GBS-8220 to SGCPU or Geneve

[+acadiel]

Anyone have experience hooking one of these 15Khz converters up to a SGCPU (99/4P) or a Geneve?

 

http://www.amazon.com/SainSmart-GBS-8220-Arcade-Video-Converter/dp/B0051SLJAG/ref=sr_1_1?ie=UTF8&qid=1396011788&sr=8-1&keywords=gbs8200

 

If so, please share pinouts, etc.

 

EVPC (from http://home.arcor.de/system-ninety-nine-user-group/evpc/evpc1hw.pdf)

 

 

epvc2 (from http://home.arcor.de/system-ninety-nine-user-group/evpc/evpc2hw_e.pdf):

 

 

Geneve: (from http://ti99.collosumus.net/ti99/hardware/gvideo2.aspx)

 

 

 

Edited March 28, 2014 by acadiel

[Gazoo]

 

^^^ piece of crap made by Ambery. ^^^

 

Let me know how this thing works out for you. You may know that I tried the one pictured in my post (around $100) and the results were horrible. Our community really needs a device like this that actually works. Either that, or an F38A, which will likely not see the light of day. A working RGB to VGA converter for around $25, WOOHOO!

 

Gazoo

 

[Gazoo]

I did a little research on this and found out a few things.

 

The connection you should use is the 5 pin header on the lower left corner of the board as it's viewed in your photo.

Connections are pretty simple, just match up the 5 input wires.

 

Apparently the device is designed for Jamma boards, which output negative sync. The 9938/58 outputs positive sync.

This board may or may not work depending on if it can read the positive sync. This was the problem with the Ambery converter.

I tried a sync inverter as well as a LM1881 to process the sync, but the results weren't good. You might want to contact the manufacturer to find out if the board accepts positive sync.

 

Gazoo

 

[+Ksarul]

Actually, looking at the connectors carefully, shouldn't you be using the 8-pin RGBS header right next to that 5-pin header? That's what the Amiga uses. . .see this thread:

 

http://eab.abime.net/showthread.php?t=66922

[Gazoo]

Actually, looking at the connectors carefully, shouldn't you be using the 8-pin RGBS header right next to that 5-pin header? That's what the Amiga uses. . .see this thread:

 

http://eab.abime.net/showthread.php?t=66922

 

Message #9 indicates the 5 pin header is used for Amiga. Or am I reading it wrong?

 

Gazoo

[+Ksarul]

Later in the thread they advise against using the 5-pin connector. Also look at the pictures in post #7, as they show it connecting to the 8-pin. The three colored wires are the R-G-B lines going to the first three positions, the Gray wire is CSYNC, and the Black wire is Ground.

[Gazoo]

Later in the thread they advise against using the 5-pin connector. Also look at the pictures in post #7, as they show it connecting to the 8-pin. The three colored wires are the R-G-B lines going to the first three positions, the Gray wire is CSYNC, and the Black wire is Ground.

 

Ok, then. I just hope it works.

 

Gazoo

[Gary from OPA]

 

Ok, then. I just hope it works.

 

Gazoo

 

It will, just that alot of these 'scandoubles' converters give you not so perfect picture, the quailty needs to be improved, there is few models that have good picture, with no fuss edges or bleeding colors, but they are rare.

 

Some get better by removing them from plastic case and installing them in shielded metal box, and grounding and good shielded cables help, and the source of 5volts or 12volts needs to be well grounded and shielded also.

[+OLD CS1]

I wonder if the CGA input will work with other machines with RGBI output.

[Gazoo]

 

It will, just that alot of these 'scandoubles' converters give you not so perfect picture, the quailty needs to be improved, there is few models that have good picture, with no fuss edges or bleeding colors, but they are rare.

 

Some get better by removing them from plastic case and installing them in shielded metal box, and grounding and good shielded cables help, and the source of 5volts or 12volts needs to be well grounded and shielded also.

 

The tech support at Ambery told me theirs would work, too.

So this is still a crapshoot until Acadiel tells us whether or not it works.

 

Gazoo

[+Ksarul]

Well, we also have some possible confirmation from the Amiga site too--as several of those folks are using it, and we can use their monitors. . .still no guarantee--but close.

[+arcadeshopper]

I have had good luck with the SCART to HDMI adapter on my amiga.. that might work for the Geneve etc with a SCART cable. I made one for my Geneve to use with the samsung 910mp

[Gazoo]

I have had good luck with the SCART to HDMI adapter on my amiga.. that might work for the Geneve etc with a SCART cable. I made one for my Geneve to use with the samsung 910mp

 

Let us know if you ever try the HDMI converter with the Geneve, and what model it is. Also, does it stretch the image, or provide black bands at the sides for the proper perspective?

 

Gazoo

[+arcadeshopper]

 

Let us know if you ever try the HDMI converter with the Geneve, and what model it is. Also, does it stretch the image, or provide black bands at the sides for the proper perspective?

 

Gazoo

 

one off ebay: http://www.ebay.com/itm/Scart-HDMI-to-HDMI-720P-1080P-HD-Video-Converter-Adapter-Box-For-HDTV-DVD-STB-/350735096556?pt=US_Video_Cables_Adapters&hash=item51a970daec

 

Looks stretched on the amiga.. fills the screen horiz.

Edited April 5, 2014 by arcadeshopper

[+acadiel]

 

one off ebay: http://www.ebay.com/itm/Scart-HDMI-to-HDMI-720P-1080P-HD-Video-Converter-Adapter-Box-For-HDTV-DVD-STB-/350735096556?pt=US_Video_Cables_Adapters&hash=item51a970daec

 

Looks stretched on the amiga.. fills the screen horiz.

 

Here's a Youtube video:

 

 

Gives me more hope....I have a feeling if you want a professionally looking built one, we could take one of the Amiga ones and put a different end on it:

 

http://amigakit.leamancomputing.com/catalog/product_info.php?cPath=21_72&products_id=226

[+arcadeshopper]

 

Gives me more hope....I have a feeling if you want a professionally looking built one, we could take one of the Amiga ones and put a different end on it:

 

http://amigakit.leamancomputing.com/catalog/product_info.php?cPath=21_72&products_id=226

 

You can buy scart connectors off ebay.. I had to get one to make a cable since the geneve required an external 3v power supply to select rgb on the scart.

[eck]

EVPC (from http://home.arcor.de...pc/evpc1hw.pdf)

epvc2 (from http://home.arcor.de...evpc2hw_e.pdf):

When I am looking at the pinouts that acadiel posted here, I am spotting a difference within pin 8. I have no idea in which league the Geneve plays here, but my V9938 uses a digital Sync, which prohibits the usage of these converters. Does this depend on V9938 vs. V9958 or is it possible to modify the output of the EVPC to analog Sync? I am hoping that someone can help me here.

[+jedimatt42]

I have the sister to the GBS 8220, the GBS 8200. And I'm trying to hook it up to my Geneve for VGA output.

 

The composite-sync signal ( pin 8 ) on the Geneve seems to be incompatible. But pin 4 is a full composite-video signal, and there is a little chip that should be able to turn that into a good composite-sync signal. the LM1881.

 

Has anyone tried this? had experience with the LM1881 sync splitter chip? Or used a confirmed alternative technique to get good high-res output from a geneve on a VGA or HDMI display?

 

I think this current thread is saying that Arcadeshopper has used SCART cables with SCART to HDMI device with his Geneve, but I cannot tell from the language. Was that with a Geneve or just with Amigas?

 

Resources:

http://www.gamesx.com/misctech/lm1881.htm

https://ianstedman.wordpress.com/gbs-82xx-experiments/

[+jedimatt42]

Looks like I won't know how the sync splitter chip works for me until next month... Ordered through ebay from China today.

 

I put the sync from the geneve under the oscilloscope, and it makes me think this should work out. ( I'm hopeful ) The geneve sync looked fairly noisy. And I was able to get a recognizable cursor blinking using the composite-video line as sync. Just too noisy to be useful.

[+jedimatt42]

I received the LM1881 chips Friday, and was able to wire it up tonight. It was successful. Mostly.

 

The sync is totally cleared up. I wired up the LM1881 following this diagram: http://www.gamesx.com/misctech/lm1881.htm

 

I powered that little circuit off of the GBS8200 power header as I'm using the barrel connector to supply power to the GBS8200.

 

I said mostly, because I don't get any red, and I haven't nailed down if that is my Geneve, or the GBS8200 that has an issue. I'll have to break out the oscilloscope and see if a red signal is getting to the GBS board at all. I've already double checked my 8 pin din cable, and my little LM1881 circuit. The lack of red was apparent when I entered GPL and brought up the TI title screen. No amount of adjustment on the GBS8200 fixes it (there are 3 little intensity controls for R G and B). So it must be an input problem.

 

Browsing the internet, it looks like a lot of the SCART cables have the LM1881 embedded in them.

 

More fun to be had.

 

Anyway, the sync signal can be cleaned up and made compatible using this LM1881 circuit.

[+InsaneMultitasker]

I received the LM1881 chips Friday, and was able to wire it up tonight. It was successful. Mostly.

 

The sync is totally cleared up. I wired up the LM1881 following this diagram: http://www.gamesx.com/misctech/lm1881.htm

 

I powered that little circuit off of the GBS8200 power header as I'm using the barrel connector to supply power to the GBS8200.

 

I said mostly, because I don't get any red, and I haven't nailed down if that is my Geneve, or the GBS8200 that has an issue. I'll have to break out the oscilloscope and see if a red signal is getting to the GBS board at all. I've already double checked my 8 pin din cable, and my little LM1881 circuit. The lack of red was apparent when I entered GPL and brought up the TI title screen. No amount of adjustment on the GBS8200 fixes it (there are 3 little intensity controls for R G and B). So it must be an input problem.

 

Browsing the internet, it looks like a lot of the SCART cables have the LM1881 embedded in them.

 

More fun to be had.

 

Anyway, the sync signal can be cleaned up and made compatible using this LM1881 circuit.

 

There is a jumper on the neck of the Geneve that determines whether or not the RED signal passes to the 8-pin DIN connector. Have you checked its setting?

[+jedimatt42]

Funny you should mention the jumper, I was just hanging up some RED Christmas ornaments, and that caused some mental recall. I had read about the jumper in the manual. I moved the jumper, saw all that wonderful color, and was just popping on here to report that the problem is solved!

 

The color is good, now I can see the hot dogs or whatever they are in Burgertime

 

Thanks for the tip!

 

So, in summary, with an LM1881 chip used to clean up the composite-sync signal from the Geneve, the GBS-8200 up scalar can be used to connect a Geneve to a VGA display.

 

There are some artifacts I notice in Parsec. But it works respectably.

 

-M@

[+InsaneMultitasker]

Funny you should mention the jumper, I was just hanging up some RED Christmas ornaments, and that caused some mental recall. I had read about the jumper in the manual. I moved the jumper, saw all that wonderful color, and was just popping on here to report that the problem is solved!

 

The color is good, now I can see the hot dogs or whatever they are in Burgertime

 

Thanks for the tip!

 

So, in summary, with an LM1881 chip used to clean up the composite-sync signal from the Geneve, the GBS-8200 up scalar can be used to connect a Geneve to a VGA display.

 

There are some artifacts I notice in Parsec. But it works respectably.

 

-M@

Could you share a picture or two of the output? I'm certainly curious Sounds like this has potential for other 9938/9958 based devices, too.

[RickyDean]

Could you share a picture or two of the output? I'm certainly curious Sounds like this has potential for other 9938/9958 based devices, too.

Yeh like my TIM

[+jedimatt42]

Here is a short video of the output in MDOS 80 column and in GPL mode.

I zoom in on a few artifacts that I'm not sure who's fault they are...

 

 

video link: https://goo.gl/photos/8eDQpAt38YwU1fmf8

 

Here is the hardware. A little solder-breadboard that has the LM1881, 2 0.1uf caps, and a 680ohm resister. I also wired my DB9 harness to it ( for my monitor cable ) and the harness that came with the GBS8200. I used the power harness to steal power from the upscaler.

 

 

So, my little board is basically a $5 version of this Sync Strike product, without all the extra connectors. I got 5 of the LM1881 chips off ebay for $3.

 

sync strike: http://arcadeforge.net/Scaler-and-Strike-Devices/Sync-Strike::15.html

 

And if you want a complete off the shelf solution: http://arcadeforge.net/SLG-in-a-Box/SLG-in-a-Box::71.html

 

I'm about to order the SLG3000 scan line generator because I think that will help clean up the appearance of PARSEC. When I figure out how to grab a frame some some video, I'll highlight what I'm talking about. Something is 'sharpening' the image in a way that cause a little bounce in side scrolling.