shmups.system11.org

Hey, you got more than I did! That's not fair!

I, too, got the precious precioussss aluminum.

You can thank me for finding these disappointing $4 listings on eBay (incorrectly listed as 'GBS820') and sharing them in the CRT Discord, and you can thank Ryoandr (another CRT Discord-dawg) for sharing them here. With our forces combined, we hath wrought disappointment on ourselves and our fellow vidya nerds!

Best $4 I ever spent, man...

EDIT:

I didn't check my packing list, I wonder if mine also was declared as 'SHOOTING'. Yep, definitely some top notch bullet shells we all have. Let's all mail them to Analogue, they can make some more $2000 Nintendos with them!

I think the category on eBay was archery or something similar

Lol, so now that everyone has about 10 dozen aluminium shells.. What *are* they?
Any use for them? :p

We can all join forces and build the world's longest joystick

I've been wondering that myself since I got them.

I'm absolutely clueless so far.

rama: I'm not able to get pass through mode working at all with 400p/480p RGBHV sources. Tried 3 different digital displays they all say "invalid format" or "out of range" (but they sync to the signal if I plug them directly into the source.) I haven't thrown it on the scope yet, but you have any idea what's going on?

ramapcsx2 your work on the GBS-C is freaking fantastic!!!!
https://youtu.be/tIsAeTEaZQA

maxtherabbit:
Take a look at the preferences > low res: use upscaling.
Try toggling that.

amoore2600:
What an awesome video, thanks for that!
I didn't realize how comparable gbscontrol can be to the reference.

So yeah, gbscontrol is slightly more blurry, but not too much.
It passes the checkerboard light cone test in level 2, where non-enthusiast scalers always fail.
I knew from the beginning that it was all in the software

Overall, I never thought it could get this good

Just wanted to express my appreciation once again as well.
I don't know if you remember, but I was bugging you about my scaler losing sync every once in a while. Well after updating it turned out that my VGA to BNC cable or the BNC connector on the monitor didn't give a proper contact

I wiggled the sync connectors a bit and played an hour without any sync drops.

I'm not tracking - why would a scaling option affect pass through? Shouldn't pass through bypass scaling no matter what?

EDIT to add: toggling the "use upscaling" option did the trick, I guess that's the real way to turn pass through on and off?

Anyway back to my purpose in all this - 70Hz actually works fine in passthrough mode. If you try to scale it, it goes apeshit obviously but passthrough seems to work fine

There's probably a bug in the mode decision making code.
Rarely used modes don't mix well with the requirements some of the later additions have.
I'll fix all that stuff eventually :p

Some have asked for ways to support me with this project, so I finally managed to set something up.
So if you like gbscontrol, you can now buy me a coffee

https://www.buymeacoffee.com/ramapcsx2

Thank you!

Edit:
Seriously, thanks you guys

Just wanted to chime in and say that this is truly great work you do

Hello, gentlemen.
I hope this is the right place for this enquiry.

Before I try this improved firmware/mod, I wanted to make sure my GBS-8200 board itself works, and more specifically whether I can use it with my Model 2 Sega Mega Drive or not.

The latter is VA4 PAL MD2 board with a BH7326AF encoder chip and a region switch mod which works fine, but obviously loses all colour over composite output when switched to NTSC.
RGB would be a solution, but I want to connect to a VGA monitor, so here we are.

Unfortunately, the first try didn't go very well. Here's a video showing how the image jumps all over the place: https://drive.google.com/open?id=1Mt2m0 ... irdUS688u_
If I press the "Auto" button, the image stabilises for two or three seconds, then it's back to trampoline jumping.

Curiously, if I set the Vertical Position to anything less than 14 in the "Geometry" menu, I get this: https://drive.google.com/open?id=1MqyLb ... q-Dxsdt6vx

Even better, if I switch the input from RGBs to RGBHV I get "No Input" but then if I change the display resolution to anything else, I get a perfectly stable image but with wrong colours: https://drive.google.com/open?id=1MxKip ... IXg_CHwr4P
If I manually adjust the trim pots adding lots of green and removing a bit of red, I get a slightly better display: https://drive.google.com/open?id=1MtPm5 ... HoZ65DO_YH
Also, the "Geometry" menu is not accessible in this mode.

Even that however has lots of noise as you can see, but that might be because all the wires go to a prototyping board where I can easily swap resistors and capacitors at the minute.

In fact, this is what I tried:
- 680R on the CSync output from the console (that was my "default" setup).
- Using the composite video signal instead of CSync: no difference at all.
- 470R instead of 680R on CSync: no difference.
- 470R and a 22uF cap in series: no difference, but now the "Auto" button doesn't even make the LED flash. Same with different capacitor values between 10uF and 220uF, same with a bigger resistor.
- 1K ohm instead of 680, and no cap: no difference.
- 6 different power supplies to the GBS-8200: no difference.

Also, when in PAL mode the image is cut at the bottom if I select the RGBHV input, which as I mentioned has no settings where I can resize the picture.
I've noticed that others in this thread mentioned problems with a US Model 2 Genesis, but the solution seemed to be adjusting the values of resistor and capacitor on the CSync line. That doesn't seem to work for me.
So my fear is that even with a custom firmware I'm not going to get a usable display.

Any help or advice is hugely appreciated

You the man, Rama.

:>

Seriously, that was great from you guys.

So what's next?
I'm working on a huge project that uses the ESP32 and the STM32F103.
These are basically the big brothers of the ESP8266 and an Arduino, respectively.

So I see a lot of their benefits and shortcomings.
It's shocking, for example, how sluggish the ESP32 interrupt latency is.
But the STM32 is interesting.
Its ADC may be able to process any sync source from 0.3 to 3.3Vpp, and so the chip could act as a sync processor and timing deducer. This would be good for those weird EGA or medium res situations.

The external timing generator has seen a lot of testing here, due to that other project.
Those of you that already use it may have seen a stationary horizontal line, splat in the middle of the picture.
This is not supposed to happen. That's the tear line that should be outside the visible frame :p
I'll be looking into a solution to that next, I think!
(In the mean time, simply restart or reload a preset. 9 times out of 10, it works correctly.)

I'm an idiot, sorry: I meant a VA4 model with a BH7326AF encoder. I'll fix my original post.

Anyway, the issue is the same. I've now checked the CSync output with a scope just to make sure my system wasn't doing something funny, and I don't know much about video signals but it looks fine to me.
Maybe I just got a dodgy GBS-8200?

I had similar problems with MD and stock GBS (model 2 VA0). You should go ahead and try building the controler, everything is easily reversable.

Just go with 10µF (+ side towards console) or more + 470R (680R should work too) if you use the sync pin.

If you have sync drops or black screen after, remember to try "lock to 50/60 HDMI" and/or "Htotal++" / "Htotal--", particulary on an LCD (CRT VGAs usually go just fine).

Crap, I just pulled up pin 39 along with pin 40, on the TVIA, while starting the clock gen mod. Up with pin 39 came its pad as well. The data sheet says pin 39 is VR7. I don't see that there's a trace going to this pad. Is this going to be a show-stopper for this old GBS? (this is the one I've done the bulk of testing on over the past few years while this project has evolved, and is very hacked up as it is).

:edit: Seems to be no issue with that lifted pin/missing pin 39. You guys tell me if you see something odd. Quick test w/ Sega 32x: https://youtu.be/g9oLfDmK2UM

NoAffinity:
Tough luck, but surely good practice
There's no problem with pin39 floating and the pad ripped. The pin is a digital I/O that would be used for the digital red bit 7.
We don't need this, and the I/O driver is turned off.
Still, make sure that the pin is isolated and can't short anything else.

Fox Cunning:
Basically what Ryoandr said
Your hack with the RGBHV input is neat, I haven't managed to trick the controller like that.
The problem with this though:
The controller might still drive the RGB switcher chip (IC4) that's responsible to black screen (for the "no signal") display.
Also, it would want to limit the ADC power, which might explain the colors.
You get the RGBS problems because the controller doesn't realize that the sync signal is PAL/NTSC CSync (possibly embedded in CVBS).
It applies wrong coasting and sync separation doesn't work. It's actually a small wonder that at least some consoles work with a stock GBS.

You can solve all these problems if you install gbscontrol, while also seriously upgrading the quality

that reminds me I still need to play with using the digital IO on the tvia chip

Digital in is something I'd like to try. Slap it in a Playstation

Digital out is .. well, it's a lot of pins and then it requires working software control on top.
Not sure it's worth it.

You absolute legends!

I figured I had nothing to lose except some of my time, and the result exceeds my expectations.
I've seen other people's screenshots, but this looks more amazing than my camera can capture!


Fun fact: my GBS-8200 didn't come with a header for the I2C pins, so half the time was spent installing one:

^Hey, a 2019 model! looks great!

Sent from my SM-G955U using Tapatalk

Just wanted to join the chorus and say how awesome this mod is. Went without a hitch on a GBS8200, Version 5. I also didn't have the SDA/SDL pins but I soldered the wires directly to the pads with no fuss. Looks great, used it to record a PCB at 720p for this thread here:

viewtopic.php?f=1&t=66235

Seriously impressed at the quality - unfortunately the video doesn't do it justice 'cause of a TERRIBLE capture card (Roxio Game Capture HD Pro stinks, but it was $20 )

I don't think any of the GBS boards come with pins on the I2C pads. I just desoldered the lower JST header and moved it up

There is a bunch more of cheap GBSs on eBay, I messaged about 6 sellers, some listings were changed but only this dude got back to me:

I found three sold in his feedback, although one didn't turn up for a customer. Who wants to roll the dice