GBS 8200/8220 CFW Project

[gingerbeardman]

Thanks. But I'm better at web development than electronics. I guess I would needto make an additional circuit but at that point I'm lost.

[MikeIronFist]

Is it possible to automate the resistor removal when higher sync signals are coming in?

I use with PC, DC, Wii, PS2 so 50/50 resistor and not.

Gonna assume you're using RGB for both PS2 and Wii rather than component?

You really don't need the 100 ohm terminating resistor in parallel if you're only using Csync. You can just put a 470-680 ohm resistor in series on your SCART input's sync line, leaving out the additional terminating resistor. In conjunction with 500 ohm resistor on the Hsync line, it will ensure that you divide the csync voltage to safer levels for RGBs. And since it's not connected to ground at all, it won't interfere with the RGBHV input. This is the method I currently use.

If your PS2 SCART cable is sync-on-luma and fails to work with this method, you could always add a sync stripper to convert it to Csync; RetroRGB has a great guide for integrating a sync stripper directly into your SCART cable if necessary.

In terms of automatic switching, I've spent a good amount of time today experimenting with using a relay to connect or disconnect the Sync wire on the 8-pin adapter depending on whether a given device is on, but I haven't been able to find a universally reliable source to trigger the relay outside of the SCART Aspect Ratio Switch Pin (SCART Pin 8), which is not ideal for PAL consoles since there's some that output 5v (PS2, Megadrive), some that output 12v (Dreamcast, Wii, SNES) and I think one or two that output 9v??? (Saturn) so you'd either need a 5v or 6v relay with some *very* wide tolerances or you would have to implement some sort of voltage regulation circuit, which IMO would be a bit much.

[gingerbeardman]

I'm not using SCART at all. Component for Wii/PS2 and VGA for PC and DC.

[MikeIronFist]

I'm not using SCART at all. Component for Wii/PS2 and VGA for PC and DC.

Oh snap! in that case, get that 100 ohm resistor out of there! You don't need it. The Component inputs work on the stock board and the 100 ohm resistor between Sync and Ground doesn't even affect them.

EDIT: or just leave it switched off, but either way you don't need it unless you're using RGBs and even then, like I mentioned above, there's alternative ways to handle the sync signals for RGBs that don't interfere with RGBHV/VGA functionality.

[gingerbeardman]

Boom! Thanks.

[DanAdamKOF]

Hi there! I just put a GBS Control board together, I did a quick test and I like the results!

A few questions:
How do I set Wifi to return to using the self-hosted gbscontrol network? I think the area of the house I plan to use GBS Control in is too far to reach my network reliably. I was using GBS Control OK in that area for a while, then it seems to have disconnected. I tried the reset defaults option on the web UI, and reflashing from the Arduino IDE, but it's still connecting to my network.
Edit: Somehow it returned to using the gbscontrol network. Maybe it does it when it can't find the network? Anyway I think this is problem solved.

Is there a way to create a custom output resolution? There aren't any resolutions on the presets tab that are integer multiples of 384p (24khz video). I'd like to output 1152p or 768p etc.

I didn't mess with this much, but it seemed like clicking different presets on the presets page wasn't actually outputting a new resolution.
Edit: I think this may have been a network issue. Clicking things has the expected result now.

What does the red dot that appears in the web UI mean?

I might want to use more than one GBS Control setup at some point. Is there a way to set each to have a different SSID for its self-hosted network? Assuming I improve my wifi, would I have to use IP addresses to access each, or could a unique URL be set for each?

Edit: One other thing, I can't fit the whole width of my PCB's signal within GBS Control's output. I can reduce the width a few steps, but it starts displaying garbage to the right after too many of them. I can move the signal around and get each edge to appear, but of course that's off-center and cuts off the other side's edge. My source is a djmain PCB (in a beatmania cabinet) which is 24khz.

Thanks so much!

[allenb]

I'm not using SCART at all. Component for Wii/PS2 and VGA for PC and DC.

Oh snap! in that case, get that 100 ohm resistor out of there! You don't need it. The Component inputs work on the stock board and the 100 ohm resistor between Sync and Ground doesn't even affect them.

EDIT: or just leave it switched off, but either way you don't need it unless you're using RGBs and even then, like I mentioned above, there's alternative ways to handle the sync signals for RGBs that don't interfere with RGBHV/VGA functionality.

Is there an elaboration on when the resistor is/isn't needed? Is it when you are feeding RGBs signals vs RGBHV?

[maxtherabbit]

Is there an elaboration on when the resistor is/isn't needed? Is it when you are feeding RGBs signals vs RGBHV?

no, it's for when your source device's sync output is expecting a 75-ohm termination (e.g. luma, CVBS)

[MikeIronFist]

A few questions:
How do I set Wifi to return to using the self-hosted gbscontrol network? I think the area of the house I plan to use GBS Control in is too far to reach my network reliably. I was using GBS Control OK in that area for a while, then it seems to have disconnected. I tried the reset defaults option on the web UI, and reflashing from the Arduino IDE, but it's still connecting to my network.
Edit: Somehow it returned to using the gbscontrol network. Maybe it does it when it can't find the network? Anyway I think this is problem solved.

Yep. Also reflashing actually won't overwrite the Wifi settings. You specifically have to select "Erase Flash:" > "Sketch + WiFi Settings" in the IDE.

Is there a way to create a custom output resolution? There aren't any resolutions on the presets tab that are integer multiples of 384p (24khz video). I'd like to output 1152p or 768p etc.

Nah, the output modes just are what they are.

What does the red dot that appears in the web UI mean?

It means "waiting for a response from the host;" you see it when the ESP8266 is either busy or when it's disconnected from the network

I might want to use more than one GBS Control setup at some point. Is there a way to set each to have a different SSID for its self-hosted network? Assuming I improve my wifi, would I have to use IP addresses to access each, or could a unique URL be set for each?

I believe the default network settings are included in the sketch; you should be able to edit it in the Arduino IDE to make one with a different SSID that requests a different local domain name.

Edit: One other thing, I can't fit the whole width of my PCB's signal within GBS Control's output. I can reduce the width a few steps, but it starts displaying garbage to the right after too many of them. I can move the signal around and get each edge to appear, but of course that's off-center and cuts off the other side's edge. My source is a djmain PCB (in a beatmania cabinet) which is 24khz.

It might be that the border mask is cutting off that side. Try hitting "Horizontal-" a couple of times under the Border Mask settings.

[DanAdamKOF]

Thanks for the help!

I did try horizontal- but after a few steps it showed garbage on screen and still didn’t show the whole signal. I was using my capture card’s VGA input to check it and I realized that it’s possible that my card could be cutting off parts of the signal, and GBS-Control might already be showing most or all of the signal. I’ll try some other tests to confirm.

I would like to feature request some resolutions which favor 384p sources. I’ll write this on github later.

One thing I was thinking about, is it possible, in theory, for GBS-Control to take in a 120hz signal and output at 60hz? I have a somewhat convoluted use case that could potentially really benefit from this.

[MikeIronFist]

I did try horizontal- but after a few steps it showed garbage on screen and still didn’t show the whole signal. I was using my capture card’s VGA input to check it and I realized that it’s possible that my card could be cutting off parts of the signal, and GBS-Control might already be showing most or all of the signal. I’ll try some other tests to confirm.

Try moving the picture to the right a bit until the whole thing is visible, then you can try moving the whole framebuffer back into a more centered position by going into the "Development" section of the Web UI and using the HS Left and Right buttons. This will all get saved when you save to one of the Custom preset slots.

[gingerbeardman]

Often I have PC on VGA while gaming on Component and switch between the two.

Can I choose which input to display? Component or VGA?
Ideally I'd also like a preset for each that is auto-selected.

I could send 1280x960 and 1600x1200 from my PC to Extron and downscale to 640x480.
These input resolutions don't work on GBS for me. Is this expected behaviour?

Finally, is it possible to unify the output settings?
Output from Component and VGA require different sync settings on my monitor.
My display is 640x480 so that is the only resolution I output at.

I'm coming from an Extron which has front buttons to switch inputs, per-input settings, and one unified output setting so I never have to change my monitor settings. I'd like to replace the Extron because it uses more power, has a little more lag, and can't do 240p, though it does seem to support higher input resolutions.

[dentnz]

I setup a GBS Control earlier today and was experimenting with downscaling to a PVM via an Extron DVS 304 in RGB pass thru mode. I am running a Wii at 480p into the GBS via component. From there I have ensured that the GBS is set to 15khz downscale.

Though I get a nice clean 240p picture (with scan lines), it's rolling vertically. The roll is quite a slow one.

Is there something I can do with the GBS (vhold?). Or is there a chance that the extron isn't combining the sync on the output - as in, it's a true pass thru?

Thanks! And this project is awesome!!!

[allenb]

if your CRT TV is 15khz and you need 480p/i downscaling or simple RGB to YPbPr 15khz transcoding

ok, so this doesn't downscale. it's a what-goes-in is what-goes-out situation. so what is it used for then (when outputting to a 15kHz CRT)?

i mean, if you're already pushing 15kHz RGBS out of your analog output via CRT emudriver, what is adding the GBS doing to the signal?

the GBS can and does downscale, it can also act as a passthrough transcoder

I am having trouble with passthrough transcoding. If I set my input to 15kHz downscale I am getting an image, but it is a bit jumpy. When I try passthrough it doesn't transcode to ypbpr, but the image looks much more clear than the downscaled image?

Is there a setting that I need to change?

[TheDrifter363]

Hey guys what's up,

So I recently set up the 8200 with all the mods listed in the github wiki. Things like the parallel capacitors, electrolytic cap replacement, clock mod (no idea what that does, just thought I'd do it), pots removal, etc. Everything's working great, got stuff working at 1080p. I have a scart2dvi from insurrection industries, and I'm using that to get my scart games working on the vga input.

I notice, in 480i, there's these weird speckles, like white snow. There's not a lot of them, and they're mainly on black screens. I noticed it in the playstation startup logo, all over the ps2, and resident evil 2 for the n64. I don't know why these are here and how can I fix them. Thought I would post it.

On a aesthetic issue, are there any cases for all this. I have a rat's nest of bare pcbs next to my TV. Things like the scart2dvi, gbs 8200 v4, and the ebs8266 hanging on the side. I had the wifi on top of the 8200, but I noticed signal issues, so I moved it with female jumper cables. I also have the clock mod on top of that silver heatsink, don't know if that's gonna cause signal issues. Everything's insulated with electrical tape, kapton tape, and 3m double sided sticky tape.

Any ideas?

Everything's going into my TV's VGA input, but I'm gonna get one of those porta VGA to HDMI converters to hook up to my HDMI switch.

I really like the seamless 480i/240p switch. Thanks rama! This is gonna replace my OSSC. Just need to sell that now.

Oh! One last thing. On 1080p, I have the wii set to 16:9, and that's going into the component input of the 8200. Thing is the 8200 is locked at 4:3. So 4:3 systems look great at 1080p, but 16:9 is squished. Any fixes? I tried picture adjustment, but the display got corrupted when I messed with the scaling settings. Don't know what's up with that.

[Ryoandr]

1080p preset is made to be pillar-boxed for 4/3 content. You can't stretch it to full width.

If you want 16/9 content you need to use 720p preset.

[gingerbeardman]

I notice, in 480i, there's these weird speckles, like white snow.

Try some different power supply options: cables/adapters/psu.

What worked for me was going straight to the wall rather than through my multiplug power extension cable.

[TheDrifter363]

1080p preset is made to be pillar-boxed for 4/3 content. You can't stretch it to full width.

If you want 16/9 content you need to use 720p preset.

Sweet thanks! I tried 720p and it works great. Got different slots for the Wii and Gamecube since they both support 480p, but the Wii is native 16:9.

Try some different power supply options: cables/adapters/psu.

What worked for me was going straight to the wall rather than through my multiplug power extension cable.

Yeah right now the power cable is going to my multi usb power adapter. I have that running just about every 5V device I have. But if that's causing switching noise or some other nonsense, I can put it directly to my power strip, or to the wall. I'll try it out.

[Ryoandr]

Sweet thanks! I tried 720p and it works great. Got different slots for the Wii and Gamecube since they both support 480p, but the Wii is native 16:9.

I'm pretty sure you can set Wii to 4/3 ratio

[gingerbeardman]

Yes you can. I play my Wii exclusively 4:3 on a 480p LCD

[dentnz]

I setup a GBS Control earlier today and was experimenting with downscaling to a PVM via an Extron DVS 304 in RGB pass thru mode. I am running a Wii at 480p into the GBS via component. From there I have ensured that the GBS is set to 15khz downscale.

Though I get a nice clean 240p picture (with scan lines), it's rolling vertically. The roll is quite a slow one.

Is there something I can do with the GBS (vhold?). Or is there a chance that the extron isn't combining the sync on the output - as in, it's a true pass thru?

Thanks! And this project is awesome!!!

I was able to resolve my issues here. The Extron DVS304 does NOT combine sync when in RGB pass thru mode - yet another reason to throw this scaler into the bin I guess

Instead, I added the new passive sync combiner circuit hacked into an old AV cable I had:
https://www.retrorgb.com/building-a-pas ... biner.html

And that did the trick. 480p component transcoded and downscaled to stunning 240p... no rolling! Highly recommend that circuit.

I'm now trying to work out how to pass in a 480p RGBHV signal for downscale (e.g a laptop, a copy of groovyarcade). Unfortunately, Xrandr doesn't recognised the GBS VGA port as being connected when I attach it to display port 1 via a DP to VGA adapter.

Wondering what the best way might be of getting HDMI and/or RGBHV into the GBS for downscaling purposes?

[MikeIronFist]

Often I have PC on VGA while gaming on Component and switch between the two.

Can I choose which input to display? Component or VGA?

Not easily, but there's slightly hack-y things you could do to make it switch inputs so you don't have to keep unplugging cables (or wire up your own switcher.)
Input is automatically selected based on where sync is detected when there's no other signal. So if you had a script that turned off your VGA output from your PC (let's say temporarily even, like for 5 seconds) you could turn on a component console, run the script and the GBS would go to No Signal mode, then detect the sync from the Component signal and switch to Component input.

Ideally I'd also like a preset for each that is auto-selected.

I believe RGBHV/VGA will be detected differently (categorized under a VGA preset) rather than the Component signal which is categorized under the "EDTV" preset if it's 480p, if not NTSC or PAL. The system considers these signal types to be separate presets that can live together on one slot with separate settings. So you can dial in your settings for Component while that input is active, hit save on the same slot as you were using for your VGA preset and it will only load those settings for those specific signal types. In your use case, you can probably just save everything to one preset slot and leave it active and all should be well. (Hopefully!)

I could send 1280x960 and 1600x1200 from my PC to Extron and downscale to 640x480.
These input resolutions don't work on GBS for me. Is this expected behaviour?

GBS Control is actually listed as supporting VGA resolutions up to 1600x1200 so it should work. What are you seeing in the log window of the web interface when you send your board a 1600x1200 signal?

Finally, is it possible to unify the output settings?
Output from Component and VGA require different sync settings on my monitor.
My display is 640x480 so that is the only resolution I output at.

I'm coming from an Extron which has front buttons to switch inputs, per-input settings, and one unified output setting so I never have to change my monitor settings. I'd like to replace the Extron because it uses more power, has a little more lag, and can't do 240p, though it does seem to support higher input resolutions.

This bit is honestly a mystery to me. The board outputs standard VGA by default so in theory there shouldn't be any issues with sync on a standard VGA monitor. What changes to your monitor's sync settings do you normally have to make to make the sources work?

[MikeIronFist]

I setup a GBS Control earlier today and was experimenting with downscaling to a PVM via an Extron DVS 304 in RGB pass thru mode. I am running a Wii at 480p into the GBS via component. From there I have ensured that the GBS is set to 15khz downscale.

Though I get a nice clean 240p picture (with scan lines), it's rolling vertically. The roll is quite a slow one.

Is there something I can do with the GBS (vhold?). Or is there a chance that the extron isn't combining the sync on the output - as in, it's a true pass thru?

Thanks! And this project is awesome!!!

I was able to resolve my issues here. The Extron DVS304 does NOT combine sync when in RGB pass thru mode - yet another reason to throw this scaler into the bin I guess

Instead, I added the new passive sync combiner circuit hacked into an old AV cable I had:
https://www.retrorgb.com/building-a-pas ... biner.html

And that did the trick. 480p component transcoded and downscaled to stunning 240p... no rolling! Highly recommend that circuit.

Yeah, there's only two options for output: RGBHV and YPbPr. So you either need to use a sync combiner or, for YPbPr make a simple VGA-to-RCA adapter cable to get it to work. I use YPbPr output mode when downscaling, since I already had a 4 BNC cable soldered up for experimenting with MiSTer. You don't any connection to the VGA sync pins for this; the Green pin already correctly carries the Luma/Sync signal on its own.

I'm now trying to work out how to pass in a 480p RGBHV signal for downscale (e.g a laptop, a copy of groovyarcade). Unfortunately, Xrandr doesn't recognised the GBS VGA port as being connected when I attach it to display port 1 via a DP to VGA adapter.

Wondering what the best way might be of getting HDMI and/or RGBHV into the GBS for downscaling purposes?

In my experience, HDMI-to-VGA adapters and an HDMI-to-YPbPr transcoder have both worked for downscaling. I personally prefer HDMI-to-YPbPr, GBS Control just seems to handle Component video input better than it handles RGBHV and the audio RCA jacks on the transcoder are super convenient. Both adapters are detected as active displays by my Linux laptop even when nothing is plugged into their outputs, so you shouldn't have any trouble using them with xrandr either.

[TheDrifter363]

Hmm so I tried different 5V power supplies along with a 7.5V power supply and that snow pattern was still there for 480i. I'm not sure what the issue is, and it only affects 480i. I'll try to post a picture or video to show you guys. I'm hoping other people here have had the same issue, so I can get some suggestions. I'll also post my setup, so you can see what's going on.

https://imgur.com/a/SU579VT

You should see on the ps1 video the switch from 480i to 240p, the speckles disappear. It's weird.

Setup is a gscartsw to a scart2dvi (from insurrection industries), to the gbs 8200 (with gbs control), to a Samsung 40 inch TV from 2009. I'm gonna get a portta vga to hdmi soon, so I can route everything into my hdmi switch. According to Bob from RetroRGB, it's a no lag ADC. I already got the HDMI to VGA variant for my PC CRT. That's great for these old systems. Gotta test it my retro games though, only tested it out with the Switch so far.

Btw a note, I noticed the audio output from the scart2dvi to my TV is really low in comparison to the OSSC I had before. That one, the gscartsw was directly plugged into the OSSC. The Wii's audio goes directly to the TV through a stereo audio to 3.5mm adapter. I'm using HD Retrovision cables for that. The Wii doesn't have the same audio problems, it's as loud as everything else. I don't know if the scart2dvi is decreasing audio amplitude, or volume, in some way. Weird. Don't know how to fix that. Anyone have any issues?

[MikeIronFist]

Hmm so I tried different 5V power supplies along with a 7.5V power supply and that snow pattern was still there for 480i. I'm not sure what the issue is, and it only affects 480i. I'll try to post a picture or video to show you guys. I'm hoping other people here have had the same issue, so I can get some suggestions. I'll also post my setup, so you can see what's going on.

https://imgur.com/a/SU579VT

You should see on the ps1 video the switch from 480i to 240p, the speckles disappear. It's weird.

The guy from Retromancave had this same issue with his Amiga on his GBS-8220, and he eliminated it by using copper tape to shield the traces on the underside of the board. You can check out the video here.
However, before you buy any more materials or do any further modification, make sure you try the board with other VGA displays just to be sure that it's not your TV; some HDTVs do have some really poor VGA inputs, they're such a low priority for some manufacturers.

Btw a note, I noticed the audio output from the scart2dvi to my TV is really low in comparison to the OSSC I had before. That one, the gscartsw was directly plugged into the OSSC. The Wii's audio goes directly to the TV through a stereo audio to 3.5mm adapter. I'm using HD Retrovision cables for that. The Wii doesn't have the same audio problems, it's as loud as everything else. I don't know if the scart2dvi is decreasing audio amplitude, or volume, in some way. Weird. Don't know how to fix that. Anyone have any issues?

OSSC buffers and converts the audio signal from your SCART cable. SCART2DVI simply passes it through. A lot of HDTVs' 3.5mm audio ins are pretty high impedance and tend to give weak results with a lot of sources, since they're meant for PC audio outputs more than anything else. The Wii has fairly loud audio output IMO, so it's not too surprising that it sounds fine going through your 3.5mm in. You might see much better results with your VGA-to-HDMI ADC, in my experience they tend to take SCART audio well without over-attenuating.

[TheDrifter363]

Mike you're awesome man. I'm gonna take a look at what you said in detail and try to implement some of this stuff. At the end of the day, all of this is gonna go through that VGA to HDMI ADC, so I might wait on that before doing further testing. This is good for reference material though, if that ADC doesn't clear stuff up.

[rama]

For the speckles in 480i, try different SDRAM speeds (development > Cycle SDRAM Clock Speed).
Is this definitely an NTSC source, or PAL?

[mutmut02]

Hi ! I l must first admit I have not been through the whole topic as it's now quite long, and I have not found the answer on Github.

Could the GBS control be able to downscale 720p or 1080p coming from a PS4 to 15Khz in order to use this system on a consumer CRT, using a Tendak Active 1080P Female HDMI to VGA Male Converter ?

[Gollot]

Hello i'm about to build mine and i have a couple of questions, first i'm going to print this 3D Shell https://www.thingiverse.com/thing:3459749 Should i do the one with buttons? I mean are the buttons usable after you install the cfW? Another question, is also recomendable to use a on/off switch? is there any risk of damaging it from just unplugging the unit to turn it off?

And the last question is about this video that i'm using as a guide,

https://youtu.be/ZftKgnI0gvM?t=748 on this video (Minute 12:28) Is safe to wire the power source of an active HDMI to VGA converter directly on the board? I mean it would cause any kind of interference or noise on the image?

Thanks for your time.

[gingerbeardman]

if you had a script that turned off your VGA output from your PC (let's say temporarily even, like for 5 seconds) you could turn on a component console, run the script and the GBS would go to No Signal mode, then detect the sync from the Component signal and switch to Component input.

I'll see if I can set that up, but it seems as if it would only be a one way solution? I would have to turn off the console to get back to PC? This is a problem when streaming

In your use case, you can probably just save everything to one preset slot and leave it active and all should be well. (Hopefully!)

I'll try this, too.

GBS Control is actually listed as supporting VGA resolutions up to 1600x1200 so it should work. What are you seeing in the log window of the web interface when you send your board a 1600x1200 signal?

1280x960 - photo of what I see https://imgur.com/a/xiwYxFx

Code: Select all

(H-PLL) rate: 1966 state: 2
(SP) HS active low
(SP) VS active low

HD_HSYNC_RST : 1023
HD_INI_ST    : 0
HS ST/SP     : 16 0
HB ST/SP     : 3976 208
------
VS ST/SP     : 7 2
VB ST/SP     : 0 20
CsVT         : 987
CsVS_ST/SP   : 4 1

1600x1200 - photo of what I see https://imgur.com/a/rMii978

Code: Select all

`(H-PLL) rate: 4687 state: 5
(SP) VS active high

HD_HSYNC_RST : 1023
HD_INI_ST    : 0
HS ST/SP     : 16 0
HB ST/SP     : 3976 208
------
VS ST/SP     : 2 7
VB ST/SP     : 0 20
CsVT         : 1249
CsVS_ST/SP   : 4 1

This bit is honestly a mystery to me. The board outputs standard VGA by default so in theory there shouldn't be any issues with sync on a standard VGA monitor. What changes to your monitor's sync settings do you normally have to make to make the sources work?

Depending on the input resolution, I have to do auto adjust to get the correct phase/clock/horiz/vertical on my monitor (actually TV PC/VGA input).

My expectations were that if I am always uing the same downscaled output resolution (480p) then I should not have to adjust the monitor for each input resolution. This is how the Extron works.