GBS 8200/8220 CFW Project

[dooklink]

First off, many thanks for starting this great project! I'm attempting to use it to convert a 400x300 19khz signal coming from an old piece of HP test equipment to drive a 640x480 lcd panel. I'm using an Arduino mini with the standard Arduino library to send the settings.
I've managed to find the correct set of settings but I can only get things to work if I first let the GBS cpu boot up. That is, things work fine if I let the cpu boot, then short out the i2c pin, and then send the settings. If however I start the board with the i2c pin shorted and then send the settings, the screen fills with a checkerboard of noisy green squares - even with no signal. It almost seems like there is something else on the board that needs to be initialized.

I figured out what the issue was. I wasn't sending the initial set of register writes specified in start.txt. I am curious as to why these are needed when one then goes and rewrites every register in video processor.

I believe it is due to some of the registers using latch bits. I haven't bothered to fix this yet to create a routine to flip all the latch bits and reload all values.

[Solo761]

It could be the video timings themselves, but I would guess it it most likely the sync pulses. Perhaps the sync periods are not long enough. On the RPi version you can change this in the geometry menu.

You could try extend the sync periods in the array from the header file. I'll have to go look at what you will need to change if you can't find it yourself. Just let me know what you are using.

For some reason I can't get RPi version to work :/. Back in December it worked fine, I tried to reinstall it 5-6 times, on different raspbian releases, but monitor simply doesn't turn on, with arduino and port of mybook4's firmware (and various settings I 288p converted to it) it works fine.

[retroware]

First off, many thanks for starting this great project! I'm attempting to use it to convert a 400x300 19khz signal coming from an old piece of HP test equipment to drive a 640x480 lcd panel. I'm using an Arduino mini with the standard Arduino library to send the settings.
I've managed to find the correct set of settings but I can only get things to work if I first let the GBS cpu boot up. That is, things work fine if I let the cpu boot, then short out the i2c pin, and then send the settings. If however I start the board with the i2c pin shorted and then send the settings, the screen fills with a checkerboard of noisy green squares - even with no signal. It almost seems like there is something else on the board that needs to be initialized.

I figured out what the issue was. I wasn't sending the initial set of register writes specified in start.txt. I am curious as to why these are needed when one then goes and rewrites every register in video processor.

I believe it is due to some of the registers using latch bits. I haven't bothered to fix this yet to create a routine to flip all the latch bits and reload all values.

How did you figure out what to initially send? I'm still having problems with my separate sync settings. If I use start.txt with my composite sync setting things seem to go ok. When I use start.txt with my separate sync settings I get nothing but screen trash.

I'm still in awe that you were able to figure out how to use this chip!

[dooklink]

How did you figure out what to initially send? I'm still having problems with my separate sync settings. If I use start.txt with my composite sync setting things seem to go ok. When I use start.txt with my separate sync settings I get nothing but screen trash.

I'm still in awe that you were able to figure out how to use this chip!

I just copied the original register values and startup sequence. I've only adjusted the output and processing, not the input capture settings, apart from the coast values.

Are you wanting to adjust the input sync or output sync?
Also I spent a good deal of time reading the programming manual and looking up VESA and 15kHz video timings to get started.

[dwards]

Dooklink,

Will you continue to add different resolutions to future versions? Or are you focusing more on TV resolutions than PC monitors, which are pretty much now all covered? For example my screen has a less common 1440 x 900 @ 60Hz. I was hoping to get a native support but i'm probably one of the few with these pixels.

Thanks!

[dooklink]

Dooklink,

Will you continue to add different resolutions to future versions? Or are you focusing more on TV resolutions than PC monitors, which are pretty much now all covered? For example my screen has a less common 1440 x 900 @ 60Hz. I was hoping to get a native support but I'm probably one of the few with these pixels.

Thanks!

Funny you mention that. My main monitor just died and it was 1600x900. Which I don't think is even a standard VESA resolution. my second monitor is 1440x900 which is a VESA standard resolution.

The real issue is not the resolution but the aspect ratio. 16:9, 4:3, 5:4, 16:10 etc. The monitor scaling up from say 640x480 is not that big of an issue. The problem is many monitors that are not 16:9 will not have a legacy 4:3 crop mode. I'm not sure what to do about that.

My suggestion in the mean time is to use the highest resolution you can and use the scaling controls, in gbs-control to fix the aspect ratio. If you want to use a scanline generator then you will almost certainly need 4:3 support on the monitor.

[dwards]

Cool, so there is a chance you will develop for that resolution since you have the same monitor. FYI, there is a way to do scanlines beyond 480p with the "T-SLG v1.6 - Main" http://godlikecontrols.com/. I do have this device and it works for me. It may not be as perfect as the SLG3000 but it handles higher resolutions. I have not had a chance to try the 0.3 code but looking forward to it. I am waiting for a replacement fuse for SNES since I accidentally fried it. Thanks for the response!

[_tweak]

It appears that mine 8220 has somewhat of a different problem than species and white noise; its more of a whirling twirly problem with all graphics; looks like interference, however there is nothing that could interfere with the 82xx.

The problems with the whirly pattern is not visible on the OSD of the 82xx so it must be something from my device, up to and including the actual conversion (but before OSD is applied).

This is the 82xx running on an Amiga:

[_tweak]

I just did a video of the problems I am facing with the GBS 8220 (HD9820) with Amiga RGB output and CSync. Its found here https://youtu.be/3gM8z_TD2Xc (note: must be highest quality to see the moving pattern)

It looks like interference, but I've moved the whole arrangement around quite a bit; used different PSUs for both Amiga and GBS, switched out the Amiga a few times - same result. I also tried I2C Arduino overrider - the picture got thought but the quality of the actual image stayed the same, sadly.

[kynrek]

Will a older cheap Raspberry Pi Model B+ http://www.microcenter.com/product/4382 ... Pi_Model_B work?

[hellbelly]

I just did a video of the problems I am facing with the GBS 8220 (HD9820) with Amiga RGB output and CSync. Its found here https://youtu.be/3gM8z_TD2Xc

It looks like interference, but I've moved the whole arrangement around quite a bit; used different PSUs for both Amiga and GBS, switched out the Amiga a few times - same result. I also tried I2C Arduino overrider - the picture got thought but the quality of the actual image stayed the same, sadly.

I have 2 8220s that do this, and both stop doing it if I change the output resolution to 800x600 - both are stable then.

[dooklink]

Will a older cheap Raspberry Pi Model B+ http://www.microcenter.com/product/4382 ... Pi_Model_B work?

No reason it wouldn't, if anything it is more likely to. The only model I wouldn't expect to work would be a RPi 2, but it may work as well.

[_tweak]

I have 2 8220s that do this, and both stop doing it if I change the output resolution to 800x600 - both are stable then.

Sadly, all resolution is the same result.

Your 8220's do they say "GBS 8220" on the PCB silkscreen, or "HD 9820" ? What power supply do you use (Size + vendor) ?

[kynrek]

It worked like a charm with the pi B+, I can't believe the quality! It looks amazing in 1080p Thank you so much! excellent work!

[dwards]

It appears that mine 8220 has somewhat of a different problem than species and white noise; its more of a whirling twirly problem with all graphics; looks like interference, however there is nothing that could interfere with the 82xx.

The problems with the whirly pattern is not visible on the OSD of the 82xx so it must be something from my device, up to and including the actual conversion (but before OSD is applied).

I see the exact same problem on a HD9820. I still need to try out an authentic GBS8220.

[hellbelly]

I have 2 8220s that do this, and both stop doing it if I change the output resolution to 800x600 - both are stable then.

Sadly, all resolution is the same result.

Your 8220's do they say "GBS 8220" on the PCB silkscreen, or "HD 9820" ? What power supply do you use (Size + vendor) ?

One is an HD9820, the other is an 8220 v3 that used to work fine. PSU wise, a mixture of 5v at 2a or 4a. Delta, I.T.E, with and without ferrite bead.

There's a post on an Amiga board that details some fixes to try, I keep meaning to work my way through them.

[mikeyb]

This project is great! Thanks for making this available for free. I hooked it all up pretty quickly, everything looks so much better than with just the GBS 8220. Is there any way to get this to boot straight into video mode and not into menu mode? It would be great to be able to run it without a keyboard after it's been configured.

[_tweak]

One is an HD9820, the other is an 8220 v3 that used to work fine. PSU wise, a mixture of 5v at 2a or 4a. Delta, I.T.E, with and without ferrite bead.
There's a post on an Amiga board that details some fixes to try, I keep meaning to work my way through them.

I ended up getting a refund from the seller. Thats one way of solving the problem.. or...

[kynrek]

I have had my GBS-8200 and Raspberry PI setup working great for about a week. I just noticed that when I Play Rayman on my Saturn (I think it's a PAL copy on my NTSC system) that the bottom of the screen gets cut off when running in 240P60hz -> 1080P. and If I try any of the 50hz options the picture is all scrambled. I am wondering if my Saturn is putting out 288P at60Hz? Would it be possible to get a .set file for this so I can try it?

Thanks,

[yxkalle]

What kind of cable do I need for component output?

[Phewop]

I am trying to get a GBS 8200 board working on a Printing Press Console that is made by FUGI and the original monitor was a Sharp cz-603d that was only used on this printing press console and also a NEC x68000 gaming system that was only sold in Japan. The console appears to have an old CGA board which outputs R, G, B, HS, VS,and GND. I am using the P11 connector of the 8200 v4.0 and cannot seem to get it to lock in on the sync.

I am not trying to get extreme graphics as the console output was only for seeing the location of the press cylinders, water settings, and ink settings. (nothing that graphically demanding). The original monitor was a multi-sync which used either 15khz or 31khz signals. the GBS 8200 shows the image from the CGA board and I can see the ink and water settings, but it keeps rolling. you can see a video of it here.

https://www.youtube.com/channel/UC7IbEM ... BhhRqld6qQ.

does this look familiar to anything you guys have seen with tryng to get a 15khz signal to work?

[Phewop]

I am trying to get a GBS 8200 v4.0 board to work with a CGA adapter made by fugi that was used in a printing press console. The console was made by fugi and the CGA board fed information to a monitor showing where the print cylinders, water settings and ink settings were currently set. The console came with a Sharp CZ-603d multisync (15khz, 31khz) and the monitor was only used on this printing console and on a Japanese gaming system only sold and distributed in Japan (NEC x68000). The board has the following wires..R, G, B, HS, VS, and GND. I have wired into the 8200 using P11 and also joined the sync's and tried P3 but cannot fully lock in on the signal. I can see the type from my console (ink, Water, Unit, Setting) but it continuously rolls. I have a video of it posted here
https://www.youtube.com/watch?v=vboSvlT ... load_owner

The program that controls the printing units is not that graphically demanding. Just some type showing current settings. Is there something I'm missing on getting this to sync? does this look like anything that anyone on this forum has experienced?
any help and direction would be greatly appreciated.

[dwards]

What kind of cable do I need for component output?

The below monoprice link worked for me, but if you read further back there are some adjustments that need made to get proper component signal levels. I got a picture but it did seem a little washed out so I stuck with VGA.

http://www.monoprice.com/product?c_id=1 ... 1&format=2

dooklink, any updates to CFW on rPi or flashing to the GBS?

[flagoss]

I just tested the Digispark Pro adaption on a Arduino and it worked pretty well. Nice work guys !

[Helder]

An IR receiver was added to the board and I bought a cheap IR remote to control the above settings.

After adjusting the image, the settings can be saved into the microcontroller's onboard EEPROM by selecting a save button (the 200+ button on the remote I'm using) and then pressing the desired bank (button 1-9). Saved settings can be loaded by pressing the bank (button 1-9).

I'm thinking about designing a small printed circuit board which contains the microcontroller (and its peripherals) and would clip into GBS (similar to the pictured prototype, but probably more compact). I'd need to get at least 10 boards made, so if anyone's interested let me know.

Any chance you can post the schematic you used for the board you made? I'd be interested in designing one myself and where did you get that IR Remote? Can any IR Receiver work or does it have to be the NEC brand?

[Will]

My board is a bit different than the other CGA to VGA scalers, it has this additional 9 pin connector on it

http://img.alibaba.com/img/pb/710/882/6 ... 10_965.jpg

But I got it working, only issue I seem to be getting his a random vertical jump on the image, which you can see here, any ideas how to stop this from happening? Looks like it's just a SNES issue, no problems on PS1.

http://webm.land/media/806a.webm

[mikeyb]

Look like a sync issue. You can try running the sync signal through a sync cleaning circuit like the LM1881 before feeding it to the GBS. It should help, probably good to make it switchable though if you plan on keeping it.

[Will]

Look like a sync issue. You can try running the sync signal through a sync cleaning circuit like the LM1881 before feeding it to the GBS. It should help, probably good to make it switchable though if you plan on keeping it.

I do have a LM1881 installed on my scaler, I guess I could try N64 to see if it's something to do with my cable.

e: no issues with N64, so it's something wrong with my SNES sync. This doesn't happen on the original firmware, so I dunno what's up.

[mikeyb]

You could try a 1k resistor in line with the sync signal before/after the LM1881 to see if it helps.

[Will]

You could try a 1k resistor in line with the sync signal before/after the LM1881 to see if it helps.

I used a 10K pot to try multiple values and it didn't help, still had the jump in the picture.

Before the LM1881 if I set the resistance too high sync would cut out and after the LM1881 it changed nothing.

I put a 560uf cap (it's what I had lying around) before the LM1881 and it seemed to reduce the frequency of the jumping but not eliminate it entirely, so it's not as annoying as before at least.