GBS 8200/8220 CFW Project

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strayan
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Re: GBS 8200/8220 CFW Project

Post by strayan »

SCARTicus wrote:
Josh128 wrote:Thats a really cool addition! Thanks for your efforts!
Josh, when you did that lag test with your camera, did you test the 240p downscaling mode or just upscaling modes? I really want to use this to get 240p out of my Xbox and Dreamcast, but I'm crazy about input lag, especially for fighters.
Downscaling lag results: https://youtu.be/fmfR0XI5czI?t=875
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SCARTicus
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Re: GBS 8200/8220 CFW Project

Post by SCARTicus »

Josh128 wrote:Just the upscaling mode. I would have to imagine that downscaling should be no more latency intensive than upscaling though.
Old Leo Bodnar tests measure the downscaling lag at around 8ms, which is about twice as much lag as the same tests from the same time showed for upscaling. That's why I am curious as to what your camera test would show.
strayan wrote:
Downscaling lag results: https://youtu.be/fmfR0XI5czI?t=875
That test was done an entire year ago, and since ten much has happened on this project. More importantly, this is a different testing methodology than Josh128 uses, and reports different numbers.
strayan
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Re: GBS 8200/8220 CFW Project

Post by strayan »

SCARTicus wrote: That test was done an entire year ago, and since ten much has happened on this project.
It has?
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Josh128
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Re: GBS 8200/8220 CFW Project

Post by Josh128 »

I actually have a Time Sleuth and HDMI to component and HDMI to VGA converters now, when I have time I will see if I can test on my 36" SD Trin for you. I cant use the camera to test because the VGA monitor wont accept 240p from a downscale, so I'd need two SD sets side by side, which I dont currently have set up.

Bobs testing is showing ~8ms though, so I wouldnt expect much difference in the tests I will run.
USSCrazybat
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Re: GBS 8200/8220 CFW Project

Post by USSCrazybat »

Hi all, just completed the hardware step of my GBS-C build and things are going pretty nicely. This is my first real project involving precise soldering of any kind and it's been a real learning experience. However, I didn't expect to run into any problems during the software step - which I unfortunately have.

I have been unable to flash the firmware to either of my D1 mini ESP2866 boards, and I keep getting a "Timed out waiting for packet header" error. The gbs-c code has been verified, everything before the actual writing process has been done correctly. I'm wondering if it could be something as simple as the USB cable I'm connecting the ESP board with. If anyone could offer any advice it would be greatly appreciated!
TyMiles2012
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Re: GBS 8200/8220 CFW Project

Post by TyMiles2012 »

I have a question about this. I have a HCKJ 8200 V5.1 board that works with this firmware (It was prebuilt so it has all the recommended modifications on the board according to the github), and it has an extra spot to put in another VGA connector which I assume will allow dual output on the boards that already have two VGA outs. Would it be as simple as soldering on another connector or are there other modifications I should make for it to work properly?
naldin
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Re: GBS 8200/8220 CFW Project

Post by naldin »

Guile wrote:I have an HD Box Pro which apparently uses the same chip as the gbs-8200. On the original gbs mod github by dooklink it mentions possibly supporting it.

Does anyone know if it is possible to mod the HD Box to become a gbs control? Seeing as it's such a vast improvement it would be fun to have another.
I have the same board and tried used ESP8266 but doesn't work. I saw that this board have different mappings pins in MTV230M, the HD BOX Pro have:
Menu - Pin 25
Down - Pin 26
Up - Pin 27

I saw in picture below that GBS use pin 37, 35 and 34. I think that debug and P8 will have another pins. My question is the debug pin and P8 come from some TVIA pin?

Image
Guile
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Re: GBS 8200/8220 CFW Project

Post by Guile »

naldin wrote:
I have the same board and tried used ESP8266 but doesn't work. I saw that this board have different mappings pins in MTV230M, the HD BOX Pro have:
Menu - Pin 25
Down - Pin 26
Up - Pin 27

I saw in picture below that GBS use pin 37, 35 and 34. I think that debug and P8 will have another pins. My question is the debug pin and P8 come from some TVIA pin?
That's interesting, on my hd box pro the chip is MTV230GMV. Where did connect SDL and SCA? I see them on the board but I don't know if they work.

Did you disable the hd box somehow like the gbs needs the jumper? I don't see a similar spot on the hd box.

Don't you only need to connect the single debug pin from that chip to the esp8266?
shimian
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Re: GBS 8200/8220 CFW Project

Post by shimian »

I was curious if anyone in here was running a GBS-C with an OG Xbox 1.6 w/ Component cables? If so, can you comment whether or not 720p passthrough works.

There are a few open GitHub issues, but the project author says it works fine. One person had to resort to VGA/Hacked VGA bios, but others on Reddit have commented it works, but make no comment about 720p passthrough.

Just curious what others have seen?

Thanks!
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Greg2600
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Re: GBS 8200/8220 CFW Project

Post by Greg2600 »

Is there a checklist of mods to the GBS 8200 to get it to downscale a Dreamcast VGA to component video (240p)? I wanted the GBS-C AIO but no one has made any in North America since the original pre-orders.
Guile
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Re: GBS 8200/8220 CFW Project

Post by Guile »

Greg2600 wrote:Is there a checklist of mods to the GBS 8200 to get it to downscale a Dreamcast VGA to component video (240p)? I wanted the GBS-C AIO but no one has made any in North America since the original pre-orders.
You need to use RGBS input to downscale from the Dreamcast. I used an Extron rgb interface and then a transcoder to convert the RGBHV output to component.

The only mod you need to the base gbs-8200 is the standard gbs-control mod with the esp8266.

The Dreamcast 240p output was very nice but it is a pain to deal with RGBS conversion and converting the RGBHV output. It looks like the gbs-c can also output component on its own but I never tried that.
webhdx
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Re: GBS 8200/8220 CFW Project

Post by webhdx »

I ordered 5 "yellow buttons" 2017 GBS-8200 boards to add SCART input and HDMI output to them. I've modified the boards with:
- clock gen
- C11 replaced with 22uF
- 10uF 0805 SMD caps soldered in parallel to C23, C41, C42, C48
- removed RGB pots

3 out of 5 boards are noise free, the output is very nice. 2 other boards are having diagonal waves issue. I'm using the same power supply and the same parts for all boards. I checked all power lines on the oscilloscope and the voltages seem to be stable, at least nothing obviously bad happening to them.


Image


Do you have any recommended fixes for 2017 boards?
Guile
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Re: GBS 8200/8220 CFW Project

Post by Guile »

webhdx wrote:
3 out of 5 boards are noise free, the output is very nice. 2 other boards are having diagonal waves issue. I'm using the same power supply and the same parts for all boards. I checked all power lines on the oscilloscope and the voltages seem to be stable, at least nothing obviously bad happening to them.

Do you have any recommended fixes for 2017 boards?
You can try putting copper tape on the bottom of the board on the ram traces. I did that and it helped but I also had rolling diagonal wave noise interference. The only thing that totally eliminated it was using a component cat5 ethernet extender to shield the signal. If you have multiple boards I guess that's not the best solution but it might help.

Are you running the input through a switch or distribution amp? If I plugged the source in directly I had no noise. I think some of the gbs chips are very sensitive to power.
webhdx
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Re: GBS 8200/8220 CFW Project

Post by webhdx »

My signal chain is very simple: Dreamcast -> VGA BOX -> GBS RGBHV input -> VGA-HDMI adapter -> LG TV

It looks like the interference is probably caused by the HDMI adapter since Component output is crystal clear. Interesting since I'm pretty sure I found the same adapter which was shipped with GBS-C AIO. I will look for a different one.
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Greg2600
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Re: GBS 8200/8220 CFW Project

Post by Greg2600 »

Guile wrote:
Greg2600 wrote:Is there a checklist of mods to the GBS 8200 to get it to downscale a Dreamcast VGA to component video (240p)? I wanted the GBS-C AIO but no one has made any in North America since the original pre-orders.
You need to use RGBS input to downscale from the Dreamcast. I used an Extron rgb interface and then a transcoder to convert the RGBHV output to component.

The only mod you need to the base gbs-8200 is the standard gbs-control mod with the esp8266.

The Dreamcast 240p output was very nice but it is a pain to deal with RGBS conversion and converting the RGBHV output. It looks like the gbs-c can also output component on its own but I never tried that.
Really all that? I was told GBS-C AIO would downscale Dreamcast from VGA to Component without a problem.

Namely I wanted to know if this one would be sufficient.

https://www.tindie.com/products/chipnet ... -converter
Guile
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Re: GBS 8200/8220 CFW Project

Post by Guile »

Greg2600 wrote:
Really all that? I was told GBS-C AIO would downscale Dreamcast from VGA to Component without a problem.

Namely I wanted to know if this one would be sufficient.

https://www.tindie.com/products/chipnet ... -converter
It looks like gbs-c can output component so you need a vga to component breakout cable for the output. You do need RGBS for the Dreamcast input, otherwise the picture is garbled with RGBHV. You need a sync combiner or rgb interface to convert RGBHV to RGBS and then it will work fine.

The one you linked is a pre-built one so yes that will work as long as you input RGBS.
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NoAffinity
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Re: GBS 8200/8220 CFW Project

Post by NoAffinity »

Rgbs or component. It downscales component sources just fine, too.

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

Post by DogP »

Hey,

I've got a somewhat odd input I'm trying to get working with the GBS-8220... hoping maybe one of the devs is reading this and has an idea.

It's a Super Off Road arcade PCB, which several others have also noticed won't work with a stock Gonbes. I started to dig into it, and noticed that the frequencies are a bit high. The H-Sync is ~16.9 kHz and V-Sync is ~66 Hz. With the stock Gonbes, it's just completely blank with an occasional frame. I decided to try with gbs-control, and it's better (shows video), but unlocked and squiggly. Occasionally you can sorta make out what it's trying to show.

I think the gbs-control firmware knows it isn't syncing, since I have to manually select my preset for it to show video (other boards show video with no user intervention), and eventually it goes black and I have to reselect the preset for it to show again.

Does anyone know what I could tweak to try getting this to sync correctly? I quickly looked through the code, but it wasn't immediately clear what I'd change to widen its input frequency range, etc.

Image
Image
Image

Thanks,
DogP
naldin
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Re: GBS 8200/8220 CFW Project

Post by naldin »

Guile wrote:
naldin wrote:
I have the same board and tried used ESP8266 but doesn't work. I saw that this board have different mappings pins in MTV230M, the HD BOX Pro have:
Menu - Pin 25
Down - Pin 26
Up - Pin 27

I saw in picture below that GBS use pin 37, 35 and 34. I think that debug and P8 will have another pins. My question is the debug pin and P8 come from some TVIA pin?
That's interesting, on my hd box pro the chip is MTV230GMV. Where did connect SDL and SCA? I see them on the board but I don't know if they work.

Did you disable the hd box somehow like the gbs needs the jumper? I don't see a similar spot on the hd box.

Don't you only need to connect the single debug pin from that chip to the esp8266?
Yes my IC is MTV230GMV too. For SCL and SDA look the picture, SCL pin 1 and SDA pin 4. My problem is with disable and debug pins, I need someone that have a GBS to check if this pins go to TVIA IC and if yes, which pins.

Image
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Greg2600
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Re: GBS 8200/8220 CFW Project

Post by Greg2600 »

Guile wrote:
Greg2600 wrote:
Really all that? I was told GBS-C AIO would downscale Dreamcast from VGA to Component without a problem.

Namely I wanted to know if this one would be sufficient.

https://www.tindie.com/products/chipnet ... -converter
It looks like gbs-c can output component so you need a vga to component breakout cable for the output. You do need RGBS for the Dreamcast input, otherwise the picture is garbled with RGBHV. You need a sync combiner or rgb interface to convert RGBHV to RGBS and then it will work fine.

The one you linked is a pre-built one so yes that will work as long as you input RGBS.
Ooooohhhh. First off, I already have a component break-out adapter, yes. However, I don't have something to convert RGB modes. As I've said, I was under the impression that the GBS-C AIO did not require an conversion, so I guess I'm stuck waiting for someone in the USA to make them again, if ever.
Guile
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Re: GBS 8200/8220 CFW Project

Post by Guile »

Greg2600 wrote:
Ooooohhhh. First off, I already have a component break-out adapter, yes. However, I don't have something to convert RGB modes. As I've said, I was under the impression that the GBS-C AIO did not require an conversion, so I guess I'm stuck waiting for someone in the USA to make them again, if ever.
NoAffinity mentioned that it can downscale component so you could also get a vga to component transcoder to convert the Dreamcast output. Extron rgb interfaces are pretty cheap too and will get you RGBS.

You could always try to build your own gbs-control. I'm pretty bad at soldering and I managed to do it. The actual setup of the esp8266 chip is really easy, takes 5 minutes. You can also use dupont connectors and then you only need to solder 5 points on the board and none on the arduino.

The gbs-c is so useful I'm planning on making a second and maybe even a third one with the extra esp8266 chips I have.
sharak
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Re: GBS 8200/8220 CFW Project

Post by sharak »

Anyone in the EU make suitable acrylic housings for the main board? At the moment my setup is a bit of a mess, including bad soldering, but it somehow works. Had trouble with the arduino flashing and some of the fiddly solder, but low and behold, it looks amazing.

Image

Image

I am using it at 480p input through SLG3000 and output 720p with scanlines, it looks so good!
DogP
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Re: GBS 8200/8220 CFW Project

Post by DogP »

BTW, I just wanted to mention that I have tested this board on a regular CRT, and it works (with a color issue, which is why I wanted to troubleshoot on my bench) - and I've successfully used a LOT of other arcade PCBs with my GBS-8220.

So, I'm fairly certain either the TrueView 5725 chip can't handle this specific sync, or it's just out of range of the typical settings (e.g. it tries to auto-sync to NTSC 15.75 kHz settings) and could work with some minor manual tweaks. And others have also mentioned problems getting the GBS-8220 to work with this Super Off Road.

Does gbs-control have a debug mode where I can manually peek and poke the 5725's registers?

Image

Thanks,
DogP
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Josh128
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Re: GBS 8200/8220 CFW Project

Post by Josh128 »

There is a debug mode but Im not sure what all you can do with it. Its an easy build, and cheap. Give it a try.
DogP
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Re: GBS 8200/8220 CFW Project

Post by DogP »

Josh128 wrote:There is a debug mode but Im not sure what all you can do with it. Its an easy build, and cheap. Give it a try.
Yeah, I've already built it and have it working... but "out of the box" it doesn't work with this PCB (7 posts up shows what I get: viewtopic.php?p=1464557&sid=a6c30007ed3 ... c#p1464557 ).

From what I could tell with debug mode, it outputs a bunch of debug messages and has another page of controls. But none of the controls seem to make a difference, and I didn't see any explicit read/write register functionality. I'm thinking maybe I need to tweak some of the H/V period register values, and it'd be nice to read back some of the status bits to see what mode it's in, if it thinks timing is stable, etc. Or, maybe the PLL registers need to be tweaked, if it can't lock because it's expecting to lock to a 15.75 kHz input and actually getting 16.9 kHz.

Thanks,
DogP
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Chipnetics
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Re: GBS 8200/8220 CFW Project

Post by Chipnetics »

Hi everyone, Chipnetics here; the dude who has been selling pre-assembled units on Tindie.

I wanted to drop a note that I've starting selling a cleaner design that looks a little more polished. Pictures from Tindie below with link. Selling at same price as before.

This modified design includes:

[*]Rear facing VGA/DSUB input, so all your cabling can be run at the rear of unit. :D
[*]Recessed VGA to HDMI output, with onboard USB power supply. (Benefit of no dongle protruding out back) 8)

Also all units now come with the clockgen mod; it's been pretty rare people ever order without it. And all units are still shipping with Triad PSU.

Tindie: https://www.tindie.com/products/chipnet ... converter/

Thank you!!

Image

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strayan
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Re: GBS 8200/8220 CFW Project

Post by strayan »

Has anyone tried one of these for their GBSC output?

https://electron-shepherd.com/analog2hdmi/
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Josh128
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Re: GBS 8200/8220 CFW Project

Post by Josh128 »

strayan wrote:Has anyone tried one of these for their GBSC output?

https://electron-shepherd.com/analog2hdmi/
Wow, that looks very cool. I wouldnt mind trying to install one in my GBS-C. Being so small, I might actually have room for it.
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Josh128
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Re: GBS 8200/8220 CFW Project

Post by Josh128 »

Discovered some very strange behaviour regarding input lag and the GBS-Control. I thought I saw something strange when I was doing the photo tests I posted several pages back, and I actually re-tested today. The GBS-Control is capable of super low input lag whether upscaling or downscaling, but unless you have some way to measure it, what you get on any given power up on the unit can vary from .65ms to 17ms. Apparently this is some kind of bug, but its real. Check out my test below. Display chain used was TS>Portta DAC>GBS-C>Component Out to 15kHz SD Wega Trinitron.

Image
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Syntax
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Re: GBS 8200/8220 CFW Project

Post by Syntax »

Awesome find that would be sweet to get sorted but unless someone else takes up the reigns from where rama left It ain't gonna happen.
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