GBS 8200/8220 CFW Project

The place for all discussion on gaming hardware
User avatar
NoAffinity
Posts: 1018
Joined: Mon May 07, 2018 5:27 pm
Location: Escondido, CA, USA

Re: GBS 8200/8220 CFW Project

Post by NoAffinity »

Lack of SFC sync could be due to jitter. Is your sfc dejitter modded?

Sent from my SM-G955U using Tapatalk
airainchoc
Posts: 8
Joined: Thu Dec 29, 2022 12:02 am

Re: GBS 8200/8220 CFW Project

Post by airainchoc »

No, it's full stock, but works nicely on my RGB only crt
User avatar
NoAffinity
Posts: 1018
Joined: Mon May 07, 2018 5:27 pm
Location: Escondido, CA, USA

Re: GBS 8200/8220 CFW Project

Post by NoAffinity »

Crt's are forgiving of the sync jitter. Scalers/multipliers are not.

Sent from my SM-G955U using Tapatalk
User avatar
RuffNEC
Posts: 264
Joined: Thu Jul 21, 2005 11:23 am

Re: GBS 8200/8220 CFW Project

Post by RuffNEC »

Doesn't the GBS-C support 1080i for example PS2?

Id like to boot them in 480p/1080p but most games don't support it with out enabling "skip video fix" which is a very hgih trade off in story games.
User avatar
NoAffinity
Posts: 1018
Joined: Mon May 07, 2018 5:27 pm
Location: Escondido, CA, USA

Re: GBS 8200/8220 CFW Project

Post by NoAffinity »

RuffNEC wrote:Doesn't the GBS-C support 1080i for example PS2?

Id like to boot them in 480p/1080p but most games don't support it with out enabling "skip video fix" which is a very hgih trade off in story games.
It will deinterlace 1080i, and seemingly downcales to 540p? The GBS-C automatically goes to pass-thru...at least on the rama final firmware and UI. Attempting to change to any other profile results in it defaulting to pass thru.

Tested with x360 HDMI out->HDMI splitter
->HDMI-to-VGA adapter->GBS-C VGA input
->TCL 49s405 HDMI input

GBS-C output->Sun Micorsystems GDM-5410 that will not accept interlaced signals of any type. The scanlines visible on-screen (and in the below picture, more prevalent at the top of the screen in the photo) are consistent with how it handles lower resolutions, and the GDM-5410's OSD reports it is receiving a 33.7kHZ/60Hz signal.

The TCL screen confirms it is receiving a 1080i signal direct from x360, as seen below.
Spoiler
Image
Image
Image
I also did a sanity check by feeding the GBS-C output to OSSC and the OSSC reports that it is receiving a 562-p, 33.7kHz/59.82Hz signal.

Anybody else want to double check these results against their own?

:edit: for an additional sanity check, I fed my GBS-C some 480i from PS2. With this signal input, all profiles are selectable and the OSSC receiving the GBS-C VGA output confirms the change in output resolution per the selected profile.

:edit edit: Did some additional testing with xbox original ypbpr output. Turns out I own 2 of the 1080i titles - Dragon's Lair 3D and Atari Anthology.

The chain in this scenario is:
Xbox ybppr -> GBS-C -> VGA Matrix
->OSSC -> TCL 49s405 HDMI input
->GDM-5410 VGA input

The GBS-C behavior is the same, on the surface - deafaults to pass-through mode, cannot be changed to any other profile.

The OSSC reports it is receiving a 1125-i, 33.7kHz/60Hz signal. With OSSC set to passthru for 1080i signals, the TCL reports it is receiving a 1080i signal; with OSSC set to line2x (bob) for 1080i signals, the TCL reports it is receiving a 1080p signal.

The GDM-5410 is also receiving and resolving the GBS-C output. There is a little bit of image flicker noticeable if getting very close to the screen, but the scanlines are still there as if it is a lower resolution input; it is not displaying an interlaced image. GDM-5410's OSD reports that it is receiving a 33.8kHz/60Hz signal. The fact that the GDM is able to resolve this signal is a very interesting aside, but not really germaine to the point of these test.
Spoiler
Image
Image
Image

GDM-5410 - best granularity I can get with my phone camera
Image
I think the truly interesting thing here, and not sure that this has been discussed previously, is that a 1080i signal input through GBS-C's VGA input will be deinterlaced and downscaled to (seemingly) 540p. Again, would like some additional checks/testing by others to validate.
User avatar
NoAffinity
Posts: 1018
Joined: Mon May 07, 2018 5:27 pm
Location: Escondido, CA, USA

Re: GBS 8200/8220 CFW Project

Post by NoAffinity »

Continued with some more testing of this. I have been unable to replicate 540p output (1080i deinterlaced and downscaled) from gbs-c. I tested some more with x360 and also with ps3 - hdmi output from both, with the chain as noted above.

X360 1080i hdmi output is being passed through at 1080i.

Ps3 1080i hdmi output is also being passed through at 1080i.

Xbox og 1080i ypbpr output is being tranacoded and output at 1080i

This is interesting because earlier discussions seemed to agree that the gbs is not able to output interlaced signals.

Sent from my SM-G955U using Tapatalk
User avatar
RuffNEC
Posts: 264
Joined: Thu Jul 21, 2005 11:23 am

Re: GBS 8200/8220 CFW Project

Post by RuffNEC »

thx for testing, I wasn't able to sync with my monitor but maybe different If I put a OSSC in between
User avatar
KnightNZ
Posts: 9
Joined: Fri Apr 14, 2023 12:45 am
Contact:

Re: GBS 8200/8220 CFW Project

Post by KnightNZ »

Apologies if this is the wrong place to ask, but I see quite a lot of commits on the gbscontrol project page on GitHub. Does anyone know if anything has changed of any real merit in the past year or so that'd be worthwhile trying an upgrade with on my DIY'd GBS-C?

Thanks!
User avatar
Kez
Posts: 818
Joined: Thu Jul 20, 2017 7:09 am

Re: GBS 8200/8220 CFW Project

Post by Kez »

The big one that was fixed fairly recently is the occasional screen tear you get with the clockgen. So like every once in a while you get a weird tear that persists on the screen for some time. If you've had that issue then it may be worth updating.
User avatar
Trevor spencer
Posts: 1032
Joined: Sat Jan 29, 2005 1:17 pm
Location: UK
Contact:

Re: GBS 8200/8220 CFW Project

Post by Trevor spencer »

Hi

I looked into making one of these in the past and kinda got lost as there seemed to be various guides that used different parts and got a bit confussed with it all.

Does anyone have a decent guide to follow with a parts list ? Also where is the best place to buy the GBS ?

Thanks :)
Check out my YouTube Channel
YouTube
User avatar
NoAffinity
Posts: 1018
Joined: Mon May 07, 2018 5:27 pm
Location: Escondido, CA, USA

Re: GBS 8200/8220 CFW Project

Post by NoAffinity »

Trevor spencer wrote:Hi

I looked into making one of these in the past and kinda got lost as there seemed to be various guides that used different parts and got a bit confussed with it all.

Does anyone have a decent guide to follow with a parts list ? Also where is the best place to buy the GBS ?

Thanks :)
The mods are on rama's github. Do all of the required mods for whichever model you're working with - 8200 or 8220. If you spend a few minutes reading and digesting the info, it's pretty straight forward.

Sent from my SM-G955U using Tapatalk
User avatar
Trevor spencer
Posts: 1032
Joined: Sat Jan 29, 2005 1:17 pm
Location: UK
Contact:

Re: GBS 8200/8220 CFW Project

Post by Trevor spencer »

OK great , thanks.

I'll concentrate on that one then.
Check out my YouTube Channel
YouTube
User avatar
Josh128
Posts: 2123
Joined: Thu Jan 16, 2014 9:01 am

Re: GBS 8200/8220 CFW Project

Post by Josh128 »

1080i or 540p output (or both) would be a fantastic option for those wanting to get the lowest possible lag on Sony HD CRTs. I asked Rama a while back if it would be possible and he said yes, the chipset should be capable of it but he didnt have the time to implement it, which I can understand....which reminds me that Mike Chi is such a cool dude as he implemented it to one of the RT5X FW's with just a few requests on this forum, and it worked great.
Naudriel
Posts: 3
Joined: Tue Dec 01, 2020 7:45 pm

Re: GBS 8200/8220 CFW Project

Post by Naudriel »

Hey, guys!

Got myself a McBazel ODV GBS-C (https://www.odv-gbsc.com/) and, while it works fine, I can't for the life of me figure out how to properly update the firmware.

I have Arduino IDE installed and the sketch prepared but the ODV device does not connect to my PC. I have plugged it via USB, pressed and held the control knob, then powered on the device. But the PC doesn't see the board.

Maybe someone here also has the same model and I'm just not understanding the instructions correctly or mine's micro usb port is busted.
User avatar
NoAffinity
Posts: 1018
Joined: Mon May 07, 2018 5:27 pm
Location: Escondido, CA, USA

Re: GBS 8200/8220 CFW Project

Post by NoAffinity »

Did you install the driver for the eps?

https://tttapa.github.io/ESP8266/Chap03 ... tware.html

Sent from my SM-G955U using Tapatalk
Naudriel
Posts: 3
Joined: Tue Dec 01, 2020 7:45 pm

Re: GBS 8200/8220 CFW Project

Post by Naudriel »

Yes, of course. Reinstalled them again, but still nothing. and their support is not very helpful.

What gives me hope is that if the USB didn't work at all, they wouldn't have been able to flash the current firmware.
fiftythree33
Posts: 4
Joined: Wed Mar 15, 2023 12:00 am

Re: GBS 8200/8220 CFW Project

Post by fiftythree33 »

Gunstar wrote:
fiftythree33 wrote:Can anyone help out with this issue? Think it got lost in the post approval shuffle...
You should be getting the same message as below even without a source plugged in if I'm understanding you correctly. I could be wrong but I don't think the clock gen mod is working
Image
Thank you for replying Gunstar!! I missed it due to starting a new page... Confused as to what I'm doing wrong but very thankful to see your screenshot!

I'll grab another clock and esp board to be sure...
thchardcore
Posts: 481
Joined: Wed Jun 22, 2005 9:20 am
Location: Liberal cesspool

Re: GBS 8200/8220 CFW Project

Post by thchardcore »

Any way for me to force 640x480 output? I am using a PCB that outputs this when used with any other line doubler but I only 720x480 with the GBSC.
A camel is a horse designed by a committee
User avatar
NoAffinity
Posts: 1018
Joined: Mon May 07, 2018 5:27 pm
Location: Escondido, CA, USA

Re: GBS 8200/8220 CFW Project

Post by NoAffinity »

thchardcore wrote:Any way for me to force 640x480 output? I am using a PCB that outputs this when used with any other line doubler but I only 720x480 with the GBSC.
Maybe by modifying the cfw code. Otherwise, no.

Sent from my SM-G955U using Tapatalk
thchardcore
Posts: 481
Joined: Wed Jun 22, 2005 9:20 am
Location: Liberal cesspool

Re: GBS 8200/8220 CFW Project

Post by thchardcore »

Thanks. Need a 4:3 output to PC CRT, so this won't work then.
A camel is a horse designed by a committee
User avatar
NoAffinity
Posts: 1018
Joined: Mon May 07, 2018 5:27 pm
Location: Escondido, CA, USA

Re: GBS 8200/8220 CFW Project

Post by NoAffinity »

The 1280x960 profile is 4:3

Sent from my SM-G955U using Tapatalk
User avatar
maxtherabbit
Posts: 1763
Joined: Mon Mar 05, 2018 4:03 pm

Re: GBS 8200/8220 CFW Project

Post by maxtherabbit »

thchardcore wrote:Thanks. Need a 4:3 output to PC CRT, so this won't work then.
just use the 720x480 preset and adjust the monitors' horizontal size to fit, boom 4:3
4642702342
Posts: 1
Joined: Sun Apr 30, 2023 4:39 am

Re: GBS 8200/8220 CFW Project

Post by 4642702342 »

Hello, I just start using gsb-control, but it seems like it displays scanline wrong.
some lines that suppose to be complete black didn't go entirely black.

I tried to set both "MADPT_VIIR_COEF" and "MADPT_Y_MI_OFFSET" to zero, but it didn't help

Is it a hardware issue, or it's a software issue?
Freedy
Posts: 22
Joined: Wed Jul 31, 2019 8:56 am

Re: GBS 8200/8220 CFW Project

Post by Freedy »

hi,
I have a GBS-C with external clock gen, latest firmware, I soldered in the extra 10uF parallel capacitors.
I like how it upscales, but I have really washed out colors with ps2 via component. (in the future I plan to install a scart input, too)
I tried messing around in the GBS-C settings, but no luck.
Other interesting thing is, sometimes some noise appears on the whole screen, "waves moving diagonally". Some restarts / resets solve it.

Do you have some tips what to check / how to set it up, to get a less washed out picture?

Sorry if it is already explained, but I did not find search I can use inside this topic, for some reason I only can search in every "Hardware" subtopics at once.
User avatar
NoAffinity
Posts: 1018
Joined: Mon May 07, 2018 5:27 pm
Location: Escondido, CA, USA

Re: GBS 8200/8220 CFW Project

Post by NoAffinity »

^you should do all the recommended mods.

That aside...

Check your monitor/screen. It should be set for full color range. Check its manual, for how to verify/set this. Some call it "native". Dont trust "auto" or "compatibility".

Also check that the output in gbs control UI is not set to ypbpr if you are outputting vga.

However, I wouldnt expect the cause that either of these recommendations will fix would affect only one console and not others. Have you tested with other component consoles?

Make sure auto gain is set to "on" in the gbs control UI also. It takes a few minutes of sampling to normlaize, and helps if it gets exposed to a black screen and white screen.

As for noise, some gbs units are noisier than others. If it is only occurring with some consoles, its probably cheap cables that is/are causing the issues. You can always try the copper tape trick. https://youtu.be/p2Hd0KO28FU

Sent from my SM-G955U using Tapatalk
thchardcore
Posts: 481
Joined: Wed Jun 22, 2005 9:20 am
Location: Liberal cesspool

Re: GBS 8200/8220 CFW Project

Post by thchardcore »

maxtherabbit wrote:
thchardcore wrote:Thanks. Need a 4:3 output to PC CRT, so this won't work then.
just use the 720x480 preset and adjust the monitors' horizontal size to fit, boom 4:3
It is at max width but it is still too small. :(

640x480 seems like a no brainer here, not sure why it was removed at some point.
Last edited by thchardcore on Wed May 03, 2023 5:19 am, edited 1 time in total.
A camel is a horse designed by a committee
Freedy
Posts: 22
Joined: Wed Jul 31, 2019 8:56 am

Re: GBS 8200/8220 CFW Project

Post by Freedy »

NoAffinity wrote:^you should do all the recommended mods.

That aside...

Check your monitor/screen. It should be set for full color range. Check its manual, for how to verify/set this. Some call it "native". Dont trust "auto" or "compatibility".

Also check that the output in gbs control UI is not set to ypbpr if you are outputting vga.

However, I wouldnt expect the cause that either of these recommendations will fix would affect only one console and not others. Have you tested with other component consoles?

Make sure auto gain is set to "on" in the gbs control UI also. It takes a few minutes of sampling to normlaize, and helps if it gets exposed to a black screen and white screen.

As for noise, some gbs units are noisier than others. If it is only occurring with some consoles, its probably cheap cables that is/are causing the issues. You can always try the copper tape trick. https://youtu.be/p2Hd0KO28FU

Sent from my SM-G955U using Tapatalk
Thank you very much! I checked hdmi settings on my tv, and turned on “extended mode” or something similar, and changed the hdmi black level to auto from normal. Now the picture is much-much better! I wanted to find a problem with the gbs itself, didn’t think that I need to change something on the tv side.
Bassa-Bassa
Posts: 1159
Joined: Tue Mar 12, 2019 5:18 pm

Re: GBS 8200/8220 CFW Project

Post by Bassa-Bassa »

This thread really beats me with its length, hopefully you don't mind me asking things which likely have already been touched. I'm basically overwhelmed by the amount of available options just on ebay and Ali express. Are the ODV models sold from China reliable, anyone knows? Or is it that they always were from China?

The Bitfunx GBSC doesn't have SCART input nor an actual case, but it has a Saturn connector output and it's quite cheaper. Main purpose I want it for is downscaling to 240p for a consumer RGB TV, so I don't know against the former (or any other).

As a general rule for GBS-C devices, should I expect 5V/TTL output and c-sync input requirement?

Also, are "the recommended mods" listed anywhere?

Thanks!
User avatar
NoAffinity
Posts: 1018
Joined: Mon May 07, 2018 5:27 pm
Location: Escondido, CA, USA

Re: GBS 8200/8220 CFW Project

Post by NoAffinity »

The mods library can be found from rama's github.
https://ramapcsx2.github.io/gbs-control ... brary.html

I cant speak to any of the chinese variants. I'll let others chime in there. Note: downscaling does not work for vga input.

VGA output is .7vp-p. If you mod the gbs for ypbpr output, it will be 1vp-p output (or very close to it).




Sent from my SM-G955U using Tapatalk
Bassa-Bassa
Posts: 1159
Joined: Tue Mar 12, 2019 5:18 pm

Re: GBS 8200/8220 CFW Project

Post by Bassa-Bassa »

Thanks for the reply. The question now I guess for those who know is if these modern variants sold through ebay/Ali express will normally include some of those mods in the Rama Github page, as some even tell you the firmware is Rama-based. I mean, you at least would expect, for a device which got a SCART input and a Saturn connector as output, the electrical and sync specs are consumer-level, wouldn't you?

The downscaling not working for VGA sources is almost deal-breaker for me though, and it's not the first time I read about it. So what's the people dowscaling to 240p then (and reportedly getting good results)? 480i with its antiflicker filter?

Edit.- Is it a sync arrangement issue and you just meant that I need to transform RGBHV into an RGBS input beforehand?
Post Reply