What sort of cases are these being put in or are they being used as naked PCB's ?
Solution for external Flicker fixer?
- Thread starter Harrison
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Finally I got two boards from China. One of it has this white Pixel flashing effect, one does not.
I'll try different resistors on the CSYNC-signal and a shielded cable to the Amiga.
If this does not help:
Maybe the heatsink on the CPU is not attached correctly on the board. I know this flashing pixel effect from old graphics cards for the PC where the fan stopped working and the GPU got too hot...
I'll try different resistors on the CSYNC-signal and a shielded cable to the Amiga.
If this does not help:
Maybe the heatsink on the CPU is not attached correctly on the board. I know this flashing pixel effect from old graphics cards for the PC where the fan stopped working and the GPU got too hot...
Exactly the same problem here. I suspect lack of resistors on the signal cables as I built my cable without using them. Can someone confirm that's the case?
No idea whether it'll solve the issue or not, but it might be worth running the sync signals through a TTL buffer of some kind, like the official Commodore RGB -> VGA adapter did.
When I first got my Iiyama Visionmaster Pro 410 a good many years back, I got a slight horizontal shaking of the picture when using an unbuffered adapter. I fixed it by making a buffered adapter.
Whether it'll make any difference in this case I can't say, but might be worth a try.
Ed.D
Active member
Hi Guys,
I'm interested in one of these ....might order one. I found some more info from what looks to be the manufacturer website "Gonbes".
There's an 8200 and the 8220 model. The 8220 has 2 VGA outs and the output signal pins are documented as P4 and P12 on the 8200 or P4 and P13 on the 8220.
Links:
8220
8200
ATB.
I'm interested in one of these ....might order one. I found some more info from what looks to be the manufacturer website "Gonbes".
There's an 8200 and the 8220 model. The 8220 has 2 VGA outs and the output signal pins are documented as P4 and P12 on the 8200 or P4 and P13 on the 8220.
Links:
8220
8200
ATB.
I've picked up one of these, was planning to use it with my amiga and also an old 286 PC with EGA graphics.
I've no idea how to hook it up to the EGA adapter though because the EGA pinout has 6 wires for colour- red green blue and a secondary one for each to denote 'high intensity' of each colour. This adapter only has 5 input pins, red green blue, sync and ground.
some research seems to suggest that arcade systems refer to 15KHz analog video as CGA, and 25KHz analog as EGA - as opposed to PC's which use digital TTL for both CGA and EGA.
So if this is correct, this adapter won't actually work with PC EGA? and if it accepts TTL signals at all it will only be CGA?
I've no idea how to hook it up to the EGA adapter though because the EGA pinout has 6 wires for colour- red green blue and a secondary one for each to denote 'high intensity' of each colour. This adapter only has 5 input pins, red green blue, sync and ground.
some research seems to suggest that arcade systems refer to 15KHz analog video as CGA, and 25KHz analog as EGA - as opposed to PC's which use digital TTL for both CGA and EGA.
So if this is correct, this adapter won't actually work with PC EGA? and if it accepts TTL signals at all it will only be CGA?
That's correct, you can't use TTL RGB with this converter out of the box. In the arcade world CGA and EGA only refers to the horizontal scan rate (15 and 25 KHz respectively - if I remember correctly).
You can build a simple DAC from passive components: http://sites.google.com/site/h2obsession/CBM/C128/rgbi-s-video
Of course you have to modify it to use the secondary color lines as separate intensity for each color.
You can build a simple DAC from passive components: http://sites.google.com/site/h2obsession/CBM/C128/rgbi-s-video
Of course you have to modify it to use the secondary color lines as separate intensity for each color.
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Just wondering. Has anyone found anywhere selling replacement cables for this device? I'm interested in making up a set for the ST as well as the Amiga so would need 2 sets. Initially I'm just going to use the one that came with it to make an Amiga set though.
Why not put a common socket on the end of the cable supplied and then just make connecting cables for the machines you want to use it with ?
You mean similar in look to a serial or Amiga joystick one?
If so that should work. So I would need a socket that can be mounted in a case, plus a couple of plugs to fit it for the cables, with housing. Where is best place to buy these from?
Also has anyone found a good case/box for the GBS2880? And also an external power supply? I'm thinking that would be best as I won't be able to power the device from an ST, so having it as a standalone box with a socket for different input cables would be a great solution.
If so that should work. So I would need a socket that can be mounted in a case, plus a couple of plugs to fit it for the cables, with housing. Where is best place to buy these from?
Also has anyone found a good case/box for the GBS2880? And also an external power supply? I'm thinking that would be best as I won't be able to power the device from an ST, so having it as a standalone box with a socket for different input cables would be a great solution.
@Harrison, AFAIK the VGA Input connector is pinned to accept a VGA cable so in theory (I've not tried it) you could plug a cable from the Amiga VGA adapter straight to it.
And as far as a box for the GBS-8220. I've decided to mount mine in an old DVB-T MPeg 2 TV STB casing. I'm in the middle of doing it now, will post pics when i'm finished. I plan to have a Sync Strike (buying soon) and my SLG 3000 Scanline generator squeezed in with it too. My hope is to have a SCART input (from the Sync Strike) along with the Power. And a shiny VGA connector for output. Also a space for a knob for adjusting Scanline intensity and the 4 Menu control buttons somewhere for easy access. This will then me my all-in-one Retro Console solution for modern TV's.
The problems with blanking out and wavyness in text may be sorted out with the Sync Strike... I'll let you all know if it does as its the only thing spoiling its perfectness. The other theory is software, it is possible to update these, but i've yet to find anywhere that offers a cable for the 4 pin connector or even any updated firmware.
I just wish an all in one module could be made that has built in Sync stripper and Scanlines. GBS-8440 anyone? Well whatever its called, it would make a nice and tidy "top end" converter.
And as far as a box for the GBS-8220. I've decided to mount mine in an old DVB-T MPeg 2 TV STB casing. I'm in the middle of doing it now, will post pics when i'm finished. I plan to have a Sync Strike (buying soon) and my SLG 3000 Scanline generator squeezed in with it too. My hope is to have a SCART input (from the Sync Strike) along with the Power. And a shiny VGA connector for output. Also a space for a knob for adjusting Scanline intensity and the 4 Menu control buttons somewhere for easy access. This will then me my all-in-one Retro Console solution for modern TV's.
The problems with blanking out and wavyness in text may be sorted out with the Sync Strike... I'll let you all know if it does as its the only thing spoiling its perfectness. The other theory is software, it is possible to update these, but i've yet to find anywhere that offers a cable for the 4 pin connector or even any updated firmware.
I just wish an all in one module could be made that has built in Sync stripper and Scanlines. GBS-8440 anyone? Well whatever its called, it would make a nice and tidy "top end" converter.
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Anyone had any luck fixing the pixel shifting issue?
Also noticed 2 real downsides to this device:
1. the 50 to 60Hz conversion results in slightly jerky scrolling text and games.
2. Sadly it dithers AGA output. Most of the time its unnoticeable, but it is there. One good way to see it is to enable a Copper background for Workbench. Plain as day then.
Also noticed 2 real downsides to this device:
1. the 50 to 60Hz conversion results in slightly jerky scrolling text and games.
2. Sadly it dithers AGA output. Most of the time its unnoticeable, but it is there. One good way to see it is to enable a Copper background for Workbench. Plain as day then.
I tried an Amiga to VGA adapter going into the VGA input, but on the monitor I mainly just got a green screen, sometimes with a glimpse of the Amiga screen scrambled in the background, so that didn't work. Any ideas why?
I'm at a loss. Soldered the supplied cable up to an Amiga 23 pin RGB connector, plugged it into the GBS8220 and no luck. I had the flicker of a colour image from the Amiga a couple of times in my attempts, but most of the time it is just displaying "No Signal".
I wired it up as:
Wire = Pin
Red = 3
Green = 4
Blue = 5
grey = 10 (Comp Sync)
Black = 16 (ground)
I'm powering the GBS8220 from an external 5V 2A Power Supply, so power isn't an issue,
But I'm not getting anything. I even tried 3 different monitors to see if that made a difference, but it didn't.
I wired it up as:
Wire = Pin
Red = 3
Green = 4
Blue = 5
grey = 10 (Comp Sync)
Black = 16 (ground)
I'm powering the GBS8220 from an external 5V 2A Power Supply, so power isn't an issue,
But I'm not getting anything. I even tried 3 different monitors to see if that made a difference, but it didn't.
