GBS-8220 RGB TO VGA Converter

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flyer.gio
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Re: GBS-8220 RGB TO VGA Converter

Post by flyer.gio »

vanpeebles wrote:Have you tried the wiring the cable up to the settings I posted? :)

yes, I did... nothing to do :cry:


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Dave
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Re: GBS-8220 RGB TO VGA Converter

Post by Dave »

flyer.gio wrote:
Dave wrote:The chipset on the board fully supports PAL - your vendor is incorrect.
Do you have a datasheet for that chipset ?
I do.

What seems most likely from your described problems is that when used with a PAL input, the board draws slightly more power than with NTSC - if your power supply is marginal is could draw enough current to resync NTSC but not PAL. Just a wild guess as this was the only hold-up I experienced.


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flyer.gio
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Re: GBS-8220 RGB TO VGA Converter

Post by flyer.gio »

Dave wrote:
flyer.gio wrote:
Dave wrote:The chipset on the board fully supports PAL - your vendor is incorrect.
Do you have a datasheet for that chipset ?
I do.

What seems most likely from your described problems is that when used with a PAL input, the board draws slightly more power than with NTSC - if your power supply is marginal is could draw enough current to resync NTSC but not PAL. Just a wild guess as this was the only hold-up I experienced.
mmmm... I think my psu is good enough for that board...
do you have a link to download the datasheet ?
thanks a lot


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Dave
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Re: GBS-8220 RGB TO VGA Converter

Post by Dave »

It's on paper and came with my unit. I can scan it next time I am by a scanner.


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flyer.gio
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Re: GBS-8220 RGB TO VGA Converter

Post by flyer.gio »

Dave wrote:It's on paper and came with my unit. I can scan it next time I am by a scanner.
do you mean this ? http://www.jammaboards.com/faq/file.php?id=1

I am looking for something more detailed...


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vanpeebles
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Re: GBS-8220 RGB TO VGA Converter

Post by vanpeebles »

What is the specs of your PSU for the board? How many amps? I don't have a DVD to try with that cable but it also works fine on my speccy +3.


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flyer.gio
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Re: GBS-8220 RGB TO VGA Converter

Post by flyer.gio »

vanpeebles wrote:What is the specs of your PSU for the board? How many amps?
http://cpc.farnell.com/gw-instek/psm-20 ... dp/IN04427


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vanpeebles
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Re: GBS-8220 RGB TO VGA Converter

Post by vanpeebles »

Hehehe that should do the job! :oops:


nichtsnutz
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Re: GBS-8220 RGB TO VGA Converter

Post by nichtsnutz »

Hello all,

I do not own this board but could write something about that:
The board seems to work properly only with some QLs, maybe because of tolerances of some components on the board or on the QL.
I have two different ULAs with part markings CLA2345 and CLA2310.The latter seems to be the older one.The ULAs differ in their CSYNC Signal.The CLA2310 has embedded HSYNC pulses during the VSYNC whereas the CLA2345 does not.This could be a source of error.Modern scaler chips have to regenerate the pixel clock from the CSYNC signal.They use a PLL to do so.High speed PLLs as the ones that will be inside the GBS8220 board are very sensitive when the CSYNC signal can not be transformed into a stable train of pulses and may syncout.

If you have a CLA2345 inside your QL then maybe try to find a CLA2310 and try again.

But I can not give you any guarantee,I do not own a GBS board.

If you are Interested I have some timing diagrams of the sync signals of the ULAs here:

http://www.flickr.com/photos/atari600xl ... otostream/

Greetings,
Vassilis


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flyer.gio
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Re: GBS-8220 RGB TO VGA Converter

Post by flyer.gio »

nichtsnutz wrote:Hello all,

II have two different ULAs with part markings CLA2345 and CLA2310.The latter seems to be the older one.The ULAs differ in their CSYNC Signal.The CLA2310 has embedded HSYNC pulses during the VSYNC whereas the CLA2345 does not.This could be a source of error.Modern scaler chips have to regenerate the pixel clock from the CSYNC signal.They use a PLL to do so.High speed PLLs as the ones that will be inside the GBS8220 board are very sensitive when the CSYNC signal can not be transformed into a stable train of pulses and may syncout.
Hi Vassilis,

thanks for your answer, this is very interesting, I will work around that.
I have the CLA2310 in my QL... so would be interesting to know if the QLs working with that board have the CLA2345 or not (maybe vanpeebles can let me know ;) ).

ciao!


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