GBS 8200/8220 CFW Project

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NoAffinity
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Re: GBS 8200/8220 CFW Project

Post by NoAffinity »

Syntax wrote:Did you remove the ceramic cap near the LM1117 1.3v LDO?
Is that the one that gets replaced with a tantalum capacitor? If so, yes I replaced it and it did nothing.

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rama
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Re: GBS 8200/8220 CFW Project

Post by rama »

Ah yeah, that is auto offset not working correctly.
I've disabled it again, until I find out why it fails on some boards.

It is a great feature in theory. It's supposed to balance the color components to the same offset from 0.
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NoAffinity
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Re: GBS 8200/8220 CFW Project

Post by NoAffinity »

Much better, methinks. I did auto gain on the GBS. On the OSSC, I zeroed out the individual color gains, set pre-ADC gain to '8' and adjusted individual offsets. There's still a little noise if I get up close to the screen, but none noticeable at normal playing/viewing distance.

https://youtu.be/iG5MFeoEfBc

I also rechecked all my mods, and they are all up-to-date, referencing the github mod list. C11 is absent.

Oh, and I'm going to grab a 19" viewsonic CRT PC monitor later this morning, model PS790. Can't wait to see the GBS outputting to that bad boy.
rama
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Re: GBS 8200/8220 CFW Project

Post by rama »

These are very good results, always considering that the sample rate and all the following processing isn't even source clock aligned.
With lots more effort it can be sharper of course :p

I see no noise in the video.
Noise strongly depends on the preset used and the particular GBS board.
The boards are generally okay but I have a real stinker yellow button here, too :p
rama
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Re: GBS 8200/8220 CFW Project

Post by rama »

AndehX:
I ran into your issue, I believe.
There is a possibility that the GBS board power check affects I2C, which is a pretty bad bug!
The failure causes gbscontrol to read back all the required bits for an active RGBHV connection, hence the problem.

I'm working on a fix :)
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AndehX
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Re: GBS 8200/8220 CFW Project

Post by AndehX »

awesome! I'm assuming it only affects certain boards?
rama
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Re: GBS 8200/8220 CFW Project

Post by rama »

I guess I'm just discovering that open drain outputs with external pull-ups can't be read?
It appeared to work fine, plus I there is some sample code that shows this, so idk.

I'm now assuming I need to change the pins to inputs, read the value, change back to open drain output.
This makes it a little more tricky but so far it looks good :)
Eduardoml
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Re: GBS 8200/8220 CFW Project

Post by Eduardoml »

Hi, I trying use the gbs-control CFW with a mid res 512x400 arcade game as source (Jamma ega/cga connector ) in a modern LCD (VGA), but I had no luck, no video. :|
I using a Wemos D1 and everything went fine in arduino ide, compiling and uploading without any problem, I using the GBS VIN and GND to power the Wemos D1 and a 5v 1.2 amp power supply in the GBS. In the bellow of the gbscontrol.local page the console says:
*!**!**!**!*<reset>
Scanning inputs for sources...
Activity detected, input:Component
*!***
Thats wrong? I have nothing connected in the Component input, only in the ega/cga input, do I have to change something in the code or in the configuration to make it work? Or just don't work with my resolution or my LCD? Please if someone can help I will be very grateful. :)
rama
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Re: GBS 8200/8220 CFW Project

Post by rama »

Hey,

I need more details to help you with this.

What type of sync signal are you using? The RGB port supports combined sync on the "S" pin and separate H+V.
Please post a complete log of gbscontrol starting up and then failing to detect the source correctly.
You will need to connect your pc with Arduino IDE for this, then use the Serial Monitor, so you get the complete logs.
Ryoandr
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Re: GBS 8200/8220 CFW Project

Post by Ryoandr »

I have something wierd going on with 2 boards of the same model with latest release.
On my 1st, I get picture jumping up and down
on the 2nd I have the same up down problem, plus picture gets a blue tint on bright scenes.
Sometimes I get stutter too, tried various presets and options such as frametime lock, to no avail.

The 1st is the test board I did a while ago with a LoLin, has 750pf on C33 and C35 and the 100R.
The 2nd board has the same LoLin, with 1nf on C33 and C35 and the 100R too.
This happens with an MVS with a Parsec supergun with an MD2 cable. I also tried a 60hz switched euro MD with the same cable and have the same kind of problems. The cable is wired for composite video as sync, the Parsec generates composite video, and the MD is wired for csync with a 470R inside.

Also, something I noticed, the 1st GBS has a 1K R34 sync termination, while the 2nd has a 2.2K R34, which brings measured termination closer to 91 ohms.

I have a 3rd board that I can test for that blue tint, bought at the same time as the 2nd.
rama
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Re: GBS 8200/8220 CFW Project

Post by rama »

Ryoandr:

I found more details and hidden register bits regarding the SOG clamper.
Using these new findings requires a sync processing rewrite, which I'm almost done with.

Once everything works again, there'll be some changes.
Example: I think we can stop changing the SOG capacitors! :)

But regarding your troubles now, I also noticed that Mega Drives with Composite Video sync are unstable.
The problems can be corrected by tuning the SOG slicer comparator level (using the command 'wsog x', where x between 1 and 9).
Regardless of that, Mega Drive CSync operation with the ~470 Ohm resistor is always borderline. It's just not a robust mod to begin with.
It should work if the required attenuation is done: 470 Ohm inline resistor, ~75 Ohm termination but there is little wiggle room.

The new sync code will take care of all these issues. It'll increase the margins a lot :)
Ryoandr
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Re: GBS 8200/8220 CFW Project

Post by Ryoandr »

ok so the blue tint on bright scene is confirmed to be a faulty GBS, doesn't appear on the 3rd board.
up/down bobbing is still present.

Rama, I *think* the MD I use has a capacitor and a resistor, going from VDP sync (same as DIN sync pin) to an MD2 minidin socket (this machine is a frankenstein of all sorts). I know it's not recommended to use MD sync directly, or with only a resistor.
rama
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Re: GBS 8200/8220 CFW Project

Post by rama »

I'd have to see that blue tint happening to say anything about it. If sync is problematic, then the colors are wrong as well.

The capacitor on sync may help or it may not. I guess it won't make a difference with the GBS.
Ryoandr
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Re: GBS 8200/8220 CFW Project

Post by Ryoandr »

Rama here is a quick vid, you can see the blue tint occuring, and this is not an exposure problem from the camera.
https://streamable.com/t0zlh
Eduardoml
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Re: GBS 8200/8220 CFW Project

Post by Eduardoml »

rama wrote:Hey,

I need more details to help you with this.

What type of sync signal are you using? The RGB port supports combined sync on the "S" pin and separate H+V.
Please post a complete log of gbscontrol starting up and then failing to detect the source correctly.
You will need to connect your pc with Arduino IDE for this, then use the Serial Monitor, so you get the complete logs.
I soldered the Debug Pin, VIN, GND, SDA and SCL in the GBS and worked great in component in my moded Snes and moded Genesis and I got fantastic results, the image is great, but in my arcade board still not working, probably because of the game is for 25 inch medium resolution arcade monitor the resolution is 512x400 and speed 24Khz, the log in the Serial Monitor says:
userprefs.txt opened
loading from preset slot 5: /preset_ntsc.5
post preset done (preset id: 1)(custom)
.Base 1796 Best:1801 Fieldrate 59.857
SOG Lvl:11
..*!**!**!**!**!*<reset>
Scanning inputs for sources ...
Activity detected, input:RGBS/HV
lost..
Activity detected, input:RGBS/HV
lost..
Activity detected, input:RGBS/HV
lost..
Activity detected, input:RGBS/HV
lost..
Activity detected, input:RGBS/HV
lost..
Activity detected, input:RGBS/HV
lost..
Activity detected, input:RGBS/HV
lost..
Activity detected, input:RGBS/HV
lost..
Activity detected, input:RGBS/HV
lost..
Activity detected, input:RGBS/HV
lost..
Activity detected, input:RGBS/HV
lost..
And I got no video, messing with the Development options (SyncWatcher) I get a scrambled image like this:

Image

and the Serial Monitor says:
sync watcher off
loading from preset slot 5:no preset file for this source
post preset done (preset id:1)
SOG Lvl: 11
Unknown timing!
Unknown timing!
Activity detected, input:RGBS/HV
lost..
Unknown timing!
Unknown timing!
Activity detected, input:RGBS/HV
lost..
Unknown timing!
Unknown timing!
Activity detected, input:RGBS/HV
lost..
Unknown timing!
Unknown timing!
I can see that the firmware is struggling to get the resolution and speed right, but it's not working, would there be something I could do to fix and make it work on this arcade board?
Thank you for your help.
rama
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Re: GBS 8200/8220 CFW Project

Post by rama »

Eduardoml:
So this looks like CSync or Sync on Composite, not separate H/V.
The problem then is indeed the unknown video mode.

So I know why it fails, but right now there nothing I can do from here.
I would need such a board / sync source, and implement the video mode.
As long as the vertical period is indeed around 60Hz, there won't be any big issues.
The GBS can handle it just fine, but it needs to have software support for it.

Note:
Even if you provided H+V Sync, then gbscontrol would bypass the signal fine, but the display still couldn't handle it.
So it has to be software supported upscaling mode.

Ryoandr:
Well, I can definitely see the stutter from the sync dropouts.
Wait a little for the sync rewrite, then try that. It might fix the color issues :)
rama
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Re: GBS 8200/8220 CFW Project

Post by rama »

I just updated the development branch with the new sync processing.
https://github.com/ramapcsx2/gbs-contro ... evelopment

The most important change for users is that the SOG capacitors can (and should) stay at the default 100nF now.
I'm aware that reverting this hardware mod is difficult, because the solder area isn't as clean as with a stock board.
The change is great for new users and stock boards, which are the vast majority. I hope you guys understand.

If you want to undo the mod, use 2 x 100nF 0605 capacitors (anything between 39nF and 100nF works well).
For removing the 1nF caps, I would recommend to add solder to both sides of the part, so you can more easily heat both sides at the same time.
Once removed, check for bridges (fix them with wick or solder sucker if needed) and clean up the area.
If you have 0605 parts, installing them should be easy now.

Sync processing is very different now and there are a few benefits beside just "being stable".
With the new SOG clamp, it became possible to use the SOG separator better.
I see better behaviour with Mega Drives, with H-PLL lock when using Composite Video Sync, etc.

Hope to get some test results from you guys :)
Eduardoml
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Re: GBS 8200/8220 CFW Project

Post by Eduardoml »

rama wrote:Eduardoml:
So this looks like CSync or Sync on Composite, not separate H/V.
The problem then is indeed the unknown video mode.

So I know why it fails, but right now there nothing I can do from here.
I would need such a board / sync source, and implement the video mode.
As long as the vertical period is indeed around 60Hz, there won't be any big issues.
The GBS can handle it just fine, but it needs to have software support for it.

Note:
Even if you provided H+V Sync, then gbscontrol would bypass the signal fine, but the display still couldn't handle it.
So it has to be software supported upscaling mode.
Yes the service manual of the arcade board says it is CSync, the V and H are combined in the same cable, the CGA conector has Redgun, Greengun, Bluegun, GNDgun and Video Sync (CSync). The original Firmware works without problem, maybe if I send the parameters of the signal the video mode could be implemented.
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maxtherabbit
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Re: GBS 8200/8220 CFW Project

Post by maxtherabbit »

rama wrote:I just updated the development branch with the new sync processing.
https://github.com/ramapcsx2/gbs-contro ... evelopment

The most important change for users is that the SOG capacitors can (and should) stay at the default 100nF now.
I'm aware that reverting this hardware mod is difficult, because the solder area isn't as clean as with a stock board.
The change is great for new users and stock boards, which are the vast majority. I hope you guys understand.

If you want to undo the mod, use 2 x 100nF 0605 capacitors (anything between 39nF and 100nF works well).
For removing the 1nF caps, I would recommend to add solder to both sides of the part, so you can more easily heat both sides at the same time.
Once removed, check for bridges (fix them with wick or solder sucker if needed) and clean up the area.
If you have 0605 parts, installing them should be easy now.

Sync processing is very different now and there are a few benefits beside just "being stable".
With the new SOG clamp, it became possible to use the SOG separator better.
I see better behaviour with Mega Drives, with H-PLL lock when using Composite Video Sync, etc.

Hope to get some test results from you guys :)
that's badass - I had been putting off modding mine since those caps looked like a pain in the dick to replace :mrgreen:
Ryoandr
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Re: GBS 8200/8220 CFW Project

Post by Ryoandr »

Tried latest dev code.
Good news is this makes it work with the GBS with blue tint. I don't know why that board is behaving like this but oh well, no more blue tint.

Still has some stutter sometimes at console start, but a preset change is usualy enough to resync.
On some resolutions (1280x1024, 1920x1080), the vertical scaling isn't integer resulting in uneven scanlines generation. Line filter helps a bit but not totally depending on source and type of game. Can be fixed with some scaling. Just a minor thing really.
rama
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Re: GBS 8200/8220 CFW Project

Post by rama »

Well caught with the vertical scaling ;p

I decided to fix the worst aspect ratio issues, but at the cost of a perfect scanline look.
Some day I'll investigate what further options we have regarding scanlines.
The line filter is crucial for now though.
I think other scalers also prefer aspect ratio over integer scaling?

It's good that the CV source now works. This is a major improvement over what was possible before.
I think I still need to work a little more on dialing in a fitting SOG slicer level but yeah,
at least the SOG slicer can now work with much more of the sync pulse :)
Ryoandr
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Re: GBS 8200/8220 CFW Project

Post by Ryoandr »

Any chance of having adjustable gamma boost when scanlines are enabled ? I always find it a tiny bit too bright.
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AndehX
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Re: GBS 8200/8220 CFW Project

Post by AndehX »

man, now im gonna have to undo that mod? Balls xD

Oh well, such is the life of a beta tester :D
rama
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Re: GBS 8200/8220 CFW Project

Post by rama »

Ryoandr wrote:Any chance of having adjustable gamma boost when scanlines are enabled ? I always find it a tiny bit too bright.
Possibly, yes. I don't have the time to investigate that now but if you want, these 3 registers are currently used for tuning:

Code: Select all

GBS::VDS_Y_GAIN::write(GBS::VDS_Y_GAIN::read() + 0x30); // 3_35 more luma gain
GBS::MADPT_VIIR_COEF::write(0x14); // set up VIIR filter 2_27
GBS::MADPT_Y_MI_OFFSET::write(0x28); // 2_0b offset (mixing factor here)
AndehX:
It might work with the 1nF caps but if you get issues, you know what to do :p
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NoAffinity
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Re: GBS 8200/8220 CFW Project

Post by NoAffinity »

Hey Rama the new developments are looking great. sadly I have so little free time due to a new job, I'm sticking with a build that's 3 or 4 updates old so I dont have to undo any mods. :/

Nonetheless I managed to score a couple perfectly working 17" PC crt's in a local auction (and a 20" nec diamondtron....but it's not working :'(

But, I gotta say that driving an analog PC monitor with gbs cfw is a whole new level of awesome. Keep up the good work!
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retromaniak
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Re: GBS 8200/8220 CFW Project

Post by retromaniak »

Hi, I wanted to ask if there would be an option to disable de-interlacing. I am referring here primarily to the Playstation Portable console which, on the component cable, transmits the image progressively, and so the controller tries to remove the interlace that does not exist.
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NoAffinity
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Re: GBS 8200/8220 CFW Project

Post by NoAffinity »

Is there something unique about the ps portable signal? Gbs with cfw has been tested with many flavors of 240p, 480p and 480i and it has never mishandled any of them. What else is in your chain?

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AndehX
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Re: GBS 8200/8220 CFW Project

Post by AndehX »

retromaniak wrote:Hi, I wanted to ask if there would be an option to disable de-interlacing. I am referring here primarily to the Playstation Portable console which, on the component cable, transmits the image progressively, and so the controller tries to remove the interlace that does not exist.
If you set the deinterlacer to bob, I believe that turns it off?
Ryoandr
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Re: GBS 8200/8220 CFW Project

Post by Ryoandr »

Rama, about the scanlines brightness boost, having tested it on an LCD, it's actually near perfect on that kind of display. It's on VGA CRTs that the boost is a bit too bright, some light skin tones get really overbright.

Tried my best to capture it.
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rgn11
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Re: GBS 8200/8220 CFW Project

Post by rgn11 »

Greatly appreciate if anyone could answer some of these questions I've had:

1) I believe I already have a sync strike lying around. Does this mean I don't need the 100ohm resistor to sync and ground since I'll be using the VGA output from the sync strike to the VGA input on the GBS?

2) I have the GBS board revision with one VGA output and black buttons (as an aside, it looks exactly like the 1 output 8200 models to me, but mine is branded the HD 9800 for some reason); so if I don't need the resistor, I assume the only applicable mods are the power supply bypass capacitors and C11 removal? Is the ferrite bead preferable to removal of C11?

3) Also, for those that own both the OSSC/GBS, does anyone have any comparison comments or images; I bought the GBS years ago as a budget option before the OSSC was around, and I'm wondering about the comparison.

4) Lastly, I can seem to find many images of people's completed wiring; does anyone have a closeup of a fully modded board?

Thanks for any answers.
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