GBS 8200/8220 CFW Project

[rama]

fluxcore:
I wouldn't worry about getting everything together first.
The GBS will work with the default capacitors, but sync over Composite Video may have some dropouts.
It's easily fixed at any later point by changing those caps.
The best size for them is probably 0603, but I used 0805 without too much trouble.

You'll want to limit your sources to regular TV level stuff, because I heard that some arcade boards push a way too high RGB signal.
Once you have the adapter that normalizes RGB, I expect every board to work.
I did a lot of tests with "weird" sources, using my custom clocked SNES. The software can cope with pretty drastic timings, such as 55Hz or 68Hz.
At that point, only your display has got to accept it, and if it's VGA, it will for sure

Going back to OWF requires removal of the jumper and disabling the ESP8266.
The 8266 never outputs a voltage on any of the connected pins, but it does pull the I2C lines low.
When the original MCU and the ESP8266 both pull the line low, then the scaler will simply not work (but no damage be done to anything).
Removal of the ESP8266 I2C wires prevents all possible issues.

[NoAffinity]

Good call, rama! I completely forgot about removing the RGB pots. Done and auto adjusted. Looking much better, methinks.

Spoiler

[keremimo]

It has been a while since I have actively followed the project so is there any new necessary hardware modifications? Like removing resistors etc.

Getting a new gbs board since mine got fried by itself (probably because I inputted TTL sync off my own lm1881 setup, since fixed using a resistor)

What would be a checklist? Can I directly connect a 12v power supply?

[Syntax]

This is overkill but its what I do now.

Remove C11
Put 10uf Tantalum capacitor on LDO input 22uf Tantalum capacitor on LDO output
7x 22uf X7 ceramic decoupling caps fit under the stock electrolytic caps (C65 C66 C3 C4 C5 C6 C7)
2x1n caps on both sync input lines. (Replace C33 C35)
2x1000r resistors removed, one of them is replaced with a 75R to fix termination.(remove R32 replace R34)
Pots removed to fix color levels.
L1 L2 L3 removed and 220R@100 ferrite beads installed.
Ferrite bead on charge pump.(replace R58)
Charge pump decoupled with 100n cap.(Between R59 and R58)

[NoAffinity]

What would be a checklist? Can I directly connect a 12v power supply?

Yes. I'm using a 12V 1A power supply on mine as of today, and it's working, no problems.

[fluxcore]

Is

Code: Select all

 no sync found
low power
<reset>

coming from the NodeMCU itself, or a pass-through from the GBS? I can get the setup to lock on to 'nothing' (no input) if I'm powering the NodeMCU from USB, but having no joy through either the 3.3V off P5 nor the source 5V input (using a "2.5A" 5V adapter yoinked from an DSL router). I'm guessing the adapter can't handle the jandal. Multimeter shows a steady 5.1V coming through though.

[NoAffinity]

Is

Code: Select all

 no sync found
low power
<reset>

coming from the NodeMCU itself, or a pass-through from the GBS? I can get the setup to lock on to 'nothing' (no input) if I'm powering the NodeMCU from USB, but having no joy through either the 3.3V off P5 nor the source 5V input (using a "2.5A" 5V adapter yoinked from an DSL router). I'm guessing the adapter can't handle the jandal. Multimeter shows a steady 5.1V coming through though.

So, you have 3.3v wired from p5 to esp and 5v connected to the gbs barrel plug input (or 2-pin header)? 100 ohm resistor at sync->ground, on the input you're trying to make work? Jumper on the 2 pin header just south of p5? Confirmed sda and scl are wired correctly between gbs and esp?

Sent from my SM-G955U using Tapatalk

[fluxcore]

Seems like that error isn't necessarily to do with insufficient power... I ended up just plugging in a screen + wii (through component) to see what would happen, and lo & behold it worked anyway. I'll try again with the 3.3v connection, don't like double regulating if I don't have to.

Gave it a bit of a play around and seems quite nice. The wifi was pretty dodgy if I set it up to connect to my local wireless system though, appears a lot more stable if that is NOT configured and you just connect to the gbscontrol itself. I think that's how I'll do it, pretty easy to just switch connections using a phone and interact with it like that.

[rama]

This is overkill but its what I do now.

Remove C11
Put 10uf Tantalum capacitor on LDO input 22uf Tantalum capacitor on LDO output
7x 22uf X7 ceramic decoupling caps fit under the stock electrolytic caps (C65 C66 C3 C4 C5 C6 C7)
2x1n caps on both sync input lines. (Replace C33 C35)
2x1000r resistors removed, one of them is replaced with a 75R to fix termination.(remove R32 replace R34)
Pots removed to fix color levels.
L1 L2 L3 removed and 220R@100 ferrite beads installed.
Ferrite bead on charge pump.(replace R58)
Charge pump decoupled with 100n cap.(Between R59 and R58)

That'd be the full list, yeah. I wouldn't replace the 1000R resistors (simply add 100 Ohm on Sync in), but the rest can be called "recommended"

Code: Select all

 no sync found
low power
<reset>

This is just what it says: There is currently no active source (sync).
This will print when the board powers up, and no source is active.
As soon as a source comes on, it will either detect it and start the output, or print a lot of "not quite working" messages.

Getting a new gbs board since mine got fried by itself (probably because I inputted TTL sync off my own lm1881 setup, since fixed using a resistor)
What would be a checklist? Can I directly connect a 12v power supply?

I actually doubt that the sync input is fried. It will probably survive a 5Vpp sync signal for quite a long time.
Using a 12V supply is not the best idea for the long term. It would be best to have something at 7V to 10V (but 1A is fine).
Depending on the GBS style, the LDO or buck converter passives may get pretty hot at 12V.
If you power the ESP8266 with those 12V as well, their LDO will also not quite like it.

There's always the option of 5V supplies, which in today's world are probably the most plentiful.
Just check your cables and connectors for dirt / oxidation buildup and don't use the cheapest you can find

@NoAffinity
The screens appear okay. Your white looks to be a little on the blue side maybe?
If you have a gray ramp (one is in the 240p test suite), all steps of that should be some kind of gray.
There should be no red, green or blue tint in it. If you have it like that, and the white is strong + the black is actual black, then you're perfect

[keremimo]

I actually doubt that the sync input is fried. It will probably survive a 5Vpp sync signal for quite a long time.
Using a 12V supply is not the best idea for the long term. It would be best to have something at 7V to 10V (but 1A is fine).
Depending on the GBS style, the LDO or buck converter passives may get pretty hot at 12V.
If you power the ESP8266 with those 12V as well, their LDO will also not quite like it.

There's always the option of 5V supplies, which in today's world are probably the most plentiful.
Just check your cables and connectors for dirt / oxidation buildup and don't use the cheapest you can find

Sync input is not fried, the whole board is It started generating INSANE amounts of heat from the power wires which lead to the Arduino, to the point that they almost melted. I was using a USB to 5V barrel cable to power it. Now it doesn't even work on OFW, or if it works, it only accepts PAL signals. NTSC consoles give no image. It is pretty much dead it was a long time coming problem probably because the board was third hand, got it very, VERY cheap.

Anyways I want to build an HDMI variant of this converter for a streamer friend of mine but I have a few questions.

https://www.aliexpress.com/item/New-Arr ... 773f51513d

This is the one I've been eyeing on because I remember Rama talking about how this one's the better variant. The issue is, I do not see the SDA SCL pins anywhere. Did anyone try this variant?

[donluca]

Rama, I *think* remember you wrote somewhere that the GBS was capable of downscaling as well... do I recall correctly?

[Ryoandr]

Rama, I *think* remember you wrote somewhere that the GBS was capable of downscaling as well... do I recall correctly?

I just tried an interlaced source, I'm guessing the deinterlacing method is just weave. Looks great on still screen but lots of combing on movements.
Not that it matters much actually , but is there a possibility of bob or adaptive deinterlace ?

[rama]

Ryoandr:
That's the best I could achieve for the time.
The big development was to get the WFF/RFF into a working state with my existing configuration.
If any of the ~30 registers required for this are wrong, all you get is screen garbage.
It wasn't much fun :p

From here on, I might find better ways to blend the fields, but at this time, it'll look like pure weave.
I think this is an improvement, since this stops the flicker headache at least, but there's always room for more

donluca:
Technically I don't see a problem. Practically, there's no preset for this yet.
Creating a preset is the same procedure as the regular upscaling options.
I need to know what the requirements are though.

keremimo:
These newest boards have a socketed MCU. They probably program the MCU beforehand, so don't need external I2C headers anymore.
The points are still available on the board, if you want to solder wires, or simply remove the MCU and solder to the socket pins.

On that note, the other day I probed the HDMI transcoder debug header on my regular HDMI version board.
This is I2C as well and it can be programmed much like the main chip.
This transcoder is in many of the $5 PS2 to HDMI or Wii2HDMI devices...

[Ryoandr]

Ryoandr:
That's the best I could achieve for the time.
The big development was to get the WFF/RFF into a working state with my existing configuration.
If any of the ~30 registers required for this are wrong, all you get is screen garbage.
It wasn't much fun :p

From here on, I might find better ways to blend the fields, but at this time, it'll look like pure weave.
I think this is an improvement, since this stops the flicker headache at least, but there's always room for more

No worries, just asking Not being a priority is plenty fine, the current state is already amazing.

[rama]

Yeah, it looks great on static or mostly static screens.
When there's motion other than the predictable line flicker though, the advanced deinterlacing methods should take over.
As I understand it now, the chip should mix and mash weave and bob, depending on the type of motion it detects.
You've got to configure the various motion detections, and then various filters that either lean to weave or to bob.

What I fear with this is that the "best" result I can get will be that of the OFW.
It's not very encouraging if that quality is to be the goal :p

[keremimo]

What I fear with this is that the "best" result I can get will be that of the OFW.
It's not very encouraging if that quality is to be the goal :p

Not necessarily disencouraging, since the CFW cleans up a very good number of other issues that plague the OFW. Nobody expects DVDO VP30 level quality from a 20 dollar board, it will be very passable with all the other optimizations combined with the OFW de-interlace

Also it doesn't attempt to de-interlace 240p content like OFW does so it is already a winner

Question: Does it re-sync when it switches to de-interlacing? (Chrono Cross, Silent Hill)

[donluca]

donluca:
Technically I don't see a problem. Practically, there's no preset for this yet.
Creating a preset is the same procedure as the regular upscaling options.
I need to know what the requirements are though.

Ideally, I'd like to use modern consoles (think PS3, X360, etc...) in true 240p (and not 480i) on my arcade cab/CRT.

It should do the following:

480i -> 480p -> 240p
480p -> 240p
(optionally, but not required) 720p -> 240p

and that's pretty much it, not interested in anything higher.

[NoAffinity]

rama:
wrt color imbalance, I took the GBS-C output directly to a VGA monitor, and it looks fine (after auto gain). The VP30 was the cause for the color imbalance. I spent about 20 minutes tuning things, had to take brightness down a few ticks, gamma correct blue and green, and a couple other minor tweaks. I stayed away from adjusting saturation, contrast and hue. One thing worth noting - if 'output level' is set video (16-235), black is dark gray, overly bright and washed out. If I set 'output level' to PC (0-255), that gets it to what you saw in the video, with all settings at default. I'm assuming that has more to do with the TV handling of the color range?

Anyway, after all this fiddling with the VP30, I believe it's much better. I will post some video or screenshots when I get a chance.

But, a question - when using the auto gain feature, is it possible to save the results to the custom profile? I have tried doing so, and setting the custom profile as the prerred profile, but it seems it is necessary to do auto gain at ever power cycle.

Lastly, what would be the best sync setting option for the GBS-C->VP30, based on the available options:
• CSync Composite Sync (on the H sync BNC connector)
• H+V+ Positive Hsync and Positive Vsync
• H+V- Positive Hsync and Negative Vsync
• H-V+ Negative Hsync and Positive Vsync
• H-V- Negative Hsync and Negative Vsync

[rama]

donluca:
I'll keep it in mind. It shouldn't be too hard to do 480(i or p) to 240p.
Any higher res will probably be trickier, as capturing at quality gets harder above 480p.
That's also the reason I do direct passthrough for 720p and up. It just looks great out of the console already, no need to scale it.

NoAffinity:
I don't work with limited color range at all. The entire gbscontrol chain is made for full RGB (0 to 255).
It's best to force your other equipment to full range as well, if you can.
Adding any limited range component will hurt quality lots.
I don't even know where to expect limited range, nor why it even is a thing yet.
I sure hope most modern TV do full range on all of their inputs..

Regarding the preset not saving the gain, maybe it's buggy? I changed so much lately that I didn't get to test everything.
It should preserve the ADC gain along with other settings such as scanlines.

Sync polarity depends on the resolution. If you have a choice, use positive (H + V) for higher resolutions, but negative for 640x480.
Combined or discrete sync is irrelevant. If your equipment supports your choice, each will look the same.

[NoAffinity]

NoAffinity:
I don't work with limited color range at all. The entire gbscontrol chain is made for full RGB (0 to 255).
It's best to force your other equipment to full range as well, if you can.
Adding any limited range component will hurt quality lots.
I don't even know where to expect limited range, nor why it even is a thing yet.
I sure hope most modern TV do full range on all of their inputs..

Regarding the preset not saving the gain, maybe it's buggy? I changed so much lately that I didn't get to test everything.
It should preserve the ADC gain along with other settings such as scanlines.

Sync polarity depends on the resolution. If you have a choice, use positive (H + V) for higher resolutions, but negative for 640x480.
Combined or discrete sync is irrelevant. If your equipment supports your choice, each will look the same.

Thanks for the feedback, rama! If I understand it correctly (from my various readings about the OSSC's features.), limited range is simply there to provide wider support for monitors. Makes sense that the DVDO products would also have that. Knowing that GBS-C only supports full range, I will stick to the output level set to "PC" on VP30, to ensure full range. But maybe something to keep in mind, if folks are having seeminly unsolvable color issues - it could be that their monitor does not support full range. Although, I believe this is not likely to be an issue with native VGA inputs. OSSC supports full range natively. So unless someone's getting overly creative like me, and using some kind of adapter VGA-to-HDMI and going to a flat screen that only supports limited range via HDMI, then it's probably a non-issue.

I had a thought - possibly after doing auto gain, simply press 'gain +' once and then 'gain -' once, and that will provide some kind of actual setting for profile saving to capture. I'll give that a try tonight.

Good to know on sync polarity. I don't really notice a difference when changing between the available options. If there is any, it's very minor. I will keep those recommendations in mind.

[donluca]

donluca:
I'll keep it in mind. It shouldn't be too hard to do 480(i or p) to 240p.
Any higher res will probably be trickier, as capturing at quality gets harder above 480p.
That's also the reason I do direct passthrough for 720p and up. It just looks great out of the console already, no need to scale it.

That would be absolutely fantastic. Also, keep in mind arcade monitors (for use in a cab) expect a 5Vpp across the RGB rails and, most important, *not* AC coupled, otherwise the brightness of the picture would vary depending on the content.

[Ryoandr]

donluca:
I'll keep it in mind. It shouldn't be too hard to do 480(i or p) to 240p.
Any higher res will probably be trickier, as capturing at quality gets harder above 480p.
That's also the reason I do direct passthrough for 720p and up. It just looks great out of the console already, no need to scale it.

That would be absolutely fantastic. Also, keep in mind arcade monitors (for use in a cab) expect a 5Vpp across the RGB rails and, most important, *not* AC coupled, otherwise the brightness of the picture would vary depending on the content.

I doubt the board can produce 5Vp-p on the RGB channels as VGA is 0.7Vp-p. You need an amp to get that level of voltage.
On a side note, I measured MVS RGB levels around 3.3Vp-p.

[rama]

Yeah, this definitely requires some exotic amplifier.
I don't know of any device that would require "high voltage" RGB, that also has to be dangerous by being DC coupled.
Apparently, RGB arcade monitors are the exception, so if such an amplifier exists, then in that market.

NoAffinity:
I figured as much with the limited range deal.
The immediate issue case is HDMI. When a transcoder is used, and it connects to a TV via HDMI, sometimes the TV will cleverly decide to use limited range.
My PC monitor is an example, and I can't select the range manually either.
I think it's possible to send an HDMI flag that requests full range, and that most stubborn displays should accept it.
That's why I hooked up to the I2C on my HDMI GBS board ;p
So far no luck though. There's just no documentation on the transcoder at all.

The device:
MacroSilicon MS9282

[Ryoandr]

Could JVS bi/tri sync monitors accept 15khz 0.7Vp-p through their VGA input ? They should right ?
Donluca, I don't know what kind of arcade cab you have. If you have a classic JAMMA monitor then you would need something like Tim's SCART to JAMMA, but it's not made anymore it seems.

[NoAffinity]

rama:
here's some screen grabs and short video capture, with the VP30 dialed in a bit better. Output from GBS-C directly to a VGA monitor is spot on, when auto gain is used. That really is a nice feature, and I'm just going to be in the habit of "auto gaining" when I start a new game. Most consoles and/or games have bright or all white intro screens, which is helpful.

I think I need to spend a bit of time dialing in my capture card settings, using a color bar screen. The TV I'm playing on while capturing looks absolutely perfect. The capture card is still just a bit off, but I think, is much improved.

GBS output @ 1280x1024 to VP30 output at 1080p.

Video: https://youtu.be/fn-Cs_jYX1g

Screenshots (click through to see full size):

Spoiler

[Ryoandr]

Something I always forgot to ask, can it output composite sync over the H pin ?

[donluca]

Donluca, I don't know what kind of arcade cab you have. If you have a classic JAMMA monitor then you would need something like Tim's SCART to JAMMA, but it's not made anymore it seems.

Exactly my point. I've tried several other solutions with abysmal results.

I just want something which "just works" once set up, without fiddling afterwards.

Also, just as a FYI, VGA signals are DC coupled, as far as I know only RGB through scart is AC coupled.

Arcade RGB monitors generally accept from 2 to 5 Vpp RGB signals, IIRC standard VGA can reach up to 1,5Vpp which may be enough. Again, amplification is not an issue, but doing a proper voltage clamp has proved to be quite an headache. This is why I'm way more interested in a proper DC coupled output signal.

EDIT: I have a SEGA Astro City cab with its original Nanao MS8 29" monitor

[Ryoandr]

without the 75R termination, VGA RGB voltage will be around 1.4 / 1.5 yeah.

[Ryoandr]

Just a Public Service Announcement, be sure to use clean power supply.
During pretty much the last month, I used original Sega power supply (linear) with MD and PC power supply (high quality switching) for MVS.
Today I received a 5V3A wallplug switching power supply for the MVS, and the GBS-C can't sync on with it. A quick look at a scope show a huge amount of switching noise.

I'm currently wondering if a brick-type or a cage-type would do a better job. I would prefer a non exposed solution like a brick, but if the cage type is better I'll just go with it. I need 3A (MV1A is among the least hungry MVS board thankfully).

[TheFellowJasper]

Hello everyone, looking forward to get myself GBS and use it with gbs-control. Few things made me wonder tho.

1. On Aliexpress most, if not all boards are shown as a older version which have the charge pump mentioned on rama wiki. Is it just their laziness and they ship the new version anyway or you can still get a old version from them?
Never mind about that. I looked on images again, and they're in fact V5.0
2. Aside from the LDO & pots removal, sync separation and bringing impedance to 75ohm, what hardware mod can I do to (potentially) improve image quality and stability of operation? I'll be using GBS with PSX (7502) over SCART RGB and maybe with PS2 (Slim and later FAT when I get one) over component or even VGA later on (RGsB or RGBHV, not sure yet).

3. Does someone tested how much does GB8200 draw power? I have a 1A max brick which can output anywhere from 3V to 9V (in 1.5V increments) and 12V and I'm not entirely sure if it will be enough for atleast GBS and LM1881 (with or without voltage regulation down the line).