of hoop over the two pins. You mean like what is shown at the 9:53 min mark here? https://youtu.be/fmfR0XI5czI?t=592

I was hoping to do something a bit more robust and permanent though. Would I be able to solder the resistor to the wiring of the SCART/RGB header itself so it would only effect that SCART/RGB header input, or does it have to be across those two pins on the board itself? And if so, can I instead solder in both a resistor and a switch to turn the resistor on/off for what kind of input I am using? Or would that somehow cause problems to have a switch enable/disable the resistor between those pins?

Thanks for helping me understand what to do with the capacitors.
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Kez
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Re: GBS 8200/8220 CFW Project

Post by Kez »

Cyber Akuma wrote: Thanks. I still wasn't sure what end was positive/negative though, but then I ran into this:

https://jbretro.wordpress.com/2020/10/2 ... sterclass/

Specifically this image at the end: https://i.imgur.com/n5SNJZS.jpg

So I am supposed to solder the electrolytic cap directly to the legs of that voltage regulator instead of on the bare pins of where C11 used to be? I assumed I would have to solder it in place of C11, but I had no idea what pad was what polarity to do that. Would leaving C11 bare and soldering it to that VRM be the same thing?
Yeah, that's the same thing. Ground is easy to find on a board with a multimeter, just do a continuity check between somewhere that you know is ground and the pad - the one that beeps is ground. In this case it's quite clear to see anyway, if you look at the left part of the picture you linked, you can see that the right C11 pad is part of a large plane of copper whereas the left pad has a single trace leading to it. This is a strong indication that the right pad is ground (though checking with a multimeter is best if you're not sure).
Cyber Akuma wrote: I see, so regardless of which input/header I use for my consoles I would need to install that 100 ohm resistor if I am just getting straight RGB over SCART out of them.
...
I was hoping to do something a bit more robust and permanent though. Would I be able to solder the resistor to the wiring of the SCART/RGB header itself so it would only effect that SCART/RGB header input, or does it have to be across those two pins on the board itself? And if so, can I instead solder in both a resistor and a switch to turn the resistor on/off for what kind of input I am using? Or would that somehow cause problems to have a switch enable/disable the resistor between those pins?
Yeah, a switch would work fine. A simple on-off switch in series with the resistor.
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Cyber Akuma
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Re: GBS 8200/8220 CFW Project

Post by Cyber Akuma »

Kez wrote: Yeah, that's the same thing. Ground is easy to find on a board with a multimeter, just do a continuity check between somewhere that you know is ground and the pad - the one that beeps is ground. In this case it's quite clear to see anyway, if you look at the left part of the picture you linked, you can see that the right C11 pad is part of a large plane of copper whereas the left pad has a single trace leading to it. This is a strong indication that the right pad is ground (though checking with a multimeter is best if you're not sure).
I see, thanks. I don't know much about circuit design so I wasn't aware that large areas of that board like that are generally ground planes. And now that you mentioned it, I can also see that what I assume is the positive pad of C11 has a small trace directly linking to the other pin of that VRM as well.
Yeah, a switch would work fine. A simple on-off switch in series with the resistor.
Ok. So just to make sure I have it right. I solder an on/off switch to the "sync" and "ground" pins of the 5-pin ECA/CGA inputs near the VGA input, which would be the bottom-2 post pins.... but I just make sure to put a 100 ohm resistor somewhere along the two wires of the switch like in this picture right? It shouldn't make any difference if I solder the resistor to the Sync or Ground side I am guessing?

https://i.imgur.com/MFHjQwJ.jpg
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NoAffinity
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Re: GBS 8200/8220 CFW Project

Post by NoAffinity »

^yes that will work for the switch. You can solder it to the bottom of the board for a clean install.

Wrt soldering the caps to top of board vs bottom of board - best practices for soldering dictate that you should hold heat to whatever you're soldering for no more than 2 seconds. If you're having to hold it any longer without getting good solder flow, you're doing something wrong. Refer to soldering 101, 102 etc videos. A little flux will help things flow nicely as well. Flux one side of the existing cap that you will be soldering to. Tin the side of the new cap that you will be soldering to the existing cap. Use some esd tweezers to hold the new cap in place while you apply heat. Should flow and get a good metallurgical bond in a second or less. Then just flux the other ends with both caps now firmly anchored in place. Apply a little bit of solder to your tip and apply to the other ends. The flux will help the solder to flow and bond across both surfaces.

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Cyber Akuma
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Re: GBS 8200/8220 CFW Project

Post by Cyber Akuma »

NoAffinity wrote:^yes that will work for the switch. You can solder it to the bottom of the board for a clean install.

Wrt soldering the caps to top of board vs bottom of board - best practices for soldering dictate that you should hold heat to whatever you're soldering for no more than 2 seconds. If you're having to hold it any longer without getting good solder flow, you're doing something wrong. Refer to soldering 101, 102 etc videos. A little flux will help things flow nicely as well. Flux one side of the existing cap that you will be soldering to. Tin the side of the new cap that you will be soldering to the existing cap. Use some esd tweezers to hold the new cap in place while you apply heat. Should flow and get a good metallurgical bond in a second or less. Then just flux the other ends with both caps now firmly anchored in place. Apply a little bit of solder to your tip and apply to the other ends. The flux will help the solder to flow and bond across both surfaces.
Thank you, I needed those tips.

One other thing that just came to mind, while I am ordering the new capacitors, I figured it might be a good idea to also order replacements for the same caps on the board in case I manage to lift the cap off the board like in previous attempts from years ago. Do you know what are the specs of those caps already on the board that I would be soldering to so I can order replacements of those too if I screw up?
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NoAffinity
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Re: GBS 8200/8220 CFW Project

Post by NoAffinity »

There are no schematics that I'm aware of. Dont think I've ever seen Rama's math on how he arrived at 10uf/22uf providing the desirable capacitance range at those locations. Failing any of that, you'd have to pull them off and measure them with an esr meter.

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Cyber Akuma
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Re: GBS 8200/8220 CFW Project

Post by Cyber Akuma »

Huh, never heard of an ESR meter before. Had to look them up, quite an interesting device. Some of them can be had for surprisingly cheap. But can these only work by removing the capacitor first? There is no way to analyze or test the capacitor in-circuit?
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NoAffinity
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Re: GBS 8200/8220 CFW Project

Post by NoAffinity »

I got one similar to this one that does a pretty good job in circuit. I wouldnt trust it to tell you what the value is if you dont already know it tho.

https://a.aliexpress.com/_mKEpRAO

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Cyber Akuma
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Re: GBS 8200/8220 CFW Project

Post by Cyber Akuma »

Interesting, I recall seeing that same one as the cheapest ESR Meters on Amazon too:

https://www.amazon.com/HiLetgo-Multifun ... 01MYU0QI3/

https://www.amazon.com/Treedix-Graphica ... 087LT5766/

https://www.amazon.com/Mega328-Digital- ... 07WT9VVZB/

It can actually measure in-circuit? I tried finding info on that before and wasn't able to. Although, if it still can't accurately measure the capacitor then there isn't much point. The whole reason I would need one would be to know what the capacitors are in case I manage to melt them off the board and need to replace them when attempting to solder other caps or wires to them.
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NoAffinity
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Re: GBS 8200/8220 CFW Project

Post by NoAffinity »

Ah, cool. Didnt realize these were available on amazon now.

It can measure in circuit, but again, I wouldnt rely on it unless you already know the value and are just looking to confirm it. I don't know all the voodoo witch doctory of in circuit measuring, others could probably chime and and provide better insight, and truthfully it's probably a discussion for a different thread. From my experience with my tester, hower, it works about 90% of the time for in circuit measurement, and its really just to see if the component is close to being within spec. Eliminates having to pull all components in the circuit,l and/or helps hone in on the problem component, but there is still a margin of error.

All that said, removing the original caps to measure them isnt hard. Use a solder wick to get most of the solder off each side. Then apply some flux to both sides and position your solder tip so it heats up both ends of the cap at the same time. Should come right off. And again, some decent esd tweezers (around $15 on amazon) are good for grabbing the cap as soon as it comes loose.

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Cyber Akuma
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Re: GBS 8200/8220 CFW Project

Post by Cyber Akuma »

Yeah, I guess this is starting to turn more into electronics support than talking about the GBS8200 modification. Thank you though, you have been extremely helpful in trying to figure out what to do.
NO_ob
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Re: GBS 8200/8220 CFW Project

Post by NO_ob »

Anyone know a good brand of usb wall plug that will give me clean power? i've done all of the cap mods and stuff but still get diagonal lines scrolling across my screen a lot of the time.

Also a friend got the ODV GBS-C and on his model that haloing that was posted on the previous page only seems to happen on 1080p resolution but 720p is okay
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Cyber Akuma
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Re: GBS 8200/8220 CFW Project

Post by Cyber Akuma »

So a new question came up as I was about to buy some of the parts, namely the Si5351A Clock Gen.

I was planning to buy the official one straight from Ardafruit that has a blue PCB here: https://www.adafruit.com/product/2045

Since from my understanding the ones with the purple PCBs all over Amazon and eBay are clones. But I was also told that apparently, the blue ones don't work well with the GBS8200 and only the purple ones work properly? Can anyone give me any advice on if that is true or not? The one from Ardafruit is pretty much as cheap as the cheapest ones on Amazon yet is apparently not a knockoff, so I wanted to go with that one, but if it's not going to work then it's pointless to get that version. I tried Googling around about it but the only mention of this I could find was a single 1/5 review on Amazon that claimed it made their GBS8200 worse.... but also seemed to imply the one they got on Amazon was a knockoff of a knockoff. Only other mention I could find was an Instagram photo someone posted of their GBS8200 modded with what looked like the blue Ardafruit clockgen and they claimed it made a world of difference in fixing their screen tearing.
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Re: GBS 8200/8220 CFW Project

Post by Dreamcazman »

Cyber Akuma wrote:But I was also told that apparently, the blue ones don't work well with the GBS8200 and only the purple ones work properly? Can anyone give me any advice on if that is true or not?
The blue one's don't work, at least the one I bought didn't.

I got one of them from a local supplier as I was impatient and didn't want to wait weeks getting a board from China.

Installed it and instantly got these wavy vertical lines on the edges of the screen. The image was more stable without it!
After trying a heap of different things, with no improvement, I ended up buying a purple board, installed it and everything is now working flawlessly.

I can't say 100% whether all the blue boards will give trouble or I just got a dodgy one. If you're interested, I discussed it a few pages back - viewtopic.php?f=6&t=52172&start=4502

Get a purple board to be safe.
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Cyber Akuma
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Re: GBS 8200/8220 CFW Project

Post by Cyber Akuma »

Dreamcazman wrote: The blue one's don't work, at least the one I bought didn't.

I got one of them from a local supplier as I was impatient and didn't want to wait weeks getting a board from China.

Installed it and instantly got these wavy vertical lines on the edges of the screen. The image was more stable without it!
After trying a heap of different things, with no improvement, I ended up buying a purple board, installed it and everything is now working flawlessly.

I can't say 100% whether all the blue boards will give trouble or I just got a dodgy one. If you're interested, I discussed it a few pages back - viewtopic.php?f=6&t=52172&start=4502

Get a purple board to be safe.
I see, thanks. One of the main reasons I wanted the blue board was because Ardafruit has official ones, but if they don't work right I guess I am better off getting a random purple board on Amazon and hoping it's not a fake. Any idea of any verified sellers on Amazon that sell good ones?
Dreamcazman
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Re: GBS 8200/8220 CFW Project

Post by Dreamcazman »

Cyber Akuma wrote:hoping it's not a fake.
Does it really matter as long as it works?
Cyber Akuma wrote:Any idea of any verified sellers on Amazon that sell good ones?
Nope sorry, I got mine from this seller on Aliexpress.

https://www.aliexpress.com/item/1005001621711840.html
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Cyber Akuma
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Re: GBS 8200/8220 CFW Project

Post by Cyber Akuma »

Dreamcazman wrote: Does it really matter as long as it works?
https://www.aliexpress.com/item/1005001621711840.html
Well, that's kinda why I am worried about it. As long as it does work (and does not die on me from being made poorly) I don't care if it's a knockoff or not, especially if the real thing does not work properly.

Issue is there are so many of the same one, and usually using the same stock images, that I have no idea if they are good ones that will work or not. I tried Googling for "Si5351A Clock Generator" just now expecting to get many results of the purple one on Amazon, eBay, AliExpress, etc.... but the first link was Ardafruit's site, second was an overpriced blue one on Amazon that had said bad review on attempting it on a GBS8200, third was the blue one on Digikey.... and random other sites that to my surprise mostly had a blue one. And the ones on Amazon that are purple are different shades of purple for the ones that did not just use stock images and several also have bad reviews that it does not work properly.

The most popular purple one on Amazon also has a few 1/5 reviews about it being DOA/broken... including one that claims it did not work on their GBS but the blue one did.

So now I have no idea what will or won't work, which ones are just garbage regardless, or even if the blue one someone tried before was a knockoff and that's why it did not work as I have seen several images of someone building this with a blue one (though most are purple) or if it was a real one from Ardafruit and they genuinely don't work. I have no issues using a purple one knockoff or not if it's what the GBS8200 needs to work properly and can't work with the blue one authentic or not. Doesn't help that if the purple ones are knockoffs, they cost as much if not sometimes more than the blue one.

I don't want to wait months to get one from AliExpress and just hope that one that cheap works properly. If I actually knew what I was doing I would not be as worried since I would know how to properly test it to see if it's working or not, but I don't have much experience with modifying electronics.
Dreamcazman
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Re: GBS 8200/8220 CFW Project

Post by Dreamcazman »

Cyber Akuma wrote: I don't want to wait months to get one from AliExpress and just hope that one that cheap works properly.
You know now that the one I got is good so the other boards that seller has should be good too.

The other thing is these boards are pretty cheap so if you're worried, buy a couple, one from Aliexpress and another from Amazon, eBay, whatever.

The chances of them all being duds is like one in a million.
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Cyber Akuma
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Re: GBS 8200/8220 CFW Project

Post by Cyber Akuma »

Dreamcazman wrote: The other thing is these boards are pretty cheap so if you're worried, buy a couple, one from Aliexpress and another from Amazon, eBay, whatever.

The chances of them all being duds is like one in a million.
Like I said, if I knew how to test these to make sure they were working properly I would do that to make sure I get something that works, but I don't know how. (I also assume I would need an oscilloscope for that, which I do not have)

Is there a way I can temporarily connect the wires to the Clock Gen board (I will still solder on the wires to the GBS8200 end) to see if the board is working before soldering them in? Like with Kapton tape or something?

By the way, do you remember where you got your blue board from that didn't work? You said it was a local supplier? Do they have a strorefront or was it just a random supplier?
Dreamcazman
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Re: GBS 8200/8220 CFW Project

Post by Dreamcazman »

Cyber Akuma wrote:Like I said, if I knew how to test these to make sure they were working properly I would do that to make sure I get something that works, but I don't know how. (I also assume I would need an oscilloscope for that, which I do not have)
The only way I knew mine was working was to solder it in and then test it with a video source. I don't have an oscilloscope either.
Cyber Akuma wrote:Is there a way I can temporarily connect the wires to the Clock Gen board (I will still solder on the wires to the GBS8200 end) to see if the board is working before soldering them in? Like with Kapton tape or something?
Possibly, if you want to go to the trouble and you can make a good enough connection.
Cyber Akuma wrote:By the way, do you remember where you got your blue board from that didn't work? You said it was a local supplier? Do they have a strorefront or was it just a random supplier?
I'm from Australia, the shop was Core Electronics, an online retailer, they also have a storefront.
santiis2010
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Re: GBS 8200/8220 CFW Project

Post by santiis2010 »

Hey guys i did all the hardware mods to my GBS-Control but im still having this issue when i connect VGA or HDMI into the GBS-C, i get green horizontal lines, shaky picture, so i move the picture 1 step to the right and the image stabiliyze but i get a green vertical line on the left, on the right its like the image is stretched. So if a try to move/shift and extend the image i get purple colors.

Do you guys know how can i fix this? im using a pasive HDMI to VGA adapter from Retro RGb (Bob) amazon links: https://a.co/d/eTpya1s

Images of the HDMI to VGA to GBS-C to VGA to Component cable to TV:
Image

Image

Any way i can fix this or you guys can help me fix it?

Thank you :D
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Gunstar
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Re: GBS 8200/8220 CFW Project

Post by Gunstar »

@santiis2010 GBS-C doesn't like RGBHV (VGA) for downscaling your options are:
1) Buy a 360 component cable to connect directly to the GBS-C
2) Use an HDMI to YPbPr transcoder instead of the HDMI to VGA DAC
3) Sync combine RGBHV (VGA) to RGBS using adapters like Tim Worthington's VGA to SCART or TianFeng's HD15 to SCART, Retro RGB has an article on building a quick and dirty version for combining HV sync. You'll then need to wire up a female SCART socket for these adapters or figure out another way to get RGBS into the GBS-C
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kitty666cats
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Re: GBS 8200/8220 CFW Project

Post by kitty666cats »

To get rid of that green bar you can adjust the pre-HLL coast (or whatever it’s called) in the advanced settings, as well as the image size and image position - you’ll eventually be able to overscan the green area out and get a normal looking image. Took me some trial & error to do that for the first time
kattcool
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Re: GBS 8200/8220 CFW Project

Post by kattcool »

hi , i have built this project works great with component input but with vga the image is always green.

Any help as to what the issue could be would be greatly appretiated

many thanks
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Re: GBS 8200/8220 CFW Project

Post by Iraito »

I'm gonna try to make DOS and early windows games upscalable again, is this guide god ? https://www.cathoderayblog.com/converti ... s-control/ i know i need to create a cable to combine the sync.
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Cyber Akuma
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Re: GBS 8200/8220 CFW Project

Post by Cyber Akuma »

I figured it is safe to do this, but I wanted to check here just to make sure.

So, first thing when my GBS8200 comes in is that I am going to just test it out of the box to make sure it works first. I know it has it's own built-in menu and functions, would messing with these throw off the modifications you make later? Considering I see no mention of not to alter any of the default settings in the instructions I am assuming not, but I just wanted to make sure. I know that the ESP8266 connects to a debug pin on one of the ICs controlling the GBS8200, but I wasn't sure how much control this has, if it's just sending some override commands or if it basically fully controls the GBS8200 itself and completely takes over/disables any commands and built-in settings and menus with it's own software.

And second is testing the modifications to the board before I solder on the ESP8266 and Clock Gen. For me, the hardest part will be doing all the capacitors and soldering wires to the caps and pin legs. So before I waste time soldering on the ESP8266 and Clock Gen, I want to make sure all the modifications I make to the GBS8200 board itself didn't break it. Modifications such as removing the three color potentiometers, stacking the SMD capacitors, removing the C11 capacitor and replacing it with an electrolytic, and soldering wires to the IC pin legs and to the ends of capacitor C48.

Obviously just soldering wires to the board without having connected them to anything else first shouldn't cause any problems (Assuming I didn't short something while doing so) but it's the modifications to the caps and pots I am not sure of. I assume just simply stacking capacitors like that should not cause problems but I don't know for sure, likewise if removing C11 can cause problems or the board to no longer work on it's own. The part I am most unsure about though is removing the potentiometers and just simply shorting them, if that would provide too much current to the board on it's own.

Basically, if I do all the GBS8200 part of the modifications: removing and shorting the pots, adding all the extra stacked SMD capacitors, removing C11 and replacing it with an electrolytic, etc WITHOUT soldering on the ESP8266 and Clock Gen yet, can I still power on the GBS8200 board on it's own and test it to make sure I didn't break anything while making those modifications before I solder on the other components? Or would the board at that point require the ESP8266/Clock Gen to function at all or not get damaged? I want to make sure the GBS8200 itself is still functioning after all the modifications and I didn't manage to break it before I solder the ESP8266 and Clock Gen to it.
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NoAffinity
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Re: GBS 8200/8220 CFW Project

Post by NoAffinity »

The board out of the box is designed to work with TTL levels (arcade boards). You will want to test with an arcade board before modding.

The ESP overrides the stock firmware. It does not replace it, just overrides it. I.e. if you remove the esp and all mods after some point, the gbs will still boot to the stock firmware.

C11 is just a surge suppression improvement, if I remember correctly.

So, if you mod the board and boot with the stock firmware, not really sure what type of levels you would be putting out at that point or if it will even work. With color pots removed and shorted, and no cfw to otherwise control gain, color gain will be at max. Probably not good to run in this state for extended periods at any rate.



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Cyber Akuma
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Re: GBS 8200/8220 CFW Project

Post by Cyber Akuma »

NoAffinity wrote:The board out of the box is designed to work with TTL levels (arcade boards). You will want to test with an arcade board before modding.
I know it was made for arcade boards, but I can't use the VGA or Component inputs out of the box to test it with consoles or PCs?
The ESP overrides the stock firmware. It does not replace it, just overrides it. I.e. if you remove the esp and all mods after some point, the gbs will still boot to the stock firmware.
I see, so then it should not matter if I mess with the settings on the stock firmware as the ESP will override those with it's own regardless of what it's set to?
So, if you mod the board and boot with the stock firmware, not really sure what type of levels you would be putting out at that point or if it will even work. With color pots removed and shorted, and no cfw to otherwise control gain, color gain will be at max. Probably not good to run in this state for extended periods at any rate.
I see, so then I can't really test it without doing all of the modifications at once.
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