GBS 8200/8220 CFW Project

[kitty666cats]

** Disregard this post, derpy derpy **

[TheFellowJasper]

So I've put the 22uf capacitors to all 4 points, however this doesn't fixed the noise (which I suppose is more of a waving chekerboard rather than heat wave as I described it ealier) which apparently is caused by composite signal on sync pin. I'm gonna try CSync mod on my PSX. On PU-22 you use 680ohm resistor, however, would it be a problem if I solder few resistor in series geting slightly different 670Ω (470Ω + 2x100Ω) or 695Ω (470Ω + 3x75Ω)?

[tiochico27]

So I've put the 22uf capacitors to all 4 points, however this doesn't fixed the noise (which I suppose is more of a waving chekerboard rather than heat wave as I described it ealier) which apparently is caused by composite signal on sync pin. I'm gonna try CSync mod on my PSX. On PU-22 you use 680ohm resistor, however, would it be a problem if I solder few resistor in series geting slightly different 670Ω (470Ω + 2x100Ω) or 695Ω (470Ω + 3x75Ω)?

Did you tried Sync-on-luma?

[TheFellowJasper]

Did you tried Sync-on-luma?

That would require opening the psx side connector shell, right? I don't have any good glue right now to close it after cutting it through (it seems to be one part)

[tiochico27]

Did you tried Sync-on-luma?

That would require opening the psx side connector shell, right? I don't have any good glue right now to close it after cutting it through (it seems to be one part)

Yes, you have to open the connector shell but worth the try. I used super glue here

[NoAffinity]

So I've put the 22uf capacitors to all 4 points, however this doesn't fixed the noise (which I suppose is more of a waving chekerboard rather than heat wave as I described it ealier) which apparently is caused by composite signal on sync pin. I'm gonna try CSync mod on my PSX. On PU-22 you use 680ohm resistor, however, would it be a problem if I solder few resistor in series geting slightly different 670Ω (470Ω + 2x100Ω) or 695Ω (470Ω + 3x75Ω)?

Did you add the 22uf electrolytic at c11? Copper tape is probably needed.

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[TheFellowJasper]

Did you add the 22uf electrolytic at c11? Copper tape is probably needed.

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I forgot to mention that, but yes, I did add the cap to C11. I also forgot to mention that when I connect the PSX with the same cable directly to TV (skipping GBS) the pattern is still there but not as pronounced as when using GBS on my monitor. That's why I thought about getting either CSync or Sync-On-Luma from console.

Edit: Also, the component signal is pretty much crystal clear

[NoAffinity]

Ok good additional info. Sounds like you're getting close to sorting it out. Got any other rgb sources you can test on the gbs, for a sanity check?

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[TheFellowJasper]

Not right now, I don't have additional VGA cable to connect my PC to it. However, I'll try to dig around a DVD player around holidays and test the board with it

[nes.og]

Hello, I have a GBS HD 9800 board v5.0 and it works perfectly, before then I decided to remove an RGB potentiometer and bridge them. But after bridging - I found that the RED color was lost. I re-solder bridge lines and after that RED and GREEN signals were lost. At this moment I'm very confused because I can find any similar issue from anyone. Can somebody point me in the direction of a further investigation?

Do you have continuity over the bridge?

You can also measure the voltage before and after the bridge.

[TheFellowJasper]

Ok, so I have modified my cable to get Sync Over Luma on the Sync pic and it was it indeed, the signal is pretty much as clear as component, it seems to take longer for GBS to get stable signal however with it, checked with scratched disc that makes my PSX get stuck on white boot-up screen for a while and it gets displayed so I suppose it's just strong luma signal from white background when It's trying to lockon to sync. The only problem now left is that there appears to be a slight smudge/ghost to the right of the edges. Not too bad but visible

EDIT: However, after playing abit, it seems that the smudge problem is quite random in that it may sometimes not happen at all so I suppose is just a thing with my SCART-GBS adapter (right now it all on breadboard connected using jumper wires)

[Jon Nielsen]

Hello, I have a GBS HD 9800 board v5.0 and it works perfectly, before then I decided to remove an RGB potentiometer and bridge them. But after bridging - I found that the RED color was lost. I re-solder bridge lines and after that RED and GREEN signals were lost. At this moment I'm very confused because I can find any similar issue from anyone. Can somebody point me in the direction of a further investigation?

I had a similar problem when I was a bit rough in removing with a side cutter some leftover piece of pin after desoldering the others cleanly. Long story short, the side cutter created a scratch in the surface of the board near one of the through holes, which ended up having a small trace of solder leading up to the bridge - which grounded it.

As one of the pins of each potentiometer leads to ground, it's worth checking even if you already tested for continuity.

Another idea is to check if any small fragment of solder or potentiometer pin ended up attaching to a resistor in the area. This happened to me with my other board, but was fixed before testing.

IMO that area of the PCB is sensitive and with the entire GBS board being a bit brittle, I'll probably bridge the potentiometers on the bottom side - without removing them - if I'm building another GBS variant at some point.

[clintcronin]

I've been following this thread for a bit now and finally decided to get a gbs-8200, mod it and install gbs-control on it. I followed the wiki and bought my gbs-8200 , and used the esp12e board listed on the retrorgb site / video on gbs-control. I was able to flash the arduino module with no issues and am able to reach the gbscontrol web ui without any problem. The problem I'm having, however is no picture. Also, whenever I try to click any of the options in the gbscontrol web ui I get an error message saying "gbs board not responding!" The GBS is powering the ESP8266 with no issues and I'm pretty sure I have the SDA / SCL lines soldered in correctly ( as well as debug ) . Any ideas what the issue could be ? Thanks in advance , and thanks to Rama for all of the hard work.

esp module i'm using
https://www.amazon.com/gp/product/B07HF44GBT/ref=as_li_qf_asin_il_tl?ie=UTF8&tag=retrorgb-20&creative=9325&linkCode=as2&creativeASIN=B07HF44GBT&linkId=ecf3867b2f209400ace9bfad94d4aa37

[nes.og]

Does the GBS Control do proper pass through of 240P?

Can you use it just for 240P transcoding RGB to YPbPr or vice versa?

Any guides for all the options in the Web GUI?

Any info is appreciated, thanks!

[NoAffinity]

Does the GBS Control do proper pass through of 240P?

Can you use it just for 240P transcoding RGB to YPbPr or vice versa?

Any guides for all the options in the Web GUI?

Any info is appreciated, thanks!

You can use it for transcoding, yes. I've found the pass through profile doesnt work great, however, the "downscale to 15khz" profile does work great for 240p->240p. I dont know why that is, I just know it works.

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[nes.og]

Does the GBS Control do proper pass through of 240P?

Can you use it just for 240P transcoding RGB to YPbPr or vice versa?

Any guides for all the options in the Web GUI?

Any info is appreciated, thanks!

You can use it for transcoding, yes. I've found the pass through profile doesnt work great, however, the "downscale to 15khz" profile does work great for 240p->240p. I dont know why that is, I just know it works.

Sent from my SM-G955U using Tapatalk

Many thanks, I appreciate your response!

Looking forward to the build, I have all the components on order.

[bodine1231]

Im having a problem where the brightness seems very high. I'm downscaling 360 to my Net City and everything is super bright,I have to turn my brightness on my monitor to zero for it to be ok. I tried adjusting the gain on my phone and it helped a little bit,any clues?

[NoAffinity]

Im having a problem where the brightness seems very high. I'm downscaling 360 to my Net City and everything is super bright,I have to turn my brightness on my monitor to zero for it to be ok. I tried adjusting the gain on my phone and it helped a little bit,any clues?

You removed the brightness pots on the gbs?

Have you taken the output from the gbs to a different monitor to confirm it is the gbs and not the net city?

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[bodine1231]

Works fine on my bvm through component still can’t figure out why the brightness is jacked on my net city through vga. Yes pots are gone.

[nes.og]

Does the GBS Control do proper pass through of 240P?

Can you use it just for 240P transcoding RGB to YPbPr or vice versa?

Any guides for all the options in the Web GUI?

Any info is appreciated, thanks!

You can use it for transcoding, yes. I've found the pass through profile doesnt work great, however, the "downscale to 15khz" profile does work great for 240p->240p. I dont know why that is, I just know it works.

Sent from my SM-G955U using Tapatalk

What’s it like when playing games that switch between 480i and 240P when you aren’t upscaling?

[NoAffinity]

Works fine on my bvm through component still can’t figure out why the brightness is jacked on my net city through vga. Yes pots are gone.

What's the full chain, from source to net city, and what gbs input are you feeding? I've only had overbrightness issues when inputting signals that I knew were not properly attenuated.

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[NoAffinity]

Does the GBS Control do proper pass through of 240P?

Can you use it just for 240P transcoding RGB to YPbPr or vice versa?

Any guides for all the options in the Web GUI?

Any info is appreciated, thanks!

You can use it for transcoding, yes. I've found the pass through profile doesnt work great, however, the "downscale to 15khz" profile does work great for 240p->240p. I dont know why that is, I just know it works.

Sent from my SM-G955U using Tapatalk

What’s it like when playing games that switch between 480i and 240P when you aren’t upscaling?

Hmm not sure I've tried that one. Anyone else?

I would expect it would be seamless, especially if outputting to an analog monitor. I've stepped through captured videos frame-by-frame and there will be 1 frame of imperfect video at the resolution switch, but the output signal is unaffected.

Also, side note, a couple titles I've found on the genesis/megadrive that do not switch from progressive to interlaced but do have some kind of sync or resolution blip between various screens (title screen-> gameplay and/or gameplay->high score table): Lightening Force/Thunder Force IV and Grind Stormer. I prefer playing these on gbs instead of ossc for this very reason. With the ossc, when the transition occurs, not only is there a momentary sync loss, it is also not possible to get pixel perfection across both resolutions. The gbs handles it all seamless with it's high quality visual output and no momentary signal losses.

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[NoAffinity]

I picked up the Monoprice VGA to HDMI, quite happy with it - but I’m pretty curious about this unit right here:
https://www.amazon.com/dp/B00WAIX5S4/re ... SFbPYC0CJH

The Silicon chip in it has quite an interesting datasheet, reminds me a lot of the OSSC! The Sil8784, to be precise

https://www.latticesemi.com/en/About/Ne ... alogtoHDMI

A PDF of the datasheet can be found via some simple Googling, worth looking up (would link but my phone’s dying!)

I got one of these units. It seems to be the middle of the road between the cheap $5 dongles and the monoprice lkv-350, in terms of image quality. The below statements are the result of testing with GBS Control.

There is some noise in the image, only noticeable in bluish solid color backgrounds.

There is some ringing. Not really noticeable at viewing distances.

No noticeable lag.

This amazon unit does not pass through 240p (either in pass-through or downscale mode). The 720p and 1080p profiles both produce extremely washed out colors including black areas being overly gray. I did not try to correct for this. Seems to correlate with 16:9 output profiles?

Operating off the above assumption, the following is true for 4:3 GBS Control profiles:
-The colors are a bit washed out, although I'm able to get the most brightness on my TV out of this unit.
-For reference, I set brightness to '50' (out of 100) for standard HDMI sources like xbox 360, PS3
-I have to set brightness to '45' (out of 100) on my TV, for the $5 dongles. Anything more will start introducing gray in black areas, and the noise is more visible.
-I'm able to get to '47' with the monoprice unit
-With this amazon unit, I'm able to set it to '50'

There is some minor softening of the image - comparable to the $5 dongles, not present on the monoprice unit.

The manual that came with this amazon unit does note that it relies on VESA spec, and anything outside of VESA spec may produce undesirable results.

I'm seeing the monoprice units varying in price, but they are effectively comparable to (or better priced than) the amazon units. For the money, I would recommend the monoprice converter.

Stepping aside from the GBS Control testing, I paired the amazon unit up with a PC outputtting VGA. This PC has an HDMI output and VGA outputting simultaneously, and cloning the output @ 1024x768.
Image quality is much better in this use case. The softening is still there, but much less so...it's almost unnoticeable. The same is true for image brightness - much less so and almost unnoticeable. No noticeable noise or rining. However, there is some choppiness to the video, particularly when scrolling (vertically or horizontally).

[nes.og]

@NoAffinity:

Have you tried this one?

https://www.amazon.com/dp/B07121Y1Z3/re ... UTF8&psc=1

If so then how does it compare to the other ones?

Thanks

[NoAffinity]

@NoAffinity:

Have you tried this one?

https://www.amazon.com/dp/B07121Y1Z3/re ... UTF8&psc=1

If so then how does it compare to the other ones?

Thanks

Not that specific one, but I have 2 that are identical to it. The consensus so far is all of the converters in that form factor are pretty much the same.

Noisy image, reduced brightness, washed-out colors, some softening to the image. No noticeable lag is the one good thing that can be said about them.

There are slightly cheaper versions of the same thing. For the money, it gets the job done, but with some trade-offs in image quality.

Unless there's something about this particular unit that makes is significantly different from the other identical models from various chinese manufacturer's, I would expect all of the above will be true for this one as well.

[nes.og]

Good to know, I’ll have to check out that Monoprice unit.

Do you have a recommendation for HDMI to VGA?

[NoAffinity]

Good to know, I’ll have to check out that Monoprice unit.

Do you have a recommendation for HDMI to VGA?

https://www.amazon.com/dp/B082VYRXBJ?re ... b_ap_share

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[TABYDACAT]

In an earlier post in this forum, somebody mentioned wanting the ability to use physical buttons to select/load their custom presets. I've been messing with this idea and I think I finally have something that's use-able for the most part. I haven't seen anyone taking on this request (please tell me if I'm wrong lol) so wanted to give it a go.

Two buttons are utilized, one that selects the preset slot and another that actually loads the preset. OLED functionality is also implemented allowing the user to see the preset being selected/loaded. Along with this it shows a few lines of basic info that is coming from the GBS 8200 like input activity and resolution.

This is purely a test/beta/experiment to see if this is actually useful and maybe perhaps be an alternative to how people use their GBS 8200s! It would be cool if others out there would like to give this a try and see what they think whether it's aesthetically or code based suggestions.

NOTE:
* A PS1, PS2, and Dreamcast were mainly used to get SCART, VGA, and Component fed through the GBS 8200. All seemed to work with this edit.
* The OLED stuff was made with a 128x64 OLED screen to have a merge of simplicity, cost and form factor. I used an OLED with a Yellow/Blue color configuration so the edits are made with that in mind so some stuff may look off putting if a single color configuration is used.
* This is just an initial version, more tweaks will be done (I already have a to-do list lol)
* The hardware requirement for this is pretty simple: two toggle buttons and an I2C 128x64 OLED

[root991]

Hello, I have a GBS HD 9800 board v5.0 and it works perfectly, before then I decided to remove an RGB potentiometer and bridge them. But after bridging - I found that the RED color was lost. I re-solder bridge lines and after that RED and GREEN signals were lost. At this moment I'm very confused because I can find any similar issue from anyone. Can somebody point me in the direction of a further investigation?

I had a similar problem when I was a bit rough in removing with a side cutter some leftover piece of pin after desoldering the others cleanly. Long story short, the side cutter created a scratch in the surface of the board near one of the through holes, which ended up having a small trace of solder leading up to the bridge - which grounded it.

As one of the pins of each potentiometer leads to ground, it's worth checking even if you already tested for continuity.

Another idea is to check if any small fragment of solder or potentiometer pin ended up attaching to a resistor in the area. This happened to me with my other board, but was fixed before testing.

IMO that area of the PCB is sensitive and with the entire GBS board being a bit brittle, I'll probably bridge the potentiometers on the bottom side - without removing them - if I'm building another GBS variant at some point.

Yeah, I have already found that there was a short at the RED color potentiometer(battery in my tester died so i was cannot check the bridge after the soldering) But now, I have already fixed that. Thanks for a support!

[AndehX]

Hey guys. So I just built a new GBS control scaler using a GBS8220. Did all the hardware mods (added caps etc)
720p looks great, but 1080p has alot of wavy interference in it. Any ideas what is causing this? I've tried playing with SDRAM speed settings etc but nothing seems to affect it.