GBS-8220, 23DB Connectors and Leads

[hot trout]

I found the boards on ebay from china for delivery in 6 days. Would that help? Also one of the guys on here had some 23pin connectors that he might sell. I dont mind waiting a while, will be too busy over xmas anyway.

[Johan1973]

Originally Posted by hot trout

I found the boards on ebay from china for delivery in 6 days. Would that help? Also one of the guys on here had some 23pin connectors that he might sell. I dont mind waiting a while, will be too busy over xmas anyway.

Can you send me a PM with a link for the boards from china?

[hot trout]

They are in my post at the top of this thread.

[Johan1973]

I can not find the link you are referring to. I am looking around, and will try to set up a supply of boxes, gbs 8220s etc. So will take a while to pull things together. Will put message here on forum when I have some ready to sell.

[prowler]

The link is here.

http://www.ebay.co.uk/itm/1809119379...84.m1423.l2649

[Johan1973]

Thanks. I guess I am going blind...

[Johan1973]

BGS 8220's ordered; Sellers estimate; 40 to 50 days delivery time.

[roy bates]

if anyone is interested in the rgb port connectors, this guy has 39 left with hoods.


http://www.amibay.com/showthread.php...pin+connectors

[Johan1973]

I have been using 25 pins cut down to 23 pins. I get those for €1 each or so. Easy to do.
Will be using standard EGA 9pin dsub as input on the boxes.

[hot trout]

Any update on this?

[Johan1973]

I have received the boards. And am using them now.
They are ok for amiga. They have scandoubler/flicker fixer. However you get some artifacts with the flickerfixer. Yet that is far better than the interlace flicker.
Due to how the boards are built, it is a bit tricky to box them. So I am looking at that now, how to solve it.

[hot trout]

Great news, looking forward to this.

[Johan1973]

Unfortunately I have to respond with some bad news. I have spent the last two days testing these boards, with Amiga, ZX spectrum +2, Xbox 1, etc. And the result is not that great.

While they are ok for the amiga. They have some serious issues. Especially when dealing with interlacing. And then also issues when you connect it to computers that does not use interlace. There needs to be more revisions or a better design for better picture quality and less quirks. Since they are cheap, they are an ok alternative to use for amiga until you have something better. Right now I can not find any rgb to vga converters that are better, but new models are on the way. I will not make any boxed versions of these cards and offer them. It simply is not worth the hassle. To much work vs the gain. I will however offer assistance in helping people wiring these up to use for amiga.

On the 23 pin video connector, connect Red to pin 3, Green to pin 4, Blue to pin 5; Black (ground) to pin 20, Grey and Yellow (sync) to Pin 10 (composite sync). The board will just not work with separate horizontal and vertical sync.

List of issues;
1. Interlace flicker fixer artefacts
2. Random white dots in image on black background
3. Just simply to slow and unable to handle computers that use non-standard timings, but ok for amiga.
4. Output quality of the image is a little below the built in scandoubler in the Amiga 3000, though it is superior in that it actually have a flicker fixer that removes the flicker.

And the good;
1. You get image on your VGA monitor. It works with LCDs, though CRTs are perhaps better.
2. Output quality is not worse than an old CRT tv fed with RGB.
3. Easy to wire up despite total lack of instructions.
4. Are able to handle 15Khz and 24Khz input signal.

[Johan1973]

An update

These boards are twitchy when it comes to input voltage. It has to be silly stable and clean. I have added an induction coil and caps to filter the voltage, and that seems to clean up the random white dot issue quite a bit.

[Johan1973]

Hot Trout: If you want, I can wire one up for you. But you need to send it to me with connector so I can solder it. And you will have to get power supply and case yourself. There are some arcade stores online that sells plastic cases for these, its two pieces of plastic with stands.

http://www.arcadeforge.de/index.php?...ejg8l42f7eiee5

[Johan1973]

If you have the random white dot problem, this is how I solved it;

+ from power supply |- Inductor -| + to GBS 8220
Electrolyte 1000uF = = Electrolyte 1000 uF
- from power supply |- Inductor-| - go GBS 8220

The inductor is just a transformer from a power supply that is hooked up so that you run + in parallel with - through the two coils, and as such the induction reduce noise. The caps adds stability and acts as filters.

You connect caps in parallel on the input and output side of the induction coil.

Hi Johan!
I'm new to this retro computer scene (even if I am almost 60), as I am helping my son, who has decided to start collecting retro consoles. Imagine if I had seen this forum before I bought the GBS-8220. Still I got it up and running and got a great picture except for those spots. The higher the resolution, the worse they are.

This is apparently something you have solve by applying a "filter" to the power supply. I bought a cheap adapter at ELFA that gave the 5V/2A I required. Could I apply the same solution to my board with this adapter?

I am afraid I don't really understand your schematics above, but as I understand it, all I have to do is solder the capacitors and inductor (where do I get that? What value?) parallell to each other, on to the power connector (5V + GND) on the GBS-8220 board. I would appreciate it if I could get a photo, to confirm this.

Thanks a lot in advance!

/MacDknife

[SS454]

Just grab a second hand HD sky box. Plug the Amiga in through scart, plug the vga monitor in to an adapter for the HDMI socket. Done.

Thanks for the suggestion SS454! Solved that TV problem a while back though. The thing is that my son specificly wants to be able to use an old extra monitor he has. Unfortunately they don't come with HDMI. All suggestions are welcome though. Many of us (myself included) go for the more conventional approach and sometimes forget to try something different...
: P
/MacDknife

[SS454]

HDMI carries VGA. Get a lead with a HDMI connector on one end, and a VGA connector on the other. I even said so