GBS 8200/8220 CFW Project

[Jiimboo]

Hi!

I am assembling the GBS with a SCART input, I've a doubt about that...

If you put the 100 ohm resistor:



You need (or it's recommended) to make the LM1881 circuit?

It's additional or an alternative?

Thank you for all the work, improves and replies!

[NoAffinity]

If you plan on inputting vga then you want to be able to remove the 100 ohm resistor. If that is the same sync connection as the 5-pin connector and you wont be inputting vga then it should be fine.

You dont need the lm1881 circuit at all unless you'll be trying to downscale vga input.

[Jiimboo]

If you plan on inputting vga then you want to be able to remove the 100 ohm resistor. If that is the same sync connection as the 5-pin connector and you wont be inputting vga then it should be fine.

You dont need the lm1881 circuit at all unless you'll be trying to downscale vga input.

Hi, thanks for the reply.

I only want to connect scart-rgb

[stj]

i just got back to this after a long time and i'm having a problem,
i'm using the same hardware that worked last year - just the latest software build is all i changed.
the scaller works - it's converting the signal fine.
the issue is the wifi control,
the mobile browser is just displaying a blue GBS-C splash screen with some red icon flashing in the upper right corner.
what is the flashing red bit trying to tell me?
why isnt the menu working?

[Kez]

It means you've lost connection to the device. When you connect to the GBS-C, it loads the page into your web browser but also maintains a connection to the device. If you lose the connection, the page will still be in your browser but you can no longer send commands to the GBS-C.

If your signal was okay before, it's strange that you're now having connection problems. Is the GBS-C in the same location/orientation as before? And you are displaying the same resolutions? I have found my connection can be a bit flaky when outputting 1080p vs a lower resolution.

[stj]

interesting.
the phone is about 2 feet from the module - literally sitting on the same desk
but i was pushing it hard.
i had a ps3 running a hdmi>vga adapter and then using the gbs to re-time the signal and feed a hi-res vga monitor that doesnnt like 50/60Hz frames.

is the issue more likely to be a high input resolution or a high output one?

[stj]

well,
i found the issue.

the code is not W3C compliant and gives different results with different mobile browsers.
not having the patience to install 10 browsers or whatever to do tests, i'll just shelve the project for now.
it wont work on browsers based on apple "webkit" btw - thats a lot of browsers including most if not all games consoles!

[RMGA]

Help needed!
I recently got a GBS 8200, i modded it (WIFI Chip, Clock Gen, caps connected in paralel, r34 resistor replaced with 75ohm and others). I have tested all of my consoles and all of them work, but my PAL mega drive 2 with 32X, Mega CD and Scart cable CSYNC, drops sync randomly. On the scart female connector on my GBS C i've put a 680ohm resistor, and it helps a bit but still unstable...

Here is a video of the problem:

https://youtu.be/7yIltteHbEY

Thanks in advance!

[NoAffinity]

Confirming - you arent doing the 100 ohm sync to ground resistor and r34 replacement? It should be one or the other.

Below is proper cable setup for a md2. Was your sync line completley non attenuated prior to adding the 680 oh resistor? And you've confirmed csync from the console to the correct pin at the scart end?

Spoiler

[RMGA]

Below is proper cable setup for a md2. Was your sync line completley non attenuated prior to adding the 680 oh resistor? And you've confirmed csync from the console to the correct pin at the scart end?

Spoiler

Yes, CSYNC is on pin 5 (from the mega drive connector). Strangely mine didn't have a 470ohm resistor and 220uf cap on CSYNC, i will add those right now and see if it works

[RMGA]

Ok so i added a 470ohm and 220uf 10v capacutor on the CSYNC line on the mega drive and it still doesn't work. But here's the weird part, if i put a 100ohm resistor on the GBS sync and ground it is more stable but still drops sync, but if i remove it it glitches out, even if i replaced the r34 resistor with a 75ohm one. I'm out of ideas on what i could try...

[maxtherabbit]

well,
i found the issue.

the code is not W3C compliant and gives different results with different mobile browsers.
not having the patience to install 10 browsers or whatever to do tests, i'll just shelve the project for now.
it wont work on browsers based on apple "webkit" btw - thats a lot of browsers including most if not all games consoles!

You can try reverting to the older version of the project that used a completely different web interface. I don't recall exactly when that was changed but I'm fairly sure no actual scaling code was altered.

[stj]

i actually took a final look at it,

i found a browser that works really well, called "Lightning"
you can download it from the F-Droid store - for Android obviously.

[NoAffinity]

Ok so i added a 470ohm and 220uf 10v capacutor on the CSYNC line on the mega drive and it still doesn't work. But here's the weird part, if i put a 100ohm resistor on the GBS sync and ground it is more stable but still drops sync, but if i remove it it glitches out, even if i replaced the r34 resistor with a 75ohm one. I'm out of ideas on what i could try...

@RMGA - I pulled out my trusty GBS-8220. Well, after melting the EPS due to not paying attention and using an incorrect power supply on it, and replacing the EPS, I tested my US Genesis model 2/Sega CD mdoel 2/32x combo w/ 3BP. I thought I remembered having similar sync drop issues with my genesis (don't remember if I had the 32x and/or CD at that point), so wanted to test. My cable is wired for csync and from retrogamingcable uk:

Spoiler

https://www.retrogamingcables.co.uk/seg ... le-tv-lead

Currently, only the 480p profile works reliably with my setup. All other upscale profiles produce a jumpy image.

I didn't test downscale or pass-thru and didn't mess with any settings other than some of the Picture Control positional settings.

I don't have any intentions of trying to troubleshoot it on my end, just thought the results and data points might be useful.

:edit: Also, I'm using a firmware build older than the current one on the github. The current one wouldn't work for me. I didn't spend too much time on it tho. I flashed a version that I downloaded on 12/27/2019, and is the final version to the best of my knowledge, minus some UI upgrades, but functionally should be the same as the current build.

[VEGETA]

Hello

I searched and found the chip does not support scanlines effect by itself, and saw the code but couldn't understand how it is done.

can you kindly explain to me how you did it in steps?

thanks

[orange808]

Hello

I searched and found the chip does not support scanlines effect by itself, and saw the code but couldn't understand how it is done.

can you kindly explain to me how you did it in steps?

thanks

Rama explains the effect is a convenient hack of the Trueview5725 deinterlacing behavior when one field is left blank. This chip doesn't officially support scanlines, but it can produce them under some limited conditions.

Edit: here's the link where Rama chimed in with an explanation:
https://github.com/ramapcsx2/gbs-control/issues/68

[VEGETA]

Hello

I searched and found the chip does not support scanlines effect by itself, and saw the code but couldn't understand how it is done.

can you kindly explain to me how you did it in steps?

thanks

Rama explains the effect is a convenient hack of the Trueview5725 deinterlacing behavior when one field is left blank. This chip doesn't officially support scanlines, but it can produce them under some limited conditions.

Edit: here's the link where Rama chimed in with an explanation:
https://github.com/ramapcsx2/gbs-control/issues/68

thanks for this.

i still didn't understand fully, like the scanlines code line by line how does it do the hack...?

I wanted to ask if there is a way much simpler way of overlaying a .bmp file which contains the black lines and empty transparent lines.... on top of the video. can it be done?

[orange808]

thanks for this.

i still didn't understand fully, like the scanlines code line by line how does it do the hack...?

I wanted to ask if there is a way much simpler way of overlaying a .bmp file which contains the black lines and empty transparent lines.... on top of the video. can it be done?

AFAIK, all the ESP8266 does is "hijack" control of the Trueview5725 from the circuitry that ships with the Gonbes boards. There's a few additional hardware modifications that add enhancements, but it's still a Gonbes board and a TV5725, correct? I don't know if the TV5725 supports feeding an "overlay" image beyond its built in OSD capabilities. Maybe someone else can answer that. Looking over the documentation, the TV5725 has very limited OSD support and that's restricted to a set of predefined onboard icons and maybe some text.

[RMGA]

Currently, only the 480p profile works reliably with my setup. All other upscale profiles produce a jumpy image.

I didn't test downscale or pass-thru and didn't mess with any settings other than some of the Picture Control positional settings.

I don't have any intentions of trying to troubleshoot it on my end, just thought the results and data points might be useful.

:edit: Also, I'm using a firmware build older than the current one on the github. The current one wouldn't work for me. I didn't spend too much time on it tho. I flashed a version that I downloaded on 12/27/2019, and is the final version to the best of my knowledge, minus some UI upgrades, but functionally should be the same as the current build.

I'm using the latest firmware. I can't seem to find the firmware that you're using. May you upload your firmware on wetransfer or google drive so i can test it on my end?

[NoAffinity]

Currently, only the 480p profile works reliably with my setup. All other upscale profiles produce a jumpy image.

I didn't test downscale or pass-thru and didn't mess with any settings other than some of the Picture Control positional settings.

I don't have any intentions of trying to troubleshoot it on my end, just thought the results and data points might be useful.

:edit: Also, I'm using a firmware build older than the current one on the github. The current one wouldn't work for me. I didn't spend too much time on it tho. I flashed a version that I downloaded on 12/27/2019, and is the final version to the best of my knowledge, minus some UI upgrades, but functionally should be the same as the current build.

I'm using the latest firmware. I can't seem to find the firmware that you're using. May you upload your firmware on wetransfer or google drive so i can test it on my end?

Here you go: https://drive.google.com/drive/folders/ ... sp=sharing

[RMGA]

Currently, only the 480p profile works reliably with my setup. All other upscale profiles produce a jumpy image.

I didn't test downscale or pass-thru and didn't mess with any settings other than some of the Picture Control positional settings.

I don't have any intentions of trying to troubleshoot it on my end, just thought the results and data points might be useful.

:edit: Also, I'm using a firmware build older than the current one on the github. The current one wouldn't work for me. I didn't spend too much time on it tho. I flashed a version that I downloaded on 12/27/2019, and is the final version to the best of my knowledge, minus some UI upgrades, but functionally should be the same as the current build.

I'm using the latest firmware. I can't seem to find the firmware that you're using. May you upload your firmware on wetransfer or google drive so i can test it on my end?

Here you go: https://drive.google.com/drive/folders/ ... sp=sharing

Thanks man, i appreciate it

[RMGA]

Hello again, i recently installed an oled screen and it worked 3 days without issues. Today i wanted to play something and the oled screen for gbs c was working fine until the image in the game started to corrupt and i got a "gbs board not responding", i didn't touch anything and it stopped working. I installed the 2019 firmwarw a person on this forum gave to me and the board fumctioned again, without the oled screen (because the fw was too old for it). The latest firmware has a lot of issues and things stop working by themselves, maybe i'm doing something wrong but that's not the case because 3 days ago it worked perfectly fine.... and i want the oled screen because it shows the frequency in real time and it helps me improve this device.

[KnightNZ]

i just got back to this after a long time and i'm having a problem,
i'm using the same hardware that worked last year - just the latest software build is all i changed.
the scaller works - it's converting the signal fine.
the issue is the wifi control,
the mobile browser is just displaying a blue GBS-C splash screen with some red icon flashing in the upper right corner.
what is the flashing red bit trying to tell me?
why isnt the menu working?

The firmware I had from a year or so back was fine, the current one seems to have major UI stability issues - either something in the web server or something in the networking seems to have become a lot less stable than it was, I'd rather not revert too far as one of the changes from earlier this year did sort out some issues I was having.

[AaronSR]

My GBS-C seems to have developed a slight fault (its a pre built one from amazon, the small orange "ODV-GBS-C"): https://www.amazon.co.uk/Mcbazel-ODV-GB ... B0BMDT9Z9L

I bought this over a year ago and its worked great, the problem is that, I'm getting a slight yellow tint on the output, despite the color correction knobs being fully turned to off. I think its after I've been using it a short while and it warms up, the tint appears. I think its coming from the Blue knob because when I put pressure on that one specifically, it corrects itself but eventually comes back. I'm wondering if its safe to somehow disconnect or disable the knobs entirely? Cutting the traces on the board maybe? Or will that just permanently kill the output? I can take a picture of the board if need be. Thanks.

https://media.discordapp.net/attachment ... 00/1-2.png
https://media.discordapp.net/attachment ... 78/2-2.png

[Das Muel]

Just my two cents about the Mcbazel ODV unit if anyone’s interested. It has some serious flaws as a standalone unit but when using it in conjunction with a secondary scaler (an Extron 300a in my case) it does a really nice job.
Firstly, when using the HDMI output of the Mcbazel, something is not right with the colours to my eye. They look compressed or at least processed in a non pleasing way. Fortunately the analogue VGA output on the other hand looks lovely, so I feed that into my secondary scaler instead.
Similarly the audio via HDMI sounds noticeably compressed to my ear, and the Mcbazel's analog output is missing the left channel altogether on my unit, so I actually break out the audio from my scart switcher and feed that directly to the Extron instead.
Thirdly it suffers with screen tearing in almost every output mode, EXCEPT for the basic linedouble, 480p mode. Fortunately my Extron does a great job with 480p, so ultimately I get a very pleasing image. 480i from a Saturn or PS2 in particular is a bit of a highlight.
I also had little rgb line dropouts from time to time on the SCART input, wherin the output would take on a strong blue tint at times, but a quick reflow with a soldering iron sorted that problem out. Build quality is a little shonky.
The image, when upscaled with an Extron or similar is very nice, but the Retrotink 5X is the better option by every conceivable metric really, barring the deinterlacing perhaps. This combo is certainly comparable though, and quite a bit cheaper of obviously. I'm pretty happy with it as things stand although I'm looking forward to the OSSC Pro.

[AaronSR]

So for my setup I'm mostly only using DB15 cables from retro-access fed into the VGA port and then audio going into the component stereo jacks, I dont seem to have that problem with the left channel but perhaps its a scart input problem? I can check with my PS1 scart (this is the only scart cable in my setup anymore, I do plan to replace it with a PS1 DB15 cable when retro-access is up and running again). What I have noticed though is the audio is "loud", I know its a simple case of "turning it down" on my TV but I dont know if its peaking to the point of "losing quality".

Also yeah, I get tearing with everything too, more especially widescreen content set to 720p, if I set my OG Xbox to 480p widescreen its especially bad, even if I set it to passthrough mode. I haven't tried the VGA output, my capture card at least has VGA input but ultimately I'm probably going to invest in a retrotink eventually, one of the main reasons I went with GBS was the VGA input is extremely convenient for my setup, with the 5X I can only find like one adapter that will convert it to scart, I really wish it had a VGA port on it.

[Das Muel]

I had a blue tint on the output with mine that kind of came and went. It was definitely the Mcbazel and not the scart lead or the console itself as the output was fine with everything else I used. I decided to quickly reflow the solder points on the underside of the pcb of the Mcbazel around the scart input. I also did the solder points for the pots. That worked for me and the output now looks great and is stable too. Perhaps that's worth a shot? (On the VGA input in your case I guess)

[AaronSR]

Yeah that sounds like the same problem I'm having except for me its yellow tint instead of blue, most likely the pots. I personally have never needed to use them and kind of wish they were omitted.

[casuais_play]

I know the brand RetroScaler isn't something id recommend using (older unit) but what about this new? GBS-C Variant?

Anyone has tested it and does it hold up to the ususal GBS-C Setups?




the slick PCB looks nice it has also a glock gen inside, think it's alswo firmware upgradable from the usual GBS-Cs right?!

I've read that for example the ODV Variants should be avoided because of image ringing effects but what about the quality of this one? its very inexpensive aswell

I have this model with PCB version 1.6. I'm having instability problems with the Wii. The image jumps in a frame at random times. This only happens with the Wii.

[Bassa-Bassa]

What else have you tried aside from the Wii and which outputs?