GBS 8200/8220 CFW Project

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NoAffinity
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Re: GBS 8200/8220 CFW Project

Post by NoAffinity »

Quick update on trying that passive sync combiner circuit that is detailed on retrorgb. It doesn't work well with the GBS. Testing with Dreamcast->VGA in on the GBS. 1920x1080 is at least viewable, but has a significant and constant tear/distortion line at about 2/3 of the image height. Certainly not playable. All other resolutions are scrambled, jumpy, over-saturated with green. I didn't even bother trying to downscale. If it's not an all-in-one solution, it doesn't work for me.
retromaniak
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Re: GBS 8200/8220 CFW Project

Post by retromaniak »

Welcome. I have an idea, but I wonder if anyone has already tried to implement it. I wonder if it would not be worith trying to get GBS schematics? In the sense of what I have seen, gonbes has not been interested in this scaler for a long time, and since GBS-C AIO is already being created, if you had the schematic, it would be possible to implement all the modifications directly on the PCB, and maybe even redesign it in such a way as to obtain even more better image quality than even with AIO.

although of course this is just my loose proposition. Maybe it's worth a try ...
immaburr
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Re: GBS 8200/8220 CFW Project

Post by immaburr »

Since the bulk of my systems go into my gscartsw I've been trying to find the right SCART to Input to my modified GBS8200.

https://i.imgur.com/KgxZCDf.jpg

Originally I tried the SCART2DVI solution: https://insurrectionindustries.com/product/scart2dvi/ (is 404 atm)

https://www.retrorgb.com/scartcleaner.html

This works great and is truly a plug and play solution into the GBS8200 but I'm just not a huge fan of all the cables. I also notice that the D1 Mini board stays lit blue when a signal is passed to it.

The other device I picked up from ebay: https://tinyurl.com/y2pqdrgr

It "works" but with some major caveats. If I plug in the GBS cold I have to go into the interface and select "720x480 / 768x576" twice (I take it to bump it to 480p) Also, whenever the signal is being passed through the D1 Mini board may blink the blue LED but it never stays static.

I've also noticed diagonal waves on the picture strictly from the Electronica4u ebay converter. I've tried removing the 100ohm resistor and this made no difference.

Would be great if another run of these were done: https://www.retrorgb.com/tinkerplunk-ha ... a-pcb.html but it looks like he's wrapped up in the AIO project atm.

Just thought I would share my findings so far.
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RoboArmy
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Re: GBS 8200/8220 CFW Project

Post by RoboArmy »

I've been posting about the GamesCare gbs control package and I feel like I have to come here to clarify things, for those who considered buying one from them in Brazil.

I've been talking with Fabio from GamesCare and I apparently missed the fact that I was supposed to ask for the clockgen mod as it is done on demand (per-request). So my fault entirely for having a clockgen-less unit, in fact he just charged me the cost of the parts when I shipped my GBS back to him for the clockgen. Great user support! So yeah if anyone had any doubts about it you can now order it (but you gotta make sure you ask him for the clockgen mod to avoid shipping the unit back and forth unecessarily).

Now I got rid of tearing entirely... well not exactly 100% entirely because one of the games I'm playing heavily behind the GBS, Silent Hill, actually does tear even on composite output, so I have to live with that lol. Otherwise I had no issues with tearing at all anymore. If anyone built their own units I'd highly recommend installing a clockgen anyway even if you don't think you'll need it to avoid some headaches.
Ryoandr
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Re: GBS 8200/8220 CFW Project

Post by Ryoandr »

Tested another Neogeo AES, and it also didn't work properly, diagonal fast rolling image at worst, unstable image with big upper skew at best.
So far I'm at
AES 3-4
AES 3-5 x2
AES 3-6
MVS MV1-FZ

with the same symptoms.
Because an MVS is also affected, I don't think it's because of slight frequency differences.
strayan
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Re: GBS 8200/8220 CFW Project

Post by strayan »

Any idea why I’m getting this slow rolling horizontal line? Disappears for a few minutes before returning: https://youtu.be/rR2yio9rcHg

Also, check out how well GBSC handles PAL DVD’s (on a PAL PS2) https://imgur.com/a/1a7tGXo
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NoAffinity
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Re: GBS 8200/8220 CFW Project

Post by NoAffinity »

strayan wrote:Any idea why I’m getting this slow rolling horizontal line? Disappears for a few minutes before returning: https://youtu.be/rR2yio9rcHg

Also, check out how well GBSC handles PAL DVD’s (on a PAL PS2) https://imgur.com/a/1a7tGXo
The horizontal line is screen tearing. Do you have the clock gen mod?

I have also seen it when using vga->hdmi converters (with clock gen installed).

DVD looks great!

Sent from my SM-G955U using Tapatalk
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Kez
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Re: GBS 8200/8220 CFW Project

Post by Kez »

I have actually had that tearing a couple times since I installed the clock gen mod.. Never had it before. Not sure if I'm on the latest fw though.
Fluor
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Re: GBS 8200/8220 CFW Project

Post by Fluor »

Hey guys, I finally got to work on my GBS and I am really close on having it working perfectly.

My main goal was to connect my computer to my consumer CRT (240p, 15khz), downscaling the signal.

Here's a short video of what's going on: https://streamable.com/ch9ki3

As you can see, when I click on 15khz downscale preset, it shows the image perfectly of my extended desktop for a split second, before getting messed up again.

I was afraid my soldering job was garbage and something else could be messed up, but seeing it working correctly, even if for just a little bit, must be a sign that it's just a small thing that is holding it back.

The signal is coming from my rtx3080, where I created a custom resolution. I tried many types, 480p, 480i, 240p etc, they all ended up with the same shenanigans.

When reading the text lines, I noticed the following message: "sync skipped sfr wrong: 0.00"

I looked it up in this thread, and even Rama talked about it being a problem with the debug pin, but it looks more than fine after I checked the board.

Let me know if there's anything I can try, it feels like it's so close on being ready to enjoy, I can almost taste it. Thank you very much for the help.
strayan
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Re: GBS 8200/8220 CFW Project

Post by strayan »

Kez wrote:I have actually had that tearing a couple times since I installed the clock gen mod.. Never had it before.
NoAffinity wrote:Do you have the clock gen mod?
Yep, clock gen installed.

Was tinkering last night and seems like it goes away if I disable the Line Filter.

On a side note I’d really like to see a ‘Weave’ option added to the de-interlace options so we have the choice between ‘Motion adaptive(bob+weave)/Bob/Weave
Last edited by strayan on Thu Oct 15, 2020 1:48 am, edited 1 time in total.
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NoAffinity
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Re: GBS 8200/8220 CFW Project

Post by NoAffinity »

Fluor wrote:Hey guys, I finally got to work on my GBS and I am really close on having it working perfectly.

My main goal was to connect my computer to my consumer CRT (240p, 15khz), downscaling the signal.

Here's a short video of what's going on: https://streamable.com/ch9ki3

As you can see, when I click on 15khz downscale preset, it shows the image perfectly of my extended desktop for a split second, before getting messed up again.

I was afraid my soldering job was garbage and something else could be messed up, but seeing it working correctly, even if for just a little bit, must be a sign that it's just a small thing that is holding it back.

The signal is coming from my rtx3080, where I created a custom resolution. I tried many types, 480p, 480i, 240p etc, they all ended up with the same shenanigans.

When reading the text lines, I noticed the following message: "sync skipped sfr wrong: 0.00"

I looked it up in this thread, and even Rama talked about it being a problem with the debug pin, but it looks more than fine after I checked the board.

Let me know if there's anything I can try, it feels like it's so close on being ready to enjoy, I can almost taste it. Thank you very much for the help.
How are you connecting to the gbs? Downscaling the vga input does not work reliably. If this is your setup, a vga to rgbs or vga to component converter is your best bet for input to the gbs.

Sent from my SM-G955U using Tapatalk
Fluor
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Re: GBS 8200/8220 CFW Project

Post by Fluor »

NoAffinity wrote:How are you connecting to the gbs? Downscaling the vga input does not work reliably. If this is your setup, a vga to rgbs or vga to component converter is your best bet for input to the gbs.

Sent from my SM-G955U using Tapatalk
HDMI from my RTX3080, to this HDMI to VGA: https://www.amazon.ca/gp/product/B07BN8 ... UTF8&psc=1

VGA to the VGA input in the GBS

GBS VGA out to this VGA to component converter: https://www.amazon.ca/gp/product/B00213 ... UTF8&psc=1

Then a male to male HD Retrovision set of cables into my CRT component input.
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kitty666cats
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Re: GBS 8200/8220 CFW Project

Post by kitty666cats »

Fluor wrote:
NoAffinity wrote:How are you connecting to the gbs? Downscaling the vga input does not work reliably. If this is your setup, a vga to rgbs or vga to component converter is your best bet for input to the gbs.

Sent from my SM-G955U using Tapatalk
HDMI from my RTX3080, to this HDMI to VGA: https://www.amazon.ca/gp/product/B07BN8 ... UTF8&psc=1

VGA to the VGA input in the GBS

GBS VGA out to this VGA to component converter: https://www.amazon.ca/gp/product/B00213 ... UTF8&psc=1

Then a male to male HD Retrovision set of cables into my CRT component input.
Are you going into the advanced settings and switching it manually to YPbPr output?
strayan
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Re: GBS 8200/8220 CFW Project

Post by strayan »

Fluor wrote: HDMI from my RTX3080, to this HDMI to VGA: https://www.amazon.ca/gp/product/B07BN8 ... UTF8&psc=1
This is almost certainly the source of your woes. Try a HDMI to Component device like this https://www.amazon.com/gp/product/B01LZ73Y13/
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kitty666cats
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Re: GBS 8200/8220 CFW Project

Post by kitty666cats »

strayan wrote:
Fluor wrote: HDMI from my RTX3080, to this HDMI to VGA: https://www.amazon.ca/gp/product/B07BN8 ... UTF8&psc=1
This is almost certainly the source of your woes. Try a HDMI to Component device like this https://www.amazon.com/gp/product/B01LZ73Y13/
I would say avoid that model... unless you’ve personally tested it! The black metal box units with the slightly rounded tops seem to be the best of the cheap HDMI>YPbPr units :)

Also yeah, HDMI to VGAs with external PSUs tend to be more reliable, such as the Portta one. If you have an Extron RGB interface, it’s more ideal to send RGBS into a GBS versus RGBHV
MasoElCaveman
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Re: GBS 8200/8220 CFW Project

Post by MasoElCaveman »

I have an OSSC, but am somewhat distracted by the bob deinterlacing of 480i content from the ps2 so I really want compare motion adaptive deinterlacing and just ordered my gbs 8200 pre-made from https://www.tindie.com/products/chipnet ... converter/

However I intend to use a VGA to Component cable for the output, but I'm a little confused and if someone could clear this up for me that would be amazing. On resistor R26 I've seen I should replace that with a 110ohm resistor so Component output will look it's best right? Though that will make VGA output no longer a choice; which I'm fine with.

My last 2 questions are, does that mean on the software side of things with GBS Control I will always choose YPbPr instead of RGBHV? I see that it says compatibility is spotty through YPbPr, so would that mean I'll run into issues instead of just using VGA out and selecting RGBHV and not modding in the new resistor?

I want to run Component out because I wanted to connect it to my OSSC through component rather than VGA and line double 480p with the OSSC when it gets deinterlaced using motion adaptive from GBS Control. I'd like to keep my Dreamcast permanently plugged into the OSSC's VGA port, the PS2 into it's Component, and all other consoles switch between Scart because imo it's the easiest and quickest to plug in when needed.
Fluor
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Re: GBS 8200/8220 CFW Project

Post by Fluor »

kitty666cats wrote: Are you going into the advanced settings and switching it manually to YPbPr output?
Yes, at first I wasn't, but even that video that I mad already had this activated.

I ordered that rounded on top HDMI to YPbPr adapter and another HDMI to Composite to test. I really want to find an easy way to connect PC to 240p/15khz that most people could use without having to be too tech savy.
kvadevack
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Re: GBS 8200/8220 CFW Project

Post by kvadevack »

What VGA to HDMI adapters are you guys using and recommend? The two Chinese-brand adapters I've tried (one being the Foinnex plug-style one recommended by RetroRGB Bob, the other being a box I bought from a local retailer) both produce crackling and "chirping" audio when fed to my Blackmagic capture card (one more so than the other). It's not audible in stereo, but down-mixing to mono reveals the issue. I've also tried with my Extron RGB HDMI 300A, and it doesn't do this, so there has to be something about these adapters that the capture process doesn't like. I've tried messing around with sample rates and nothing.
leonk
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Re: GBS 8200/8220 CFW Project

Post by leonk »

I own 2 X68000 computers which I plan on using GBS-Control with. Most games are 31khz (480p) so it just pass-through the signal to the PC monitor. Some games are 15khz (240p) and then I rely on the scalling.

The device works well with my X68000 XVI compact, but fails with the original X68000 full tower. When it pass-thru mode, the LCD screen remains off. In 15khz games, the LCD screen says "unsupported resolution". When I force it to 480p, the screen shows the game but scrolls up fast for a few seconds, and then a "reset" is triggered, and it's back to "pass through".

I can do testing/captures of logs and post it here. For example, here's a recent capture:

h: 212 v: 318 PLL:0 A:7b7b7b S:02.18.20 I:00 D:0026 m:0 ht:1023 vt: 0 hpw: 0 u: 0 s: 0 S:12 W:-51
h: 213 v: 318 PLL:0 A:7b7b7b S:02.18.20 I:00 D:0026 m:0 ht:1023 vt: 0 hpw: 0 u: 0 s: 0 S:12 W:-51
h: 212 v: 318 PLL:0 A:7b7b7b S:02.18.20 I:00 D:0026 m:0 ht:1023 vt: 0 hpw: 0 u: 0 s: 0 S:12 W:-51
h: 213 v: 318 PLL:0 A:7b7b7b S:02.18.20 I:00 D:0026 m:0 ht:1023 vt: 0 hpw: 0 u: 0 s: 0 S:12 W:-51

Not sure what all this means, but willing to work with the devs to get this fixed.

Thanks.
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Re: GBS 8200/8220 CFW Project

Post by leonk »

I can confirm now on 2 different OG X68000 computers, the behaviour is identical. So it's something with the GBS not able to sync to the video levels of the computer?
strayan
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Re: GBS 8200/8220 CFW Project

Post by strayan »

Are there variations on the pinouts of different X68000 models?
leonk
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Re: GBS 8200/8220 CFW Project

Post by leonk »

strayan wrote:Are there variations on the pinouts of different X68000 models?
No. Pinout is identical. I use the same cable between all the computers. I can feed directly the 31k image to the LCD monitor and it shows up just fine. In pass-thru mode, the monitor is blinking like there is no signal.

I want the GBS-Control mostly to upscale the 240p games as my monitor doesn't support 240p.
leonk
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Re: GBS 8200/8220 CFW Project

Post by leonk »

Come to think of it, this reminded me that I did take oscilloscope readings a few years ago between the X68K that works and the one that for some reason doesn't work:

Original X68K: (Doesn't work with GBS-Control on VGA input plug)
- R/G/B all about 1.3-1.5Vpp
- hv sync 31k freq - 5.7Vpp

Compact Red Zone: (Does work with GBS-Control on VGA input plug)
- R/G/B all measured at about 1.6Vpp
- hv sync 31k freq - 2.64Vpp

I'm thinking the signal is too hot!
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maxtherabbit
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Re: GBS 8200/8220 CFW Project

Post by maxtherabbit »

GBS is designed for 3.3V LVTTL syncs, so that checks out
leonk
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Re: GBS 8200/8220 CFW Project

Post by leonk »

maxtherabbit wrote:GBS is designed for 3.3V LVTTL syncs, so that checks out
R22 and R33 setup a voltage divider for vertical sync. R22=1K, R33=10K. Assuming I'm connecting standard VGA PC to GBS, the voltage divider will result in 4.5V going to the GBS. As for horizontal sync (which seems to be tied to csync) there is no voltage divider.. just a 1K resistor at R34 to ground (1K terminated??) so the full 5V from VGA goes right into the device!?

What am I missing?
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maxtherabbit
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Re: GBS 8200/8220 CFW Project

Post by maxtherabbit »

You're not missing anything it's just bad design. What I should have said is the Tvia chip is designed for 3.3V syncs. I've tested it with 5V TTL sync input and it works, but if your X68k is going past 5V it doesn't surprise me that it stops working
leonk
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Re: GBS 8200/8220 CFW Project

Post by leonk »

Here’s more info on the sync coming out of an original X68000 computer.

vertical sync:

55hz frequency just a bit over 5Vpp

Image

horizontal sync:

31khz and 2Vpp

Image

So which of these is throwing off the GBS?
I know it can support the resolution but I think sync is off.
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maxtherabbit
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Re: GBS 8200/8220 CFW Project

Post by maxtherabbit »

Are you sure it supports 55Hz vertical refresh?

I'd try dropping the v-sync amplitude down a bit if you can
Last edited by maxtherabbit on Mon Oct 19, 2020 5:32 pm, edited 1 time in total.
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Syntax
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Re: GBS 8200/8220 CFW Project

Post by Syntax »

Why is the wiki install guide for the clock generator missing the 1000pF cap on CLK0 pin2?

https://github.com/ramapcsx2/gbs-contro ... tall-notes
leonk
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Re: GBS 8200/8220 CFW Project

Post by leonk »

maxtherabbit wrote:Are you sure it supports 55Hz vertical refresh?

I'd try dropping the v-sync amplitude down a bit if you can
You mean the PC monitor? sure does. Here's the final result; I replaced R34 with 10K resistor. Measuring at input pins of TVIA 5725.

VS - 55Hz, 3.9Vpp
HS - 31.6kHz, 3.4Vpp

Using stock firmware, I get solid picture on the TV. With GBS-Control, the screen is black, then comes in, stays for 5 seconds, and goes black again (all in passthru). So GBS-Control is doing something with sync that the TV doesn't like which stock firmware does not.

So at this point I'm stuck as the issue is a GBS-Control software issue and not hardware as far as I can see.
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