GBS 8200/8220 CFW Project

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maxtherabbit
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Re: GBS 8200/8220 CFW Project

Post by maxtherabbit »

rama wrote:.. Which is another reason I'd like to look into Component cables more.
I think they're quite a bit easier to DIY, with just 3 signals instead of 4.
It "just" needs to have CSync added onto the green line, where it would fall onto the blanking area anyway.
Something like a diode could be all that's required, maybe.

I can then modify the YUV input to treat the signal as RGsB, and we would additionally benefit from the nicer stock YUV signal path on each GBS.

Just an idea atm :p
sure, or just buy HDRV
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AndehX
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Re: GBS 8200/8220 CFW Project

Post by AndehX »

Quick question. I'm getting scrolling lines of interference on the 720p preset. If I load a different preset, and then load the 720p preset again, the interference disappears. Any ideas whats going on?
Iraito
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Re: GBS 8200/8220 CFW Project

Post by Iraito »

I checked the motherboard, it's different, to the point where i just went and opened the console end of the cable, for now at least i can get a clean picture like this.

https://imgur.com/a/HdV1P92

Opening it was actually really easy, it's just two covers kept in place by 4 plastic pins, but i can't find a diagram for the pins, from what i understand:

Orange = red
Green = green
Blue = blue
Black = ground
Red = audio
White = audio
Yellow = CSYNC
Brown = 5V
Gray = ?

How should i move the cables around ?

P.S: Somebody probably noticed a lot of noise in the previous upload, i had the framerate fixed at 60 in the source of OBS which generated a strange green noise, by setting it "same as source" i get no more noise, besides the dot crawl one obviously.
rama
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Re: GBS 8200/8220 CFW Project

Post by rama »

AndehX:
Best if you had a video. A line of interference could be just about anything :p

Iraito:
That cable just makes me sad :p
Currently there is a wire on pin 6 for Composite Video. Move that wire to pin 5 for Luma.
Image
Iraito
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Re: GBS 8200/8220 CFW Project

Post by Iraito »

DAMN!

The cable may be cheap (i don't even remember, it's a late 90's one) but the picture i'm getting now is insanely clean, is a more expensive cable really worth it ?

EDIT: I have the same issue on SNES\GC, can i just do the same thing there ?
Ryoandr
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Re: GBS 8200/8220 CFW Project

Post by Ryoandr »

you can on SNES since it has Y from svideo too, only NTSC SNES/SFC have csync, so it's a good compromise for euro snes.
You can't on GC since only euro GCs have RGB and no Svideo at all.
Iraito
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Re: GBS 8200/8220 CFW Project

Post by Iraito »

Well, i have a super famicom\PAL snes and a PAL GC so i should be fine then.
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maxtherabbit
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Re: GBS 8200/8220 CFW Project

Post by maxtherabbit »

Iraito wrote: is a more expensive cable really worth it ?
yes, but maybe ignorance is bliss :mrgreen:
Iraito
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Re: GBS 8200/8220 CFW Project

Post by Iraito »

maxtherabbit wrote:
Iraito wrote: is a more expensive cable really worth it ?
yes, but maybe ignorance is bliss :mrgreen:
Or maybe there's a point where more expensive ≠ better, it's literally emulation quality, unless the more expensive cables can give me a blowjob i find really hard to believe spending more it's worth it.
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maxtherabbit
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Re: GBS 8200/8220 CFW Project

Post by maxtherabbit »

Iraito wrote:
maxtherabbit wrote:
Iraito wrote: is a more expensive cable really worth it ?
yes, but maybe ignorance is bliss :mrgreen:
Or maybe there's a point where more expensive ≠ better, it's literally emulation quality, unless the more expensive cables can give me a blowjob i find really hard to believe spending more it's worth it.
expensive does not equal better, but 75 ohm coax does in fact equal better

no offense but the cable you have is literally the worst possible quality tier of A/V cable, I promise you there's room for improvement
Iraito
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Re: GBS 8200/8220 CFW Project

Post by Iraito »

No offense at all i use cheap cable consciously, but to be honest, how much room for improvement is there ? i emulated a lot in the past using edgbla plug-in and it looks identical, if i never emulated in the past i could understand not knowing better but i used them all and i truly ask myself if there's a placebo effect in place regarding cables in the retro community.
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AtariBits
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Re: GBS 8200/8220 CFW Project

Post by AtariBits »

I thought I'd hop back in here now that its gotten a bit quieter, and tell you more about my new project, thanks to rama's help at getting me unstuck on my earlier software efforts,

A test board is on its way to me that will allow up to 4 preset tables to be chosen via a small dip switch. The board is based on a PIC12F1572, which is an 8-pin device, so the overall board size is very tiny. Its designed to plug into the I2C header on either a GBS-8200 or the GBS-8220. Of course the GBS-8200 will require the installation and soldering of a 4-pin male header to give you something to plug into.

There will be two boards created as part of this project, with the first one being a stand alone device called the GBS-PGM (see images below). The 2nd will be based on the same chip and firmware, but be developed as a carrier board for the GBS-8200 to mount into a custom Atari 8-bit alternative motherboard. Full source code in Great Cow Basic has also been released, making it easy for someone to use whatever collection of 4 preset tables they wish by modification of the GCB source, and then recompiling. Now this isn't meant to be a better solution to rama's Wi-Fi based application, and in fact its definitely not. But for situations where you are only going to use the GBS with a single known system, it does offer a very inexpensive and simple solution..

Board Top
Image

Board Bottom
Image

Schematic
Image

The JOY2PIC Programmer mentioned in the schematic is an Atari specific device for flashing PIC chips. However the ICSP header is in a standard PICkit2-3 format and will also work with either one of those programmers.

If anyone is interested in more details about this project, and/or the source code and firmware hex file, head on over to AtariAge and check out this Topic... RGB2VGA: customizing a GBS-8200 for a cleaner low-lag image

I go by the name MYTEK on the AtariAge forums, and also have a website where this stuff will eventually be posted at.
Michael from AtariBits
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NoAffinity
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Re: GBS 8200/8220 CFW Project

Post by NoAffinity »

Continuing to follow this great project in the background, over here. Updating my GBS board every so often, most recently last weekend. My OSSC died after a year of ownership, earlier this week. Been trying various chains of equipment to get my arcade cabinet stream looking nearly as good, finally decided to try the GBS in the chain tonight. I've got a Tim Worthington AV Driver splitting RGBS off of the JAMMA cable, now taking that into GBS w/ CFW. 1280x1024 VGA output to a Retrotek VGACTV1, component output to a Magewell Pro capture card.
Spoiler
Image
Image
Image
Image
I will argue that the image is as good as the original AV Driver -> OSSC -> HDMI capture via Magewell Pro setup...possibly better. The colors just look great with minimal adjustment on the GBS chain. On the OSSC chain, I was futzing with individual color gains forever, just to get them looking decent. I could probably dial down the gain a few notcheson the GBS, but I am happy with the overall image this chain is producing.

Thank you and keep up the good work as always, rama!
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NoAffinity
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Re: GBS 8200/8220 CFW Project

Post by NoAffinity »

Hey guys, what is currently considered the best version of the GBS-8200 - the one with best chance to not have noise in the image once all mods are done, best output quality? I'm looking to get a second one.

Also, anybody know where to get the cable for P12, or a seller that provides the P12 cable when buying a GBS?
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Nuck-TH
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Re: GBS 8200/8220 CFW Project

Post by Nuck-TH »

NoAffinity wrote:Hey guys, what is currently considered the best version of the GBS-8200 - the one with best chance to not have noise in the image once all mods are done, best output quality? I'm looking to get a second one.
Complete lottery. I have 2 same boards - one has noise even with all modifications, other haven't any noise unmodified at all. Go figure...
NoAffinity wrote:Also, anybody know where to get the cable for P12, or a seller that provides the P12 cable when buying a GBS?
P12 is standart D-SUB vga connector. Maybe you mean P11 above it? That connector with wires come with boards usually.
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NoAffinity
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Re: GBS 8200/8220 CFW Project

Post by NoAffinity »

Maybe im referring to the wrong connector. Its right next to the d-sub vga output. Its an inline connector like the rgbs input but is parallel with the d-sub output. It is a 12-pin connector.

All pictures of gbs 8200s i see online show the 2 pin power and rgbs input connectors included, but no other connectors. I didnt get that connector with mine either.

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rama
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Re: GBS 8200/8220 CFW Project

Post by rama »

The best without much mod work is the most common "V4.0" design. Simply go by the black buttons.

But I like the GBS 8220 the best, once the output video buffer has its charge pump noise fixed.
I still have no idea why they choose the isl59830 for the job. It's an expensive part with the only real benefit going unused on the 8220.
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NoAffinity
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Re: GBS 8200/8220 CFW Project

Post by NoAffinity »

Thanks, guys. Will look for one with the black buttons.

hey rama - what is the pinout for ypbpr output?
rama
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Re: GBS 8200/8220 CFW Project

Post by rama »

You probably want one of these, I guess:
Image

G = Y
B = Pb
R = Pr

(Oh, and thanks for all the kind words. I never know how to respond though :p)
Ryoandr
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Re: GBS 8200/8220 CFW Project

Post by Ryoandr »

GBS worked a treat this weekend
https://streamable.com/fghai
Shiver_169
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Re: GBS 8200/8220 CFW Project

Post by Shiver_169 »

Hello guys.

For some time now I have been following the project through the various mods to the GBS8200, which due to my poor ability with the soldering iron has caused the premature death of more than one PCB.

My last board died because I had many problems to connect the debbug pin correctly without it being prone to release constantly. My point with this is that while I have little experience with the welder I have always believed that welding directly on the legs of a component is quite messy, I wish there was a simpler welding point for this.

Now I have come back because I bought a new board and re-made the mod for GBS Control and everything went well, except that at first it did not detect the RGB signals that connected to it and I realized that this was because of the potentiometers it has The PCBs were right in the middle. I reduced them to the minimum possible and now it worked. Now when I connect my SNES Jr something weird happened, everything will look beautiful the 1080p preset on my Panasonic 4k TV but I notice a small movement that completely moves the screen shown from top to bottom only a little every so often, it is not so annoying to be unplayable but if it shows and after playing a little is tired, I guess it is because of the rare Framerate issue that the console is difficult to deal with even with the OSSC. But I don't know if anyone has noticed this problem and if so, how it has been solved. I could also try my Sega Saturn and this does not have this problem the image is solid and beautiful thanks to the scaling. Now another strange problem I have is with Dreamcast when trying to connect it by VGA to the GBS8200 through a generic VGA Box I notice that the VGA box does not even detect that it is connected I know it by a small LED that indicates the connection if it is connected directly by VGA. I don't know if this problem is also normal and there is some way to solve it. As always, thank you very much and I look forward to your support to continue improving this great project.
rama
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Re: GBS 8200/8220 CFW Project

Post by rama »

The debug pin connection isn't essential to operation. Gbscontrol will work without it.
I need this signal to adapt the output frequency to the input, so as to minimize the tear line problem that you seem to describe.

Here I have first bent my wire to form, then clamped it down with the green jumper.
I applied some solder to the pin and the wire, then connected the two by a brief touch with the iron only.
It's mechanically stable now, with the jumper making sure the wire never moves.
Maybe this helps :)
Spoiler
Image
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NoAffinity
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Re: GBS 8200/8220 CFW Project

Post by NoAffinity »

rama wrote:You probably want one of these, I guess:
Image

G = Y
B = Pb
R = Pr

(Oh, and thanks for all the kind words. I never know how to respond though :p)
Well, isn't that just fantastic! Just so happens...

https://youtu.be/fAtS0yR7unE

Just eliminated the VGA->YPbPr converter from the chain. :D
Iraito
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Re: GBS 8200/8220 CFW Project

Post by Iraito »

So i was experimenting With GBI interface for my gameboy player:

GBI standard works perfectly but it's 480p and kinda soft

GBI speedrun Looks really crisp but the picture is jumpy

GBI HD It's crispy too but still kinda jumpy

So i tried the versions designed for OSSC and framemeister:

GBI speedrun-OSSC it's less unstable

GBI HD-OSSC give me a totally garbled picture

GBI HD-framemeister Looks like the best one and also the most stable, for some reason it also cleaned up at least 80% of the dot crawl issue

What's the best setup to use ? has the GBI been tested before ?
Shiver_169
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Re: GBS 8200/8220 CFW Project

Post by Shiver_169 »

rama wrote:The debug pin connection isn't essential to operation. Gbscontrol will work without it.
I need this signal to adapt the output frequency to the input, so as to minimize the tear line problem that you seem to describe.

Here I have first bent my wire to form, then clamped it down with the green jumper.
I applied some solder to the pin and the wire, then connected the two by a brief touch with the iron only.
It's mechanically stable now, with the jumper making sure the wire never moves.
Maybe this helps :)
Spoiler
Image
Really, thank you very much Rama, seems much more stable to weld the cable so instead of using the vertical welding versions I had seen it was the most popular around here. I will try to avoid problems in the future.

Now you know something about my problem with SNES Jr I don't know if it's normal because of its weird framerate or it's a problem they're still working on or if it's something from my GBS 8200 that, as rare as it may seem this time, I got a V4 of Black buttons but claims to be manufactured this year shows April 2019 I was curious although I do not know if more problems or less than other PCBs. I hope we can clarify to continue discarding things. Since for example I realize that I have always connected the ESP8266 to the 3.3V outputs of the GBS8200 and reviewing the wiki in detail I see that it is not the most advisable so I will rearrange my cables to see if this improves the stability of the signal with SNES above all. Greetings and I'm still waiting for your answers.
benryves
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Re: GBS 8200/8220 CFW Project

Post by benryves »

Shiver_169 wrote:My last board died because I had many problems to connect the debbug pin correctly without it being prone to release constantly. My point with this is that while I have little experience with the welder I have always believed that welding directly on the legs of a component is quite messy, I wish there was a simpler welding point for this.
I used a chip socket and soldered the wires to that, it can then be pushed onto the chip upside down.
Shiver_169 wrote:I notice a small movement that completely moves the screen shown from top to bottom only a little every so often, it is not so annoying to be unplayable but if it shows and after playing a little is tired, I guess it is because of the rare Framerate issue that the console is difficult to deal with even with the OSSC. But I don't know if anyone has noticed this problem and if so, how it has been solved.
I have the same issue on my TV, I think this is due to the Active Frametime Lock feature which (as far as I can tell) occasionally adjusts the number of scanlines in the vertical blank period to keep the output frame rate in sync with the input frame rate. On my TV this results in the picture moving up or down every so often, so I switch the Active Frametime Lock off (which instead produces a horizontal tear line that appears occasionally).
rama
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Re: GBS 8200/8220 CFW Project

Post by rama »

Yep, that can happen with the Frame Lock feature.
It works without image shift on my PC TFT, but not on the HDMI TV (via VGA > HDMI adapter).
If it shifts the image for you, better keep it off.
The drawback is an occasional moving line top to bottom or bottom to top, that can only be seen while the game scrolls.

On that note, I'm currently working on "un-hacking" Input Formatter details.
This is taking a lot of time and I hope it'll be worth it.
So far, it appears that I can reduce the tear line (making it thinner) and maybe get rid of all the green bar effects that can happen.
This totally changes assumptions I had in place since 2017, so once this update is out, please report any new effects you notice.
And please be patient then while I fix them ;p

(For the technically minded: Previously, I set up Input Formatter blanking areas to start at 0 and reach out a little from there. The more correct way is to start blanking at the end of active video, cross the 0 border, and reach out a little more. This new approach means changing 4 different IF parameters that interact in weird ways. I hope I can figure it all out!)
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NoAffinity
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Re: GBS 8200/8220 CFW Project

Post by NoAffinity »

Rama - excited to see this new development! :)

Shiver_169 - you can wire power for the esp off of the power supply input (solder side of the gbs board) and use a 5v power supply to power both the gbs and the esp in parallel. Just dont ever plug a psu >5v in. It wont end well. ;)

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Syntax
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Re: GBS 8200/8220 CFW Project

Post by Syntax »

I've just been powering the whole system in parallel via the Wemos D1 mini usb port with a 2A usb charger.
This way I always have a usb cable plugged into the Wemos ready for updates. I have heaps of spare 2A Samsung/iPhone chargers for some reason.
rama
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Re: GBS 8200/8220 CFW Project

Post by rama »

I would just recommend to avoid passing all the system power through a micro USB connector.
A fully loaded GBS-8220 + ESP8266 averages about 0.8A @ 5V = 4W, which is borderline for many of today's cables and connectors.
If the connector adds enough resistance, the voltage into the GBS main converter will be too low at times, leading to somewhat random issues.

A barrel connector supply into the GBS + the bundled 2 wire power cable for the ESP8266 (into its 5V input) are ideal :)

NoAffinity:
Did you change the DAC current control resistor when switching to Component?
RGB requires the (stock) 150 Ohm resistor, Component requires ~110 Ohm.
If the resistor isn't changed, color mixing will be off and some setups don't recognize the sync pulse.

Iraito:
The GBI sounds like a cool test scenario. Unfortunately, I don't have one to try it out.
If I knew what the incompatible modes do exactly, I could try and figure out something to make them stable.
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